JP6157112B2 - Caisson float prevention member and installation method of caisson float prevention member - Google Patents

Description

  The present invention relates to a floating prevention member provided on a side wall of a caisson constructed by being submerged in the ground.

  Conventionally, when constructing a shaft or the like in the ground, a caisson housing, that is, a tubular housing is used. The caisson constructed by press-fitting and submerging the frame receives buoyancy from the groundwater from the bottom plate provided at the bottom of the caisson body. This buoyancy may cause the caisson body to lift from the predetermined depth toward the ground.

  Therefore, the conventional caisson is configured such that the weight of the casing is increased so that the caisson body does not lift from a predetermined depth against the buoyancy, that is, the weight of the caisson body is greater than the buoyancy. ing. Specifically, the thickness of the side wall of the casing constituting the caisson main body is set to be larger than the thickness necessary for ensuring the strength of the casing itself. As a result, the caisson can be stably installed at a predetermined depth against the buoyancy.

  However, since the conventional caisson places concrete in the place where the caisson is installed and manufactures the casing, the caisson construction period becomes longer. Further, the manufacturing cost of the casing increases because the thickness of the side wall of the casing, that is, the thickness of the concrete is increased beyond the required strength of the casing in order to increase the weight of the casing.

  Therefore, in order to shorten the caisson construction period and reduce the manufacturing cost, the segment is manufactured at the factory, and the plurality of segments are connected to each other in a ring shape at the installation location to assemble a ring-shaped casing, that is, the casing, and the installation A segment press-fitting method is known in which caisson is constructed by press-fitting into the ground from the ground surface of the place.

  The segment is usually made of metal (generally iron) thinly in consideration of transportation and cost from the factory to the installation location. For this reason, the caisson constructed by the segment press-fitting method is lighter than the caisson constructed of concrete, so it is easily affected by the buoyancy, and the caisson can not resist the buoyancy by its own weight. It has the disadvantage of floating up. For this reason, there is a caisson that holds the caisson at a predetermined depth in the ground by using an earth anchor that is used when the housing is press-fitted and set (for example, Patent Document 1).

  The caisson described in Patent Document 1 is provided with a bracket on the outer periphery of the segment above the segment after press-fitting and sinking the segment using a ground anchor installed deep in the ground as a reaction force. By fixing the steel wire of the earth anchor to the bracket, the caisson can be held at a predetermined depth by the reaction force of the earth anchor even if the caisson tries to rise due to the buoyancy of groundwater.

  However, in the caisson described in Patent Document 1, the earth anchor installed deep in the ground must be left as a permanent structure. For this reason, when developing the underground space near the caisson, the earth anchor may interfere with the work, or the caisson is damaged by the steel wire between the earth anchor and the bracket due to the work. May not be able to resist the buoyancy and the caisson may be lifted.

  Some of them do not use an earth anchor as a reaction force against the buoyancy (for example, Patent Documents 2 and 3). In the caisson described in Patent Document 2, after excavating and discharging the earth and sand inside the circular casing, a plurality of steel plates are mechanically extruded so as to protrude from the bottom of the circular casing to the outside of the caisson. The resistance prevents the caisson from rising.

  However, in the caisson described in Patent Document 2, the steel plate is pushed out from the caisson into the ground. When the ground from which the steel plate is pushed out is a strong ground such as a rock, the steel plate does not penetrate into the strong ground. . For this reason, the ground which extrudes the said steel plate is restricted to a soft ground, and even if it is a soft ground, if it does not make a steel plate thinner, it will not penetrate. Furthermore, in the caisson described in Patent Document 2, when the steel plate is thin, the attachment strength of the attachment portion between the steel plate and the caisson cannot be increased, and the magnitude of the buoyancy is equal to or greater than the attachment strength of the attachment portion. The caisson cannot be held at a predetermined depth.

  Moreover, in the caisson described in Patent Document 2, the installation of the steel sheet inside the caisson and the extrusion of the steel sheet outside the caisson are performed before the installation of the bottom plate of the caisson. For this reason, in the caisson described in Patent Document 2, an operator must perform the above-described work in an environment where ground water is filled in the caisson, and work in a diving state is required. Inferior.

  Further, in the manhole described in Patent Document 3, an anchor member is formed by projecting from the periphery of the side surface on the surface opening end side of the manhole, and the base portion of the anchor member is fixed to the tube side surface of the manhole tube and projects from the tube side surface. The part is buried in the pavement on the ground surface.

  However, in the manhole described in Patent Document 3, since there is no earth and sand above the anchor member embedded in the pavement surface, the weight of earth and sand and shear resistance of earth and sand do not act on the anchor member. For this reason, when this anchor member is used in a caisson, the pavement portion in which the anchor member is embedded cannot be resisted by the large buoyancy of groundwater, and the pavement portion in which the anchor member is embedded is peeled from the road surface, or the anchor member is pulled out from the pavement portion. Become. Therefore, the anchor member cannot hold the caisson at a predetermined depth.

  Also, to maintain the position and posture against the pressure received in the soil, large water pressure or earth pressure acts on the faceplate at the tip of the excavator when the propulsion pipe is installed during propulsion work, and the propulsion pipe row is There is a shield machine equipped with a device that prevents the backing being pushed back into the interior (for example, Patent Document 4).

  The shield machine described in Patent Document 4 is provided with a plurality of penetrating pins or friction plates configured to protrude from the outer peripheral surface by a hydraulic device on the outer periphery of the outer shell. The penetration pin or the friction plate resists the water pressure and the earth pressure so that the shield machine is not returned by being pushed out from the outer peripheral surface to the ground by a hydraulic device after excavating by one block.

  However, when the ground around the shield machine is a hard ground, the penetration pin or the friction plate does not penetrate the hard ground, or the penetration pin or the friction plate does not protrude to a predetermined position, The shield machine must be held at a predetermined position against the water pressure and earth pressure only by the friction force between the penetration pin or the friction plate and the hard ground. For this reason, when the invention described in Patent Document 4 is applied to the caisson, a larger buoyancy acts on the caisson than the propulsion pipe, so that the caisson is held at a predetermined depth only by the frictional force. Can not do it.

JP-A-8-105054 JP 2001-280056 A JP-A-8-165671 JP 2003-193792 A

  The present invention has been made in view of the above problems, and its purpose is to prevent the caisson from floating, which can keep the caisson in the ground against the buoyancy of groundwater acting on the caisson submerged in the ground. It is in providing the installation method of a member and the floating prevention member of the said caisson.

  In order to achieve the above object, the float prevention member of the first aspect of the present invention is fixed to a communication portion that communicates between the inside and the outside provided on the side wall of the caisson, and has a support member having a hole, and a hole in the support member. And a load transmission member having a proximal end side supported by the portion and a distal end side protruding into the soil outside the side wall.

  According to this aspect, since the shear resistance of the soil acts on the distal end side of the load transmitting member projected into the soil, via the support member that supports the joint portion on the proximal end side of the load transmitting member, It becomes possible to resist buoyancy acting on the caisson. Therefore, the caisson can be prevented from floating from the ground.

The float prevention member according to a second aspect of the present invention is characterized in that, in the first aspect, the load transmission member is supported by the hole portion in contact with the inside of the hole portion. And
According to this aspect, since the joint portion of the load transmission member and the hole portion of the support member are in surface contact, the load transmission member is firmly supported by the support member. For this reason, the load transmission member is supported in a cantilever state with respect to the support member. Thereby, it can be made to act on a caisson via a support member, without attenuating the shear resistance of the soil which acts on the said load transmission member.

The float prevention member according to a third aspect of the present invention is characterized in that, in the first aspect or the second aspect, the load transmission members are formed to have the same diameter.
According to this aspect, since the load transmission member is formed with the same diameter, the processing cost can be reduced and the cost can be reduced. In addition, the configuration of the load transmission member can be simplified.

  According to a fourth aspect of the present invention, the anti-floating member according to the first aspect or the second aspect is such that the joint portion is formed in a tapered shape, and the hole portion is formed in a reverse tapered shape corresponding to the tapered shape. It is characterized by.

  According to this aspect, it is possible to make the cross section of the joint portion larger than when the joint portion is formed in a cylindrical shape by forming the joint portion into a tapered shape. Thereby, the magnitude | size of the shear resistance which a load transmission member can endure can be enlarged rather than the case where a junction part is formed in a cylindrical shape. That is, when receiving the same amount of shear resistance, the load transmission member having a tapered cross section can be made smaller in diameter than the load transmission member having a cylindrical cross section.

  According to a fifth aspect of the present invention, in the first aspect or the second aspect, the anti-floating member is configured such that the load transmission member is screwed into the hole portion to restrict displacement of the load transmission member in the axial direction. It is characterized by being.

  According to this aspect, by screwing the load transmission member and the support member, the load transmission member can be reliably fixed to the support member. For this reason, when the force which goes to the caisson frame from the natural ground side acts on the cross section perpendicular to the axis of the load transmission member due to the load due to earth water pressure, the displacement of the load transmission member in the axial direction can be surely restricted.

  According to a sixth aspect of the present invention, the anti-floating member according to the first aspect or the second aspect is configured such that the load transmission member is fitted into the hole and the displacement of the load transmission member in the axial direction is restricted. It is characterized by being.

  According to this aspect, by fitting the load transmission member and the support member, the load transmission member can be reliably fixed to the support member. For this reason, when the force which goes to the caisson frame from the natural ground side acts on the cross section perpendicular to the axis of the load transmission member due to the load due to earth water pressure, the displacement of the load transmission member in the axial direction can be surely restricted.

The float prevention member according to a seventh aspect of the present invention is characterized in that, in any one of the first to fourth aspects, an excavation member is provided at a tip of the load transmission member.
According to this aspect, the installation process of the anti-floating member can be reduced by providing the load transmitting member with the excavating member. The excavation member includes a bit, a chip, and the like.

  According to an eighth aspect of the present invention, in the seventh aspect, the anti-floating member according to the seventh aspect is configured such that the excavation member has a diameter of a cutting edge circle formed by the excavation member that is larger than an outer diameter of the tip side of the load transmission member. It is characterized by that.

  According to this aspect, since the diameter of the cutting edge circle formed by the excavation member is larger than the outer diameter on the tip side of the load transmission member, the outer peripheral surface of the load transmission member and the ground around the outer peripheral surface of the load transmission member And the force required for excavation of the load transmission member can be reduced.

  According to a ninth aspect of the present invention, in the first, second, or fourth aspect, the anti-floating member includes an excavation member at a tip of the load transmission member, and an agitation unit on the outer periphery of the load transmission member. It is characterized by that.

  According to this aspect, the load transmission member is disposed in the excavated hole, and the grout material is agitated by the agitating means while or after injecting the grout material into the excavation hole, thereby surrounding the load transmission member. The mountain soil and the grout material can be mixed and stirred, and the layer of the grout material solidified around the load transmission member can be integrated with the load transmission member. Thereby, the diameter of a floating prevention member can be enlarged and the shearing resistance which acts on a load transmission member can be enlarged. As a result, it is possible to reduce the number of load transmission members, and hence the floating prevention members.

According to a tenth aspect of the present invention, in the ninth aspect, the anti-floating member according to the ninth aspect is such that the stirring means is a fixed protrusion, and the diameter of the cutting edge circle formed by the protrusion is smaller than the inner diameter of the hole. Features.
According to this aspect, in addition to the same effect as the ninth aspect, the tip end side of the load transmitting member can be made thinner than the hole, and the cost can be reduced.

According to an eleventh aspect of the present invention, in the ninth aspect, the anti-floating member is characterized in that the excavation member can be turned upside down, and an outer diameter formed in a fallen state is smaller than an inner diameter of the hole.
According to this aspect, since the excavation member is configured to be inverted, a hole having a diameter larger than the inner diameter of the hole is excavated in the soil by standing the excavation member after passing the hole in the tilted state. can do. Thus, by grinding and solidifying the grout material after excavation, a layer of grout material larger than the inner diameter of the hole can be formed around the load transmission member, and the shear resistance acting on the load transmission member can be increased. .

According to a twelfth aspect of the present invention, in the eleventh aspect, the anti-floating member is characterized in that the stirring means can be inverted, and the outer diameter formed in the collapsed state is smaller than the inner diameter of the hole.
According to this aspect, in addition to the same effect as the eleventh aspect, the grout material around the load transmitting member and the grout material are mixed and stirred by stirring the grout material with the stirring means standing. The grout material layer solidified around the load transmission member can be integrated with the load transmission member. Thereby, the diameter of a floating prevention member can be enlarged and the shearing resistance which acts on a load transmission member can be enlarged. As a result, the number of load transmission members can be reduced. In addition, since the size of the hole opening in the segment can be reduced, the reinforcement around the hole of the segment opening can be reduced in scale.

  According to a thirteenth aspect of the present invention, in the floating prevention member according to any one of the first to fourth aspects, the load transmission member is a cylindrical body and is formed in the soil so that the load transmission member protrudes. The hole to be formed is cylindrical.

  According to this aspect, since the amount of soil to be excavated for projecting the load transmission member into the ground can be reduced, the excavation time can be shortened and the influence on the surrounding natural ground is minimized. Can be.

According to a fourteenth aspect of the present invention, the float prevention member according to any one of the first to thirteenth aspects includes a lid fixed to the inside of the side wall by a coupling means, and the lid is configured to transmit the load. The displacement of the member in the axial direction is restricted.
According to this aspect, the displacement of the load transmitting member in the axial direction can be reliably regulated by attaching the lid to the inside of the side wall of the caisson.

  According to a fifteenth aspect of the present invention, in the float prevention member according to any one of the first to fourteenth aspects, a drainage groove extending along an axial direction of the hole is formed in the hole of the support member. It is characterized by being.

  According to this aspect, by providing the drainage groove on the support member, the excavated earth and sand generated during excavation can be discharged through the drainage groove, and the workability of the excavation work can be improved. In addition, when the support member is contacted to support the joint portion, the adhering mud of the support member can be removed from the contact surface between the support member and the joint portion through the drainage groove so that the support member and the joint portion are brought into close contact with each other. be able to.

  According to a sixteenth aspect of the present invention, in the first aspect, the float prevention member includes a male screw formed on an outer periphery of the load transmission member, a female screw formed on the hole, and an excavation member disposed on a tip of the load transmission member. And the load transmitting member is screwed into the hole, the soil is excavated by the excavating member, and the load transmitting member is protruded into the soil.

  According to this aspect, it is not necessary to excavate an excavation hole for projecting the load transmission member in advance, and the load transmission member can be disposed in the ground simply by screwing the load transmission member with respect to the support member. it can. For this reason, in this aspect, since drilling water is not required, the natural ground around the load transmission member is not disturbed. For this reason, the load transmission member of this aspect can bite into a natural ground firmly, and can increase load transmission force.

According to a seventeenth aspect of the present invention, in the sixteenth aspect, the anti-floating member is characterized in that the excavating member is configured to guide the excavated soil into the load transmitting member.
According to this aspect, since the excavated soil is accommodated in the load transmitting member, it is not necessary to discharge the excavated soil to the outside. For this reason, it is not necessary to make the apparatus for construction large, and construction cost can be reduced.

According to an eighteenth aspect of the present invention, in the sixteenth aspect or the seventeenth aspect, the float prevention member is a valve capable of injecting a grout material into the joint from the inside of the side wall toward the inside of the load transmission member. It is characterized by providing.
According to this aspect, the strength of the load transmitting member can be improved by storing the excavated soil inside the load transmitting member and injecting and solidifying the grout material.

According to a nineteenth aspect of the present invention, there is provided a method of installing the anti-floating member from the side wall through the hole of the support member having a hole, which is fixed to a communication portion that communicates between the inside and outside of the caisson. Excavating a hole in the soil for projecting the load transmitting member toward the ground outside the side wall;
The method includes a step of inserting the load transmission member into a hole in the excavated soil and a step of supporting and fixing the joint portion of the load transmission member in the hole.

  According to this aspect, since the load transmitting member is provided in the caisson side wall so as to protrude into the soil, the load transmitting member receives shear resistance of the earth and sand. Therefore, the shear resistance can maintain the caisson at a predetermined depth against buoyancy acting on the caisson.

  According to a twentieth aspect of the present invention, there is provided a method of installing the anti-floating member from the side wall through the hole of the support member having a hole, which is fixed to the communication portion that communicates the inside and outside of the caisson. Excavating a hole in the soil for projecting the load transmitting member toward the ground outside the side wall and projecting the load transmitting member into the excavated soil hole; and And supporting and fixing the joint portion of the load transmitting member.

  According to this aspect, by providing the excavation member at the tip of the load transmission member, there is no need to excavate a hole for projecting the load transmission member in advance, and the step of excavating the hole and the step of projecting the load transmission member, Can be performed in one step. Thereby, the construction period can be shortened.

According to a twenty-first aspect of the present invention, in the nineteenth or twentieth aspect, the float prevention member installation method includes a step of injecting a grout material into the excavated hole through the load transmission member. To do.
According to this aspect, by injecting the grout material into the excavation hole in which the load transmission member is arranged, the grout material is solidified in the excavation hole, so that the load transmission member is reliably fixed to the ground. Can be.

  According to a twenty-second aspect of the present invention, in the twenty-first aspect, the float prevention member is installed by rotating the load transmission member so that the injected grout material and ground soil around the load transmission member are And a step of solidifying the stirred grout material.

  According to this aspect, by mixing and stirring the injected grout material with the soil of the surrounding ground around the load transmission member, the strength of the grout layer formed around the load transmission member is improved and the load is increased. The transmission member can be securely fixed to the ground.

  According to a twenty-third aspect of the present invention, there is provided the method of installing the anti-floating member, wherein the load transmission is performed via the hole portion of the support member having a hole portion, which is fixed to the communication portion that communicates between the inside and the outside of the caisson. A step of digging an inner tube member, which is disposed inside the member and having a digging member at a tip thereof, into the soil outside the side wall together with the load transmission member to project the load transmission member; and It includes a step of pulling out the protruding load transmission member and a step of supporting and fixing the joint portion of the load transmission member in the hole.

  According to this aspect, the process of excavating the hole for projecting the load transmitting member into the soil and the process of projecting the load transmitting member into the hole can be performed as one process. Further, since the hole is excavated as a cylindrical hole, the amount of earth and sand to be excavated can be reduced, and the excavation time can be shortened. Furthermore, since the extra excavation outside the load transmission member can be reduced, it is possible to reduce the disturbance of the natural ground around the load transmission member.

According to a twenty-fourth aspect of the present invention, in the twenty-third aspect, there is provided a method of installing a float prevention member, the step of injecting a grout material into the excavated hole through the load transmitting member, and the injected grout material. And a solidifying step.
According to this aspect, it is possible to enhance the connectivity between the load transmission member and the ground around the load transmission member by injecting and solidifying the grout material.

According to a twenty-fifth aspect of the present invention, in the first to twenty-fourth aspects, the method for installing a floating prevention member includes a step of attaching a lid to the inside of the side wall using a coupling means. To do.
According to this aspect, since the position of the joint portion of the load transmission member can be defined with respect to the inside of the caisson side wall by the lid, displacement of the load transmission member in the axial direction can be restricted. Further, the lid can prevent the intrusion of groundwater due to the pressure from the outside of the caisson. Moreover, it can prevent that the end surface of the junction part of a load transmission member touches external air with a cover body, and can prevent corrosion of the end surface of this junction part.

  According to a twenty-sixth aspect of the present invention, there is provided a method for installing the anti-floating member comprising: a load transmitting member that is fixed to a communication portion that communicates between the inside and the outside provided on the side wall of the caisson; And a step of excavating the soil by screwing it with respect to the hole, and a step of guiding the excavated soil into the load transmitting member and causing the load transmitting member to protrude into the soil. To do.

  According to this aspect, the step of excavating a hole for projecting the load transmitting member into the soil and the step of projecting the load transmitting member into the hole by simply screwing the load transmitting member with respect to the support member are performed in one step. The construction cost can be reduced because a water stop device is not required for the construction.

According to a twenty-seventh aspect of the twenty-seventh aspect of the present invention, in the twenty-sixth aspect, the method for installing a float prevention member includes a step of injecting a grout material into the load transmitting member and a step of solidifying the injected grout material. It is characterized by that.
According to this aspect, the strength of the load transmission member is increased by injecting a grout material into the load transmission member and mixing and solidifying with the excavated soil accommodated in the load transmission member. Can do.

The side sectional view of a caisson provided with the anti-floating member concerning the 1st example of the present invention. The perspective view of the housing in the middle of settling in a caisson provided with the floating prevention member which concerns on a 1st Example. The perspective view of the housing after sunk in a caisson provided with the floating prevention member which concerns on a 1st Example. The schematic diagram of the shear resistance of the earth and sand which acts on a floating prevention member. (A) is the schematic diagram which looked at the floating prevention member shown in FIG. 4 from the Y-axis direction in FIG. 4, (B) is the schematic diagram which looked at the floating prevention member shown in FIG. 6 from the X-axis direction in FIG. Figure. The perspective view of the segment which comprises the caisson provided with the floating prevention member which concerns on a 1st Example. (A) is a perspective view of the supporting member of the floating prevention member which concerns on a 1st Example, (B) is a perspective view of the load transmission member of the floating prevention member which concerns on a 1st Example. (A) is a perspective view of the location where the anti-floating member is installed in the segment in the first embodiment, and (B) is a side sectional view of the location where the anti-floating member is installed in the segment in the first embodiment. The perspective view which shows the state which made the load transmission member protrude in the soil in the floating prevention member installation location of the segment in 1st Example (A) is a perspective view of a lid that defines the position of the load transmission member in the axial direction relative to the inside of the segment, and (B) is a perspective view showing a state in which the position of the load transmission member is defined by the lid in FIG. 9. Figure. (A) is a sectional side view which shows the 1st process of the installation method of the floating prevention member based on 1st Example, (B) is a sectional side view which shows a 2nd process. (A) is a sectional side view which shows the 3rd process of the installation method of the floating prevention member based on 1st Example, (B) is a sectional side view which shows a 4th process. (A) is a sectional side view which shows the 5th process of the installation method of the floating prevention member based on 1st Example, (B) is a sectional side view which shows a 6th process. (A) is a sectional side view which shows the 7th process of the installation method of the floating prevention member based on 1st Example, (B) is a sectional side view which shows an 8th process. (A) is a sectional side view showing a ninth step of the installation method of the anti-floating member according to the first embodiment, and (B) is a sectional side view showing the tenth step. (A) is a sectional side view which shows the 11th process of the installation method of the floating prevention member based on 1st Example, (B) is a sectional side view which shows a 12th process. (A) is a perspective view of a flange member attached to the inner wall of a segment for attaching a water stop device, and (B) is a protrusion that projects the load transmission member into the soil by pressing the rear end of the load transmission member. The perspective view of a stick | rod. (A) is a perspective view of the 1st modification of the load transmission member which concerns on 1st Example, (B) is a perspective view of the 2nd modification of the load transmission member which concerns on 1st Example. (A) is a perspective view of the 3rd modification of the load transmission member which concerns on 1st Example, (B) is a perspective view of the support member corresponding to the load transmission member of a 3rd modification. The perspective view of the example of a change of the supporting member which concerns on a 1st Example. (A) is a perspective view of the support member of the floating prevention member which concerns on a 2nd Example, (B) is a perspective view of the load transmission member of the floating prevention member which concerns on a 2nd Example. (A) is a perspective view of the location where the anti-floating member is installed in the segment in the second embodiment, and (B) is a side sectional view of the location where the anti-floating member is installed in the segment in the second embodiment. (A) is a sectional side view which shows the last process of the installation method of the floating prevention member which concerns on a 2nd Example, (B) is a perspective view which shows the example of a change of the supporting member which concerns on a 2nd Example. (A) is a perspective view of the support member of the floating prevention member which concerns on a 3rd Example, (B) is a perspective view of the load transmission member of the floating prevention member which concerns on a 3rd Example. (A) is a perspective view of the support member of the floating prevention member which concerns on a 4th Example, (B) is a perspective view of the load transmission member of the floating prevention member which concerns on a 4th Example. The perspective view of the protrusion corresponding to the load transmission member in a 4th Example. (A) is a sectional side view which shows the 1st process of the installation method of the floating prevention member which concerns on a 4th Example, (B) is a sectional side view which shows a 2nd process. (A) is a sectional side view which shows the 3rd process of the installation method of the floating prevention member which concerns on a 4th Example, (B) is a sectional side view which shows a 4th process. (A) is a sectional side view which shows the 5th process of the installation method of the floating prevention member which concerns on a 4th Example, (B) is a sectional side view which shows a 6th process. (A) is a sectional side view which shows the 7th process of the installation method of the floating prevention member which concerns on a 4th Example, (B) is a sectional side view which shows an 8th process. (A) is a sectional side view which shows the 9th process of the installation method of the floating prevention member which concerns on a 4th Example, (B) is a sectional side view which shows a 10th process. (A) is a perspective view of the 1st modification of the load transmission member which concerns on a 4th Example, (B) is a perspective view of the 2nd modification of the load transmission member which concerns on a 4th Example. (A) is a perspective view of the load transmission member of the anti-floating member according to the fifth embodiment, and (B) is a side sectional view showing the seventh step of the method of installing the anti-floating member according to the fifth embodiment. Figure. (A) is a perspective view which shows the state which opened the stirring means in the load transmission member of the floating prevention member which concerns on a 6th Example, (B) is a load transmission member of the floating prevention member which concerns on a 6th Example The perspective view which shows the state which closed the stirring means in FIG. (A) is an open / close state explanatory drawing of the excavation member in the load transmission member of the float prevention member according to the sixth embodiment, and (B)) is agitation in the load transmission member of the float prevention member according to the sixth embodiment. Opening / closing state explanatory drawing of a means. (A) is a perspective view of the load transmission member of the floating preventing member according to the seventh embodiment, and (B) is a perspective view of the inner tube member according to the seventh embodiment. (A) It is a perspective view which shows the state which combined the load transmission member and inner pipe member which concern on a 7th Example, (B) is a sectional side view in the state of (A). (A) is a sectional side view which shows the 1st process of the installation method of the floating prevention member which concerns on a 7th Example, (B) is a sectional side view which shows a 2nd process. (A) is a sectional side view which shows the 3rd process of the installation method of the floating prevention member which concerns on a 7th Example, (B) is a sectional side view which shows a 4th process. (A) is a sectional side view which shows the 5th process of the installation method of the floating prevention member which concerns on a 7th Example, (B) is a sectional side view which shows a 6th process. (A) is a front side perspective view of the load transmission member of the float prevention member according to the eighth embodiment, and (B) is a rear perspective view of the load transmission member of the float prevention member according to the eighth embodiment. (A) is a sectional side view showing the 1st process of the installation method of the floating prevention member concerning the 8th example, and (B) is a sectional side view showing the 2nd process. (A) is a sectional side view which shows the 3rd process of the installation method of the floating prevention member which concerns on an 8th Example, (B) is a sectional side view which shows a 4th process. (A) is a back side perspective view of the example of a change of the load transmission member of the float prevention member concerning an 8th example, and (B) is a modification of the load transmission member of a float prevention member concerning an 8th example. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure in each Example, the same code | symbol is attached | subjected and it demonstrates only in the first Example, The description of the structure is abbreviate | omitted in a subsequent Example.

<About caisson structure>
Referring to FIG. 1, a caisson 12 including a float prevention member 10 according to the present invention is shown. The caisson 12 includes a caisson body 16 that is submerged in the ground from the ground surface 14, a plurality of anti-floating members 10 that protrude from the side walls 18 of the caisson body toward the ground outside the caisson body 16, and the caisson body 16. And a bottom plate 20 provided at the bottom of the base plate.

  The caisson body 16 is configured by stacking a plurality of housings 22 as shown in FIG. In this embodiment, the housing 22 is configured as a ring-shaped member by joining a plurality of segments 24 described later.

  After the caisson 12 has been installed, the bottom plate 20 (underwater concrete) (see FIG. 1) is placed, and after the water in the caisson body 16 is pumped up, the caisson body 16 and the outer ground are formed from the caisson body 16. The mortar (not shown) is grouting from a grout hole (not shown) provided in the segment 24 to fill the gap between the frame 22 and the ground, thereby bringing the cabinet 22 into close contact with the ground and preventing ground subsidence. it can.

  Further, as shown in FIG. 1, after placing the bottom plate 20 on the bottom of the caisson body 16, a plurality of floating prevention members 10 in the caisson body 16 from the side wall 18 of the caisson body 16 toward the soil outside the side wall 18. Is projected.

FIG. 3 shows the vicinity of the bottom of the caisson body 16. A plurality of floating prevention members 10 in the vicinity of the bottom of the caisson body 16 are provided with a plurality of floating prevention members 10 so as to protrude from the housing 22 toward the ground outside the housing 22. In the illustrated example, the anti-floating member 10 extends toward the outside of the segment 24 through a hole portion 28 of a support member 26 provided in the segment 24 described later. Further, the floating prevention members 10 are arranged in a staggered manner on the plurality of stages of the casings 22 along the caisson main body 16 setting direction.

  Here, as shown in FIG. 3, the caisson body 16 submerged in the ground has a bottom plate 20 that has a buoyancy σ so as to lift the caisson body 16 from the groundwater contained in the soil in which the caisson body 16 is submerged. (See FIG. 1). Therefore, a reaction force F acts on the caisson body 16 via the plurality of anti-floating members 10 in order to hold the caisson body at a predetermined depth against the buoyancy σ.

  The reaction force F that holds the caisson body 16 at a predetermined depth against the buoyancy σ will be described in detail with reference to FIGS. 4, 5 </ b> A, and 5 </ b> B. The reaction force F is described in detail below, but is based on the shear resistance τ of earth and sand.

  Here, FIG. 4 is a schematic diagram showing the relationship between the buoyancy acting on the floating prevention member and the caisson body 16 and the shear resistance τ of earth and sand when the floating prevention member 10 exists in the ground. In FIG. 4, buoyancy σ acts on the floating prevention member 10 from below in the Z direction. Sediment shear resistance τ acts on the anti-floating member 10 against the buoyancy σ from diagonally above in the Z-axis direction. The shear resistance τ of earth and sand is obtained from the following equation (1) with reference to FIGS. 5 (A) and 5 (B).

        τ = C + σ tan θ (1)

Here, τ is shear resistance (KN / m ² ) of earth and sand, C is adhesive force (KN / m ² ), θ is a shear resistance angle or internal friction angle, and tan θ is a friction coefficient.

  That is, as shown in FIGS. 4, 5A, and 5B, the shear resistance τ of earth and sand is inclined at an angle θ with respect to the Z-axis direction from the floating preventing member 10 to the floating preventing member 10. The force acting on the anti-floating member 10 at each of the four inclined surfaces 30 extending upward. Therefore, this force acts on the floating prevention member 10 so as to resist the buoyancy σ acting on the floating prevention member 10, and prevents the floating prevention member 10 from being lifted by the buoyancy σ.

  Referring again to FIG. 3, the anti-floating member 10 is fixed via a support member 26 (described later) provided on the side wall 18 of the caisson body 16. For this reason, each of the anti-floating members 10 protruding from the side wall 18 of the caisson main body 16 includes a total of three surfaces: two surfaces located on both sides of the anti-floating member 10 and one surface located on the tip side of the anti-floating member 10. A shear resistance τ acts on the inclined surface 30.

Therefore, the caisson body 16 has a total shear resistance nτ (KN / m ² ) obtained by multiplying the shear resistance τ acting on one float prevention member 10 by the number n of the float prevention members 10 provided on the caisson body 16. Will act. In the example of FIG. 3, the number of the anti-floating members 10 shown in the figure is nine, so that a shear resistance of at least 9τ (KN / m ² ) acts on the caisson body 16.

Further, a force having a magnitude of τ (KN / m ² ) acts on each floating prevention member 10 in the caisson main body 16 setting direction, that is, in the −Z direction. Accordingly, a reaction force F having a magnitude of nτ (KN / m ² ) acts on the caisson body 16. Further, the magnitude of the reaction force F can be adjusted by increasing or decreasing the number n of the anti-floating members 10 provided in the caisson body 16. For this reason, since the caisson 12 adjusts the reaction force F against the buoyancy σ by the number n of the anti-floating members 10, it is not necessary to increase the weight of the caisson body 16. Therefore, by increasing the number n of the anti-floating members 10, the weight of the housing 22 can be reduced, and the cost can be reduced.

  Further, as will be described later, since the anti-floating member 10 is provided after the bottom plate 20 of the caisson body 16 is installed, the installation work of the anti-floating member 10 is easy, and the number n of the anti-floating members 10 provided on the caisson body 16 It is easy to increase. Therefore, even when the buoyancy σ acting on the caisson body 16 increases due to an increase in groundwater in the soil in the vicinity where the caisson 12 is installed, the anti-floating member 10 can be added after the caisson 12 is completed. Can be easily prevented from floating.

  Furthermore, by setting the frame 22 on which the anti-floating member 10 is provided to a predetermined depth, that is, a depth of 20 m or more, the anti-floating member 10 is provided on a strong ground such as a rock layer, which is caused by an earthquake. There is no risk of being affected by liquefaction, or there is little fear. For this reason, the float prevention member 10 can hold the caisson 12 at a predetermined depth.

  Next, the segment 24 in this embodiment will be described with reference to FIG. The segment 24 is an arc-shaped structure obtained by dividing a circle as shown in FIG. 6, and is formed of a steel material or the like. The material of the segment 24 includes reinforced concrete, composite, etc. in addition to steel (steel).

  The segment 24 includes a skin plate 32, main girders 34 and 34 disposed on the upper and lower ends of the skin plate 32, joint plates 36 and 36 disposed on the sides of the skin plate 32, and the segment 24. A plurality of ribs 38a that reinforce and extend in the vertical direction, a plurality of ribs 38b that reinforce the segment 24 and extend in the circumferential direction, and a reinforcing plate 40 that is disposed inside the skin plate 32 and joined to the ribs 38a and 38b. A communication portion 41 provided through the reinforcement plate 40 and communicating between the inside and outside of the side wall 18 of the caisson main body 16; a support member 26 described later fixed to the communication portion 41; and a support member in the reinforcement plate 40 26 and a plurality of bolt holes 42 provided around 26.

  The segment 24 is a steel segment in this embodiment. When the anti-floating member 10 is attached to the side wall 18 of the caisson 12, the attachment portion is required to have sufficient strength. Therefore, it is necessary to reinforce the periphery of the support member 26 in order to attach the support member 26 described later to the segment 24. The reinforcing plate 40 plays a reinforcing role for supporting the support member 26. Furthermore, attaching the flange member 56 (refer FIG. 17 (A)) mentioned later to the reinforcement board 40 is also performed.

  The segments 24 are connected to adjacent segments 24 by connecting means such as bolts, and the plurality of segments 24 are connected to form a cylindrical housing 22. Further, referring to FIG. 2 again, the plurality of housings 22 stacked in the vertical direction of the page in FIG. 2, that is, in the direction in which the caisson body 16 is set, are arranged so that the segments 24 constituting the housing 22 are displaced in the circumferential direction. It is connected so that it may be arranged in a shape. For this reason, the support members 26 of the floating prevention member 10 described later are also arranged in a staggered manner in the circumferential direction along the caisson body 16 settling direction.

<<<< first embodiment >>
Next, with reference to FIG. 7A and FIG. 7B, the configuration and attachment state of the anti-floating member 10 according to the first embodiment will be described. The floating prevention member 10 includes a support member 26 and a load transmission member 44. In this embodiment, the support member 26 is formed as a cylindrical member having a hole portion 28 penetrating along the axial direction.

  The load transmission member 44 includes a distal end side 44a and a joint portion 44b provided on the proximal end side. In the present embodiment, the distal end side 44a and the joint portion 44b are configured with the same diameter. The load transmission member 44 includes a through hole 46 that penetrates the load transmission member 44 along the axial direction. The outer diameter of the joint 44b is set to be the same as the inner diameter of the hole 28 of the support member 26. That is, the joint portion 44b can be fitted into the hole portion 28 without a gap.

  As shown in FIGS. 8A and 8B, the support member 26 is attached to the communication portion 41 of the segment 24. One end portion 26 a of the support member 26 is in contact with the skin plate 32. The other end 26 b is exposed toward the space inside the caisson 12. That is, the support member 26 and thus the axis of the hole 28 intersect the skin plate 32. For this reason, the end portion 26 a side of the hole portion 28 of the support member 26 is closed by the skin plate 32. Thereby, when the caisson 12 is laid, the groundwater outside the caisson 12 does not flow into the caisson 12 through the hole 28 of the support member 26.

  Next, a state in which the load transmission member 44 is protruded from the side wall 18 of the caisson 12 will be described with reference to FIGS. 9, 10 </ b> A, and 10 </ b> B. The tip end side 44 a of the load transmission member 44 projects into the soil outside the side wall 18 of the caisson 12 through the hole 28 of the support member 26. At this time, the skin plate 32 positioned outside the support member 26 is drilled by a drilling cutter 48 described later at a position corresponding to the hole 28.

  Further, the joint portion 44 b is fitted into the hole portion 28 without a gap, and is supported by the support member 26. Further, referring to FIG. 10 (A), a disc-shaped lid 50 is shown. The lid 50 is provided with a plurality of through holes 52 at intervals in the circumferential direction. The plurality of through holes 52 in the lid 50 are provided at positions corresponding to the plurality of bolt holes 42 provided in the reinforcing plate 40 to which the support member 26 is attached when the lid 50 is attached to the reinforcing plate 40. ing.

  Referring to FIG. 10B, the lid 50 is attached to the reinforcing plate 40 by screwing a plurality of bolts 54 into the bolt holes 42 through the through holes 52. As a result, the joint 44b, that is, the load transmission member 44, is restricted from being displaced toward the inside of the caisson 12 in the axial direction. For this reason, the load transmitting member 44 is fixed to the side wall 18 of the caisson 12 in a cantilever state.

  Therefore, when the earth and sand shearing resistance τ acts on the tip end side 44 a of the load transmitting member 44, the shearing resistance τ acts on the caisson body 16 reliably through the joint 44 b and the support member 26.

  In addition, by attaching the lid 50 to the reinforcing plate 40, it is possible to prevent infiltration of groundwater due to pressure from the outside of the caisson 12 toward the inner wall side of the caisson main body 16. In this case, the water stoppage can be improved by disposing an elastic waterstop material such as an O-ring or a rubber member (not shown) between the lid 50 and the reinforcing plate 40. Further, in this embodiment, an oil or grease agent such as grease is applied to one side 50a of the lid 50, that is, the side that contacts the load transmission member 44 and the support member 26. Thereby, it can prevent or suppress that the end surface of the junction part 44b and the other end part 26b of the supporting member 26 corrode by the ground water in the soil in which the caisson 12 is sunk, or by touching the outside air. Can do.

<Installation process of the anti-floating member according to the first embodiment>
Next, with reference to FIG. 11 (A) to FIG. 17 (B), a method of installing the anti-floating member 10 according to the first embodiment will be described. FIG. 11A shows a state in which the groundwater stored inside the caisson main body 16 is drained after the bottom plate 20 is placed in the caisson 12.

  As a first step, in FIG. 11B, a flange member 56 (FIG. 17) is attached to the support member 26 fixed to the communicating portion 41 of the segment 24 constituting the side wall 18 of the caisson main body 16 via the reinforcing plate 40. (Refer to (A)) with bolts 54. Here, the flange member 56 will be described with reference to FIG.

  The flange member 56 is formed as a tubular member, and one end 56a thereof is formed in a flange shape. A plurality of through holes 58 are provided in the flange-shaped one end portion 56 a so as to correspond to the positions of the bolt holes 42 of the reinforcing plate 40. A female screw 60 is formed on the inner peripheral surface of the other end 56b. The flange member 56 has a flange-shaped end portion 56 a attached to the reinforcing plate 40, that is, the side wall 18 by a plurality of bolts 54 that are screwed into the bolt hole 42 via the through holes 58, and is firmly fixed to the side wall 18. .

  Next, as a second step, as shown in FIG. 12A, the water stop device 62 is attached to the other end portion 56 b of the flange member 56. The water stop device 62 includes a hollow pipe 64, a first partition valve 68 attached in order from the distal end side 66 (left side of FIG. 12A) of the hollow pipe 64, an injection valve 70, and an exhaust mud. A valve 72, a second partition valve 74, and a gland packing 76 are provided.

  The water stop device 62 is positioned between the first partition valve 68 and the injection valve 70 and the drainage valve 72, and the injection valve 70, the drainage valve 72, and the second partition valve 74 are the first partition. The valve 68 is configured to be removable. The detachable structure is a known structure and is not limited to a specific structure, and thus detailed illustration thereof is omitted.

  A male screw is formed on the distal end side 66 of the hollow pipe 64. The water stop device 62 is attached to the side wall 18 via the flange member 56 by screwing the male screw of the hollow pipe 64 with the female screw 60 of the flange member 56. In FIG. 12B, the first partition valve 68, the injection valve 70, the mud discharge valve 72, and the second partition valve 74 are in a closed state.

  As a third step, as shown in FIG. 12B, the second partition valve 74 is opened, and the excavation cutter 48 driven by a drive source (not shown) from the rear end portion 78 side of the hollow pipe 64 is placed in the hollow pipe 64. Insert into.

  As a fourth step, as shown in FIG. 13A, the first gate valve 68 and the mud discharge valve 72 are opened, and the excavation cutter 48 is advanced into the hole 28 of the support member 26. Then, the skin plate 32 that closes the hole portion 28 of the support member 26 is excavated by the excavation cutter 48, and the hole portion 28 is opened toward the outside of the side wall 18 of the caisson 12.

  At this time, water is supplied from the water stop device 62 to the tip of the excavation cutter 48 from the gland packing 76 of the hollow pipe 64 to the tip of the excavation cutter 48, and the excavation cutter 48 removes the processing waste of the skin plate 32. Then, water is discharged from the mud discharge valve 72 together with the processing waste. The gland packing 76 is in contact with the outer peripheral surface of the excavation cutter 48 and prevents the water from being ejected toward the rear end portion 78 of the hollow pipe 64.

  As a fifth step, as shown in FIG. 13B, the excavation cutter 48 is advanced from the opening 80 formed by the excavation cutter 48 to the natural ground UG outside the side wall 18 to excavate the natural ground UG. The excavation hole 82 extending from the side wall 18 to the natural ground UG is provided. The drilling water is fed into the hollow pipe 64 and flows from the excavation cutter 48 between the hollow pipe 64 and the natural ground in the direction of the rear end portion 78, and is thus discharged. The diameter is set to be smaller than the diameter of the hole 28 of the support member 26 as much as possible.

  At this time, water is supplied from the tip of the excavation cutter 48 to the tip side of the gland packing 76 of the hollow pipe 64, and the earth and sand excavated from the natural ground UG by the excavation cutter 48 is removed. Then, the water is discharged from the mud discharge valve 72 together with the earth and sand.

  Then, as a sixth step, the excavation cutter 48 is provided with the excavation hole 82 in the natural ground UG outside the side wall 18 and then pulled back to the rear end 78 side, and the first partition valve 68 and the mud discharge valve 72. And the 2nd gate valve 74 is closed. Thereafter, the excavation cutter 48 is removed from the hollow pipe 64.

  As a seventh step, as shown in FIG. 14A, the second gate valve 74 is opened, and the load transmitting member 44 is inserted into the hollow pipe 64 from the rear end portion 78 side of the hollow pipe 64. In addition, an insertion protrusion 84 that pushes the load transmission member 44 is disposed on the joint portion 44 b side of the load transmission member 44. As shown in FIG. 17A, the insertion protrusion 84 has a fitting portion 84 a that fits the through hole 46 of the load transmission member 44 at the tip, and the load transmission member 44 along the inner surface of the hollow pipe 64. And a guiding portion 84b for guiding.

  As an eighth step, as shown in FIG. 14B, the first gate valve 68 is opened, and the load transmitting member 44 is pushed into the excavation hole 82 by the insertion protrusion 84. At that time, the position of the joint portion 44 b and the position of the support member 26 are made to coincide with each other in the axial direction of the load transmitting member 44. That is, the load transmitting member 44 is pushed into the excavation hole 82 so that the joint portion 44b and the support member 26 are fitted. Thereafter, the insertion protrusion 84 is pulled back to the rear end 78 side of the hollow pipe 64, and the second partition valve 74 is closed.

  As a ninth step, the injection valve 70 is opened, mortar 86 as “grouting material” is injected into the excavation hole 82 through the through hole 46 of the load transmission member 44, and the mortar 86 is injected into the excavation hole 82. Fill. After injecting the mortar 86, the first gate valve 68 and the injection valve 70 are closed as shown in FIG.

  As a tenth step, as shown in FIG. 15B, the injection valve 70, the mud discharge valve 72 and the second partition valve 74 of the water stop device 62 are removed from the first partition valve 68. In the eleventh step, as shown in FIG. 16A, after the mortar 86 filled in the excavation hole 82 is solidified, the first gate valve 68 is removed from the flange member 56.

  As a twelfth step, as shown in FIG. 16B, the rear end of the load transmission member 44 (joint portion 44 b), the other end portion 26 b of the support member 26, and the reinforcing plate 40 in the axial direction of the load transmission member 44. A part of the solidified mortar 86 is removed so that the surfaces are at the same position. Then, the lid 50 is attached to the reinforcing plate 40 with bolts 54. Accordingly, the load transmission member 44 is firmly fixed to the side wall 18 of the caisson main body 16 via the support member 26 in a state where displacement of the load transmission member 44 in the axial direction is restricted. That is, the tip end side 44 a of the load transmitting member 44 is in a state of protruding from the side wall 18 of the caisson body 16.

  Furthermore, the load transmitting member 44 has sufficient strength because the mortar 86 is filled between the distal end side 44a and the excavation hole 82 and between the distal end side 44a and the opening 80.

  For this reason, the floating prevention member 10 is less likely to be damaged or less likely to be damaged when the floating prevention member 10 is bent with respect to the side wall 18 of the caisson body 16 by the action of the buoyancy σ. Accordingly, the anti-floating member 10 can withstand the shear resistance of the earth and sand acting on the anti-floating member and the weight of the earth and sand, so that the caisson main body 16 has a predetermined depth against the buoyancy σ acting on the caisson main body 16. Can be maintained.

<<< Modification of the first embodiment >>>
(1) In the present embodiment, the tip end side 44a of the load transmission member 44 and the joint portion 44b are configured to have the same diameter, but instead of this configuration, as shown in FIG. The diameter dimension of the tip end side 88a may be smaller than the diameter dimension of the joint portion 88b.
(2) Furthermore, the load transmission member 90 may be configured to include an inclined portion 90c that smoothly connects the distal end side 90a and the joint portion 90b having different diameter dimensions.

(3) In the present embodiment, the tip end side 44a of the load transmission member 44 and the joint portion 44b are configured to have the same diameter, but instead of this configuration, as shown in FIG. May be constituted by a tip end side 92a and a joining portion 92b formed in a tapered shape.

  Further, the hole portion 96 of the support member 94 may be configured to have a reverse taper shape that matches the taper gradient of the joint portion 92b so as to be fitted to the joint portion 92b of the load transmitting member 92. That is, as shown in FIG. 19B, the taper-shaped minimum diameter portion is formed on the one end portion 94a side, and the taper-shaped maximum diameter portion is formed on the other end portion 94b side. In this configuration, the support member 94 is fixed to the communication portion 41 of the segment 24 so that one end portion 94 a faces the skin plate 32 and the other end portion 94 b faces the space inside the caisson main body 16.

  By forming the joint portion 92b in a tapered shape, the cross-sectional size of the joint portion 92b can be made larger than the cross-sectional size of the cylindrical joint portion 44b. Thereby, the magnitude | size of the shearing resistance (tau) which a load transmission member can endure can be enlarged rather than the case where the junction part 92b is formed in a cylindrical shape.

(4) In the present embodiment, as shown in FIG. 20, a drainage groove 98 that communicates from one end 26a to the other end 26b of the support member 26 may be provided in the hole 28 of the support member 26. By forming the drainage groove 98 in the hole 28, the excavated earth and sand can be easily discharged at the time of drilling, and the workability of the excavation work can be improved. Furthermore, when the support member 26 and the joint portion 44b are fitted, the mud adhering to the hole portion 28 can be removed from the contact surface between the support member 26 and the joint portion 44b through the drainage groove 98, The adhesion between the member 26 and the joint portion 44b can be improved.

(5) In the present embodiment, the support member 26 and the load transmission member 44 have a circular cross-sectional shape that intersects the axial direction. It may be configured.
(6) In the present embodiment, the support member 26 is directly attached to the segment 24. However, for example, a communication hole such as a grout hole that connects the outside and the inside of the side wall 18 of the caisson body 16 to the segment 24 is provided. It is good also as a structure which provides and fixes the supporting member 26 to this communicating hole.

<<< second embodiment >>>
Next, with reference to FIG. 21 (A) to FIG. 22 (B), the configuration and attachment state of the anti-floating member 10 according to the second embodiment will be described. The float prevention member 10 according to the second embodiment includes a support member 100 and a load transmission member 102.

  As shown in FIG. 21A, the support member 100 is formed in a cylindrical shape and includes a hole 104 that penetrates along the axial direction. A female screw 106 is formed on the inner surface of the hole 104. Further, as shown in FIG. 21B, the load transmission member 102 includes a distal end side 102a and a joint portion 102b provided on the proximal end side. A male screw 108 is formed at the joint 102b. Further, in this embodiment, the diameter dimension of the distal end side 102a is set to be equal to or smaller than the diameter of the male thread valley of the joint portion 102b.

  Further, the load transmission member 102 includes a through hole 110 that penetrates the load transmission member 102 along the axial direction. On the joint portion 102b side of the through hole 110, a convex portion 116 that fits into a concave portion 114 of an insertion protrusion 112 described later is provided. Further, the load transmitting member 102 is fixed to and supported by the support member 100 when the male screw 108 of the joint portion 102 b is screwed with the female screw 106 of the support member 100.

  With reference to FIG. 22 (A) and FIG.22 (B), the attachment state to the segment 118 of the supporting member 100 is demonstrated. The segment 118 in the present embodiment is a reinforced concrete segment and is different from the segment 24 in the first embodiment in that the skin plate 32 is not provided.

  The support member 100 is attached to the communication portion 119 of the segment 118. A plurality of bolt holes 120 are provided at predetermined intervals around the support member 100 in the segment 118. Further, unlike the segment 24 of the first embodiment, the segment 118 in this embodiment does not include the skin plate 32. For this reason, when the caisson body 16 is laid down, the hole 104 of the support member 100 needs to be closed.

  For this reason, a plug 122 is attached to the hole 104 of the support member 100. The plug 122 is formed in a cylindrical shape, and a male screw that engages with the female screw 106 of the hole 104 is formed on the outer peripheral surface thereof. The plug 122 is formed of a resin material so as to be easily crushed by the excavation cutter 48.

  Further, when the caisson main body 16 constituted by the segments 118 is laid down, the hole 104 of the support member 100 is closed by the plug 122 screwed with the male screw 108. Inflow of groundwater from the soil can be prevented.

<Installation process of the anti-floating member according to the second embodiment>
Next, with reference to FIGS. 11 (A) to 16 (A), FIG. 23 (A) and FIG. 26, a method of installing the anti-floating member 10 according to the second embodiment will be described. The method of installing the anti-floating member 10 in the second embodiment is different from the method of installing the anti-floating member 10 in the first embodiment in the eighth step. Note that the first step to the seventh step and the ninth step to the twelfth step (see FIGS. 11A to 16A) are the same steps, and thus description thereof is omitted.

  The eighth step is different from the installation method according to the first embodiment (see FIG. 14B) in that the male screw of the joint portion 102b of the load transmitting member 102 is connected to the female screw 106 of the hole 104 of the support member 100. It is in screwing. The eighth step in the second embodiment will be described with reference to FIG.

  As an eighth step, the first gate valve 68 is opened, and the concave portion 114 of the insertion protrusion 112 (corresponding to 84 in the drawing) is fitted to the convex portion 116 of the load transmitting member 102 (corresponding to 44 in the drawing). Then, the load transmitting member 102 is pushed into the excavation hole 82 by the insertion protrusion 112. When the joint 102b (44b in the figure) comes into contact with the support member 100 (corresponding to 26 in the figure), the insertion protrusion 112 is rotated so that the male screw of the joint 102b is screwed into the female screw 106 of the support member 100. Thereafter, the insertion protrusion 84 is pulled back to the rear end 78 side of the hollow pipe 64, and the second partition valve 74 is closed.

  Thereafter, the ninth to twelfth steps of the installation method in the first embodiment are performed. Thereby, the load transmission member 102 is supported and fixed to the segment 118, that is, the caisson body 16 via the support member 100 as shown in FIG.

  In this embodiment, since the load transmitting member 102 is securely fixed to the support member 100 in the axial direction, the load from the natural ground side to the caisson main body 16 side by a load due to soil water pressure is applied to the cross section in the direction perpendicular to the axial line. When a force is applied in the direction, the displacement of the load transmitting member 102 in the axial direction can be reliably regulated.

  Furthermore, the load transmitting member 102 has sufficient strength because the mortar 86 is filled between the distal end side 102 a and the excavation hole 82 and between the distal end side 102 a and the opening 80.

<<< Modified Example of Second Embodiment >>>
(1) In this embodiment, as shown in FIG. 23 (B), a drainage groove 124 that communicates from one end 100a to the other end 100b of the support member 100 may be provided in the hole 104 of the support member 100. By forming the drainage groove 124 in the hole 104, the excavated earth and sand can be easily discharged during drilling, and the workability of the excavation work can be improved.

  Further, when screwing the support member 100 and the joint portion 102b, the mud adhering to the female screw 106 can be removed from the contact surface between the female screw 106 and the male screw of the joint portion 102b through the drainage groove 98. The member 100 and the joint portion 102b can be smoothly screwed together.

(2) In the present embodiment, the support member 100 is directly attached to the segment 118. For example, a communication hole such as a grout hole that connects the outside and the inside of the side wall 18 of the caisson body 16 to the segment 118 is provided. It is good also as a structure which provides and fixes the supporting member 100 to this communicating hole.
(3) In this embodiment, the plug 122 is formed of a resin material, but may be formed of a material such as iron or aluminum.

(4) In the present embodiment, the plug 122 is attached to the hole portion 104, but instead of this configuration, a temporary wall (skin plate) (not shown) is provided on the natural mountain UG side of the communication portion 119. It is good. In this configuration, the attachment of the plug 122 can be omitted.
(5) In this embodiment, the lid 50 is attached to the reinforcing plate 40. However, the lid 50 may not be attached instead of this configuration. This is because, in the load transmission member 102, since the support member 100 and the joint portion 102b are screwed together, displacement of the load transmission member 102 in the axial direction is restricted.

<<< Third embodiment >>>
Next, with reference to FIGS. 24A and 24B, the structure of the anti-floating member 10 according to the third embodiment will be described. The float prevention member 10 according to the third embodiment includes a load transmission member 126 and a support member 128.

  Further, as shown in FIG. 24A, the load transmission member 126 includes a distal end side 126a and a joint portion 126b provided on the proximal end side. Further, the load transmitting member 126 is formed with a through hole 130 penetrating along the axial direction. Further, a fitting convex portion 132 is formed on the outer peripheral surface of the joint portion 126b, and a convex portion 134 is formed on the inner peripheral surface.

  As shown in FIG. 24B, the support member 128 includes one end portion 128a and the other end portion 128b. The support member 128 is formed with a hole 136 penetrating along the axial direction. A fitting recess 138 is formed on the inner surface of the hole 136.

  The fitting recess 138 opens toward the other end portion 128 b of the support member 128, and when the load transmission member 126 is rotated relative to the support member 128 and the guide portion 138 a that guides the fitting projection 132. A fitting portion 138 b that fits with the fitting convex portion 132 and restricts the displacement of the load transmitting member 126 in the axial direction is provided.

<Installation process of the anti-floating member according to the third embodiment>
The method of installing the anti-floating member 10 in the third embodiment is different from the method of installing the anti-floating member 10 in the first embodiment in the eighth step. Note that the first step to the seventh step and the ninth step to the twelfth step (see FIGS. 11A to 16A) are the same steps, and thus description thereof is omitted.

  The eighth step is different from the installation method according to the first embodiment (see FIG. 14B) in that the load transmitting member 126 is joined to the fitting recess 138 provided in the hole 136 of the support member 128. The fitting convex part 132 of the part 126b is to be fitted. The eighth step in the third embodiment will be described with reference to FIG. As an eighth step, the first gate valve 68 is opened, and the recess 114 of the insertion protrusion 112 (corresponding to 84 in the figure) is fitted to the protrusion 134 of the load transmitting member 126 (corresponding to 44 in the figure). Then, the load transmitting member 126 is pushed into the excavation hole 82 by the insertion protrusion 112.

  At that time, in the axial direction of the load transmitting member 126, the fitting convex portion 132 on the outer peripheral surface of the joint portion 126 b is guided by the guide portion 138 a of the fitting concave portion 138 of the supporting member 128, and the supporting member 128 in the axial direction. To a predetermined position. And the fitting convex part 132 and the fitting recessed part 138 are fitted by rotating the load transmission member 126 (44 in the figure) relative to the support member 128 (corresponding to 26 in the figure). Thereafter, the insertion protrusion 84 is pulled back to the rear end 78 side of the hollow pipe 64, and the second partition valve 74 is closed.

  Then, the ninth to twelfth steps of the installation method in the first embodiment are performed. Thereby, the load transmission member 126 is supported and fixed to the caisson main body 16 via the support member 128. That is, the load transmission member 126 is supported and fixed to the support member 128 in a state where displacement in the axial direction is restricted.

<Modified example of the third embodiment>
In this embodiment, the lid 50 is attached to the reinforcing plate 40. However, instead of this configuration, the lid 50 may not be attached. This is because in the load transmission member 126, the fitting convex portion 132 and the fitting concave portion 138 are fitted, so that the displacement of the load transmission member 126 in the axial direction is restricted.

  Furthermore, the load transmission member 126 has sufficient strength because the mortar 86 is filled between the distal end side 126a and the excavation hole 82 and between the distal end side 126a and the opening 80.

<<<< Modification of the third embodiment >>>>
(1) It is good also as a structure which provides the drainage groove which connects the one end part 128a and the other end part 128b in the hole 136 of the support member 128. FIG.
(2) Also in this embodiment, the support member 128 is directly attached to the segment 24. However, for example, a communication hole such as a grout hole that connects the outer side and the inner side of the side wall 18 of the caisson body 16 to the segment 24. The support member 128 may be fixed to the communication hole.

<<< Fourth embodiment >>>
With reference to FIG. 25 (A) and FIG. 25 (B), the structure of the floating prevention member 10 which concerns on a 4th Example is demonstrated. The float prevention member 10 according to the fourth embodiment includes a load transmission member 140 and a support member 142.

  As shown in FIG. 25A, the load transmission member 140 includes a distal end side 140a and a joint portion 140b provided on the proximal end side. The joint 140b is formed in a taper shape. The load transmission member 140 is formed with a through hole 144 that penetrates along the axial direction. A convex portion 146 is formed on the inner peripheral surface of the joint portion 140b. Further, a plurality of excavation members 148 are provided on the front surface of the distal end side 140a. The excavation member 148 includes a bit, a chip, and the like. The convex portion 146 fits into the concave portion 114 of the insertion protrusion 112 when the load transmitting member 140 excavates the excavation hole 82.

  As shown in FIG. 25B, the support member 142 includes one end 142a and the other end 142b. Further, the support member 142 is formed with a hole 150 penetrating along the axial direction. Further, the hole 150 is formed in a reverse taper shape that matches the taper gradient of the joint portion 140b so as to be fitted to the tapered joint portion 140b of the load transmitting member 140. That is, the taper-shaped minimum diameter portion is formed on the one end portion 142a side, and the taper-shaped maximum diameter portion is formed on the other end portion 142b side.

  Further, the support member 142 is fixed to the communication portion 41 of the segment 24 as shown in FIG. Furthermore, the other end 142 b of the support member 142 faces the space inside the caisson main body 16.

  Next, referring to FIG. 26, the insertion protrusion 112 used in the installation process of the anti-floating member 10 is shown. The insertion protrusion 112 has a fitting portion 112a that fits into the through holes 110, 130, and 144 of the load transmission members 102, 126, and 140 at the tip thereof, and the load transmission members 102, 126, and 140 on the inner surface of the hollow pipe 64. And a guide portion 112b for guiding along the route.

  Furthermore, a recess 114 is provided in the guide portion 112b. The concave portion 114 is configured to be fitted to convex portions 116, 134, and 146 provided on the load transmitting members 102, 126, and 140.

<Installation process of the anti-floating member according to the fourth embodiment>
Next, with reference to FIG. 27 (A) to FIG. 31 (B), a method of installing the anti-floating member 10 according to the fourth embodiment will be described. FIG. 27A shows a state in which the groundwater stored inside the caisson main body 16 is drained after the bottom plate 20 is placed in the caisson 12. The segment 24 in this embodiment is the same steel segment as in the first embodiment.

  As a first step, in FIG. 27B, the flange member 56 (FIG. 17) is interposed via the reinforcing plate 40 with respect to the support member 142 fixed to the communication portion 41 of the segment 24 constituting the side wall 18 of the caisson body 16. (Refer to (A)) with bolts 54.

  Next, as a second step, a water stop device 62 is attached to the other end portion 56b of the flange member 56 as shown in FIG. The water stop device 62 includes a hollow pipe 64, a first partition valve 68 attached in order from the distal end side 66 (left side of FIG. 28A) of the hollow pipe 64, an injection valve 70, and an exhaust mud. A valve 72, a second partition valve 74, and a gland packing 76 are provided.

  Further, as in the first embodiment, the water stop device 62 is located between the first gate valve 68, the injection valve 70, and the mud discharge valve 72, at the injection valve 70, the mud discharge valve 72, and The second gate valve 74 is configured to be removable from the first gate valve 68. The detachable structure is a known structure and is not limited to a specific structure, and thus detailed illustration thereof is omitted.

  A male screw is formed on the distal end side 66 of the hollow pipe 64. The water stop device 62 is attached to the side wall 18 via the flange member 56 by screwing the male screw of the hollow pipe 64 with the female screw 60 of the flange member 56. In FIG. 28B, the first partition valve 68, the injection valve 70, the mud discharge valve 72, and the second partition valve 74 are closed.

  As a third step, as shown in FIG. 28B, the second gate valve 74 is opened, and the load transmitting member 140 and the insertion protrusion 112 are inserted into the hollow pipe 64 from the rear end portion 78 side of the hollow pipe 64. To do. The insertion protrusion 112 is rotationally driven by a drive source (not shown). Thereby, the load transmission member 140 is rotationally driven by a drive source (not shown) via the insertion protrusion 112.

  As a fourth step, as shown in FIG. 29A, the first gate valve 68 and the mud discharge valve 72 are opened, and the load transmitting member 140 is advanced into the hole 150 of the support member 142. The skin plate 32 closing the hole 150 of the support member 142 is excavated by the plurality of excavation members 148 provided on the distal end side 140 a of the load transmission member 140, and the hole 150 is formed on the side wall 18 of the caisson 12. Open to the outside.

  At this time, water is supplied to the periphery of the excavation member 148 on the distal end side 140a through the hollow pipe 144 of the load transmitting member 140 from the water stop device 62 to the distal end side of the gland packing 76 of the hollow pipe 64. The processing waste of the skin plate 32 is removed by the member 148. Then, water is discharged from the mud discharge valve 72 together with the processing waste. The gland packing 76 is in contact with the guide portion 112 b of the insertion protrusion 112 and prevents the water from being ejected to the rear end portion 78 side of the hollow pipe 64.

  As a fifth step, as shown in FIG. 29B, the load transmission member 140 is advanced from the opening 80 formed by the excavation member 148 of the load transmission member 140 to the ground UG outside the side wall 18, The natural ground UG is excavated, and an excavation hole 82 extending from the side wall 18 to the natural ground UG is provided. The drilling water is fed into the hollow pipe 64 and flows from the excavation member 148 on the front end side 140a through the through hole 144 of the load transmission member 140 between the hollow pipe 64 and the natural ground in the direction of the rear end 78. Mud. Thereby, the earth and sand excavated from the natural ground UG by the excavation member 148 is removed. Then, the water is discharged from the mud discharge valve 72 together with the earth and sand.

  When the joint 140b of the load transmission member 140 is fitted in contact with the hole 150 of the support member 142, the rotation of the load transmission member 140 is stopped and the excavation of the natural ground UG by the excavation member 148 is stopped. Thereafter, the insertion protrusion 112 is pulled back toward the rear end 78 of the hollow pipe 64 and the second gate valve 74 is closed.

  As a sixth step, the injection valve 70 is opened, the mortar 86 is injected toward the excavation hole 82 through the through hole 144 of the load transmission member 140, and the mortar 86 is filled into the excavation hole 82. After injecting the mortar 86, the first gate valve 68 and the injection valve 70 are closed as shown in FIG.

  As a seventh step, as shown in FIG. 30B, the injection valve 70, the mud discharge valve 72 and the second partition valve 74 of the water stop device 62 are removed from the first partition valve 68.

  As an eighth step, as shown in FIG. 31A, after the mortar 86 filled in the excavation hole 82 is solidified, the first gate valve 68 is removed from the flange member 56.

  As the ninth step, as shown in FIG. 31 (B), the rear end of the load transmitting member 140 (joining portion 140b), the other end 142b of the supporting member 142, and the reinforcing plate 40 in the axial direction of the load transmitting member 140. A part of the solidified mortar 86 is removed so that the surfaces are at the same position. Then, the lid 50 is attached to the reinforcing plate 40 with bolts 54. As a result, the load transmission member 140 is firmly fixed to the side wall 18 of the caisson main body 16 via the support member 142 in a state where displacement of the load transmission member 140 in the axial direction is restricted. That is, the tip end side 140 a of the load transmitting member 140 is in a state of protruding from the side wall 18 of the caisson body 16.

  Further, the load transmitting member 140 has sufficient strength because the mortar 86 is filled between the distal end side 140a and the excavation hole 82 and between the distal end side 140a and the opening 80.

<<<< Modification Example of Fourth Embodiment >>>>
Referring to FIG. 32A, an example of a modification of the fourth embodiment is shown. The load transmission member 152 includes a distal end side 152a and a joint portion 152b. In the load transmission member 152, the diameter dimension of the distal end side 152a and the diameter dimension of the joint 152b are set to the same size. Further, the load transmission member 152 is formed with a through hole 154 penetrating along the axial direction. Further, a convex portion 156 is formed on the inner peripheral surface of the joint portion 152b. Further, a plurality of excavation members 158 are provided on the front surface of the distal end side 152a. The excavation member 158 includes a bit, a chip, and the like.

  FIG. 32B shows another example of the modification of the fourth embodiment. The load transmission member 160 includes a distal end side 160a and a joint portion 160b. In the load transmission member 160, the diameter dimension of the distal end side 160a is set smaller than the diameter dimension of the joint 160b. Further, the load transmitting member 160 is formed with a through hole 162 penetrating along the axial direction. Further, a convex portion 164 is formed on the inner peripheral surface of the joint portion 160b.

  Further, a plurality of excavation members 166 are provided on the front surface of the distal end side 160a. The excavation member 166 is provided on the distal end side 160a so as to protrude outward in the radial direction from the diameter dimension of the distal end side 160a. That is, the cutting edge diameter of the excavation member 166 is set larger than the diameter dimension of the distal end side 160a. For this reason, the frictional force between the outer peripheral surface of the distal end side 160a and the natural ground UG around the outer peripheral surface can be reduced, and the force required for excavation of the load transmitting member 160 can be reduced. The excavation member 166 includes a bit, a chip, and the like.

  Since the load transmission members 152 and 160 have the joint portions 152b and 160b formed in a cylindrical shape, the support members 142 and 160 according to the first embodiment are used instead of the support members 142 according to the fourth embodiment. The member 26 is fitted.

<<< Fifth embodiment >>>
With reference to FIG. 33 (A), the structure of the load transmission member 168 according to the fifth embodiment will be described. The load transmission member 168 includes a distal end side 168a and a joint portion 168b provided on the proximal end side. The distal end side 168 a includes an excavation unit 170 and an agitation unit 172.

  The excavation part 170 is located at the distal end of the distal end side 168a. The excavation part 170 includes a plurality of excavation members 174 at the tip thereof. Further, the excavation part 170 is provided with a draining groove 176 that is open toward the tip side. The draining groove 176 can supply the drilling water fed through the hollow pipe 64 and a through-hole 180 described later to the periphery of the excavation member 174. As a result, the earth and sand excavated by the excavating member 174 is discharged from the mud discharge valve 72 through between the front end side 168a and the surrounding natural ground UG.

  Moreover, the diameter dimension of the excavation part 170 is set smaller than the internal diameter dimension of the hole part 150 by the side of the one end part 142a of the support member 142 in which the inner surface was formed in the taper shape. The excavation member 174 includes a bit, a chip, and the like.

  In addition, the stirring unit 172 connects the excavation unit 170 and the joint 168b. The diameter dimension of the stirring unit 172 is set smaller than the diameter dimension of the excavation unit 170. The stirring unit 172 includes a plurality of protrusions 178 as “stirring means” that extend from the outer peripheral surface of the stirring unit 172 toward the outside in the radial direction.

  When the protrusion 178 rotates around the axis of the load transmitting member 168 together with the stirring portion 172, the diameter of the cutting edge circle formed by the protrusion 178 is set smaller than the inner diameter dimension of the hole 150 on the one end 142 a side of the support member 142. ing.

  Further, the load transmission member 168 is formed with a through-hole 180 penetrating the excavation part 170, the stirring part 172, and the joint part 168b in the axial direction thereof. In addition, a convex portion 182 is formed on the inner peripheral surface of the joint portion 168b. The convex portion 182 fits into the concave portion 114 of the insertion protrusion 112 when the excavation hole 82 is excavated by the load transmission member 168.

<Installation Step of Lifting Prevention Member According to Fifth Example>
The installation process of the anti-floating member 10 in the fifth embodiment is the same except that the sixth process in the fourth embodiment is different. Therefore, the description from the first step (see FIG. 27B) to the fifth step (see FIG. 29B) is omitted. Similarly, the seventh step (see FIG. 30B) to the ninth step (see FIG. 31B) are the same as the installation step in the fourth embodiment, and thus the description thereof is omitted. In the present embodiment, in the fifth step, after the excavation is stopped, the insertion rod 112 is not pulled back to the rear end portion 78 side of the hollow pipe 64, and the sixth step is performed as it is.

  As a sixth step, as shown in FIG. 33 (B), the injection valve 70 is opened, and the mortar 86 is injected toward the excavation hole 82 through the through hole 180 of the load transmission member 168, and the excavation hole 82 is injected. Fill with mortar 86. Then, while or after injecting the mortar 86, the load transmitting member 168 is rotated via the insertion protrusion 112 by a driving source (not shown). Thereby, the mortar 86 filled with the projections 178 in the excavation hole 82 is agitated.

  As shown in FIG. 33 (B), when the load transmitting member 168 is pushed into the excavation hole 82, the insertion projecting rod 112 has a plurality of mortar injection ports on its outer peripheral surface so as to correspond to the position of the injection valve 70. 112c is provided. In addition, the insertion protrusion 112 is provided with a mortar injection hole 112d that extends from the tip of the insertion protrusion 112 to the position of the mortar injection port 112c in the axial direction at the center thereof. The mortar inlet 112c and the mortar inlet 112d communicate with each other. Therefore, when the injection valve 70 is opened, the mortar 86 is supplied to the through hole 180 of the load transmitting member 168 via the mortar inlet 112c and the mortar injection hole 112d of the insertion protrusion 112.

  At this time, the soil of the natural ground UG around the load transmission member 168 and the mortar 86 can be mixed and stirred. As a result, the layer of mortar 86 solidified in a state where the soil is mixed around the load transmission member 168 can be integrated with the load transmission member 168. Thereby, the diameter of the floating prevention member 10 can be increased, and the shear resistance τ acting on the load transmission member 168 can be increased.

  After the mortar 86 is stirred, the insertion protrusion 112 is pulled back toward the rear end 78 of the hollow pipe 64, and the first partition valve 68, the injection valve 70, and the second partition valve 74 are closed. Thereafter, the seventh step (see FIG. 30B) to the ninth step (see FIG. 31B) are performed.

<<< Sixth embodiment >>>
With reference to FIG. 34 (A) thru | or FIG. 35 (B), the structure of the load transmission member 184 which concerns on a 5th Example is demonstrated. The load transmission member 184 includes a distal end side 184a and a joint portion 184b provided on the proximal end side. The joint portion 184b is formed in a tapered shape so as to be fitted to the hole portion 150 of the support member 142. In addition, the diameter dimension of the distal end side 184 a is set smaller than the inner diameter of the hole 150. That is, the diameter dimension of the distal end side 184a is set to be smaller than the diameter dimension of the minimum diameter portion in the tapered joint portion 184b.

  The distal end side 184 a includes a fixed excavation member 186 and a movable excavation member 188 as “excavation members” at the distal end. Further, the distal end side 184a includes a movable stirring member 190 as “stirring means” on the outer peripheral surface thereof.

  Further, the load transmission member 184 is formed with a through hole 192 that penetrates the distal end side 184a and the joint portion 168b in the axial direction thereof. Further, a convex portion 194 is formed on the inner peripheral surface of the joint portion 168b. The convex portion 194 is fitted into the concave portion 114 of the insertion protrusion 112 when excavating the excavation hole 82 by the load transmission member 184.

  In the load transmission member 184, the movable excavating member 188 and the movable stirring member 190 are in a closed state (see FIG. 34A) and an open state (see FIG. 34B), respectively. And can take.

  The movable excavation member 188 includes a rotating shaft 196 as shown in FIG. The movable excavation member 188 is configured to be rotatable about a rotation shaft 196. The movable excavation member 188 is in a closed state (see the one-dot chain line portion in FIG. 35A) in close contact with the outer peripheral surface of the distal end side 184a, and is open in a state of rising relative to the outer peripheral surface of the distal end side 184a. (See the solid line part in FIG. 35A).

  In the step of installing the load transmission member 184, the movable excavation member 188 is in a closed state when passing through the hole 150 of the support member 142. When the distal end side 184a comes into contact with the skin plate 32 adjacent to the one end 142a of the support member 142, the movable excavating member 188 rotates about the rotation shaft 196 as a rotation fulcrum, with respect to the outer peripheral surface of the distal end side 184a. It stands up, that is, it is in an open state.

  The cutting edge circle formed by the movable excavation member 188 in the open state is set to be larger than the inner diameter of the hole 150. Accordingly, the diameter size of the excavation hole 82 excavated by the movable excavation member 188 together with the fixed excavation member 186 can be made larger than the diameter size of the minimum diameter portion or the maximum diameter portion of the hole 150.

  Next, the movable stirring member 190 will be described. The movable stirring member 190 is provided with a rotating shaft 198 as shown in FIG. The movable stirring member 190 is configured to be rotatable about a rotation shaft 198. The state where the movable stirring member 190 is in close contact with the outer peripheral surface of the distal end side 184a (see the one-dot chain line portion in FIG. 35A) is closed, and the state where the movable stirring member 190 is raised relative to the outer peripheral surface of the distal end side 184a is opened. (See the solid line part in FIG. 35A).

  Further, the movable stirring member 190 can select a closed state or an open state by rotating the load transmission member 184. In this embodiment, by rotating the load transmission member 184 clockwise in FIG. 35B, the movable stirring member 190 rotates from the closed state with the rotation shaft 198 as a rotation fulcrum and opens. Displace to the state of being.

  On the contrary, when the movable stirring member 190 is in the open state, the movable transmission member 190 is rotated counterclockwise so that the movable stirring member 190 has the rotation shaft 198 as the rotation fulcrum from the open state. Rotates and displaces to the closed state.

  In the step of installing the load transmitting member 184, the movable stirring member 190 is in a closed state when passing through the hole 150 of the support member 142. Thereafter, when the load transmission member 184 is rotated clockwise, the movable stirring member 190 is in an open state.

  Further, the cutting edge circle formed by the movable stirring member 190 in the open state is set to the same size as the cutting edge circle formed by the movable excavation member 188, and the diameter of the minimum diameter portion or the maximum diameter portion of the hole 150 is set. It is set to be larger than the dimensions.

  Here, when the movable excavation member 188 excavates the excavation hole 82 together with the fixed excavation member 186 in the step of installing the load transmission member 184, if the rotation direction of the load transmission member 184 is counterclockwise, the movable agitation member 190 In the closed state, the load transmission member 184 digs in the outward direction of the side wall 18 of the caisson 12. For this reason, the frictional force between the load transmission member 184 and the surrounding natural ground UG can be reduced, and the force required for the excavation of the load transmission member 184 can be reduced.

  Further, after the excavation of the load transmission member 184 is completed, the mortar 86 is injected into the excavation hole 82 through the through hole 192 or after the injection, and then the load transmission member 168 is inserted through the insertion protrusion 112 by a driving source (not shown). Rotate clockwise. For this reason, the movable stirring member 190 is displaced from the closed state to the open state. Thereby, the movable stirring member 190 stirs the mortar 86 filled in the excavation hole 82.

  At this time, the soil of the natural ground UG around the load transmitting member 184 and the mortar 86 can be mixed and stirred by the movable stirring member 190. As a result, the layer of the mortar 86 solidified in a state where the soil is mixed around the load transmission member 184 can be integrated with the load transmission member 184. Accordingly, a layer of the mortar 86 larger than the inner diameter of the hole 150 of the support member 142 can be formed around the load transmission member 184, and the diameter of the anti-floating member 10 can be increased. The shear resistance τ acting on 184 can be increased.

<Installation process of the anti-floating member according to the sixth embodiment>
The installation process of the float prevention member 10 in the sixth embodiment is the same as that in the fifth embodiment. Therefore, the first process (see FIG. 27B) to the fifth process (see FIG. 29B), the sixth process (see FIG. 33B), and the seventh process (see FIG. 30B). )) To the ninth step (see FIG. 31B) will be omitted.

<<<< Modification of the sixth embodiment >>>>
In this embodiment, the rotation direction of the fixed excavation member 186 and the movable excavation member 188 excavating the excavation hole 82 is set to be counterclockwise, but may be configured to be clockwise instead.

<<< Seventh embodiment >>>
With reference to FIG. 36 (A) thru | or FIG. 37 (B), the structure of the load transmission member 200 which concerns on a 7th Example is demonstrated. The load transmission member 200 includes a distal end side 200a and a joint portion 200b provided on the proximal end side. In this embodiment, the diameter dimension of the distal end side 200a and the diameter dimension of the joint portion 200b are set to the same diameter dimension.

  The load transmitting member 200 includes a through hole 202 that penetrates the load transmitting member 200 along the axial direction. The outer diameter of the joint portion 200b is set to be the same as the inner diameter of the hole portion 28 of the support member 26 in the first embodiment. That is, the joint portion 44b can be fitted into the hole portion 28 of the support member 26 without a gap.

  Referring to FIG. 36 (B), an inner tube member 204 used in the installation process of the load transmitting member 200 in the present embodiment is shown. The inner tube member 204 includes a through hole 206 that penetrates the inner tube member 204 along the axial direction. Further, the inner pipe member 204 includes a movable excavation member 208 at the tip thereof.

  The outer dimension of the inner tube member 204 is configured to match the inner diameter dimension of the through hole 202 of the load transmitting member 200. That is, as shown in FIG. 37A, the inner surface of the through hole 202 of the load transmitting member 200 is fitted to the outer peripheral surface 204a of the inner tube member 204.

  As shown in FIG. 37 (B), the movable excavation member 208 is configured to be rotatable about a rotation shaft 210 as a rotation fulcrum. The movable excavation member 208 is parallel to the axis of the inner pipe member 204, that is, is tilted (see the one-dot chain line portion in FIG. 37B), and is perpendicular to the axis of the inner pipe member 204, that is, A standing state (see a solid line portion in FIG. 37B) can be taken.

  In addition, when the movable excavation member 208 is standing, the diameter of the cutting edge circle formed by the movable excavation member 208 is set to be larger than the outer diameter of the load transmission member 200. That is, the diameter of the cutting edge circle formed by the movable excavation member 208 is set to be larger than the diameter dimension of the hole portion 28 of the support member 26.

  On the other hand, when the movable excavation member 208 is in a tilted state, the movable excavation member 208 does not protrude outward in the radial direction from the outer peripheral surface 204 a of the inner tube member 204. In other words, when the movable excavating member 208 is in a tilted state, the load transmitting member 200 can be displaced on the outer peripheral surface 204 a of the inner tube member 204 along the axial direction of the inner tube member 204.

<Installation process of the anti-floating member according to the seventh embodiment>
Next, with reference to FIG. 38 (A) to FIG. 40 (B), a method for installing the anti-floating member 10 according to the seventh embodiment will be described. In this embodiment, the first step (see FIG. 11B) and the second step (see FIG. 12A) are the same as those in the first embodiment, and thus the description thereof is omitted. In this embodiment, the segment from which the load transmitting member 200 protrudes is the segment 24 in the first embodiment, and the support member that fixes and supports the load transmitting member 200 is the support member 26 in the first embodiment. .

  As a third step, as shown in FIG. 38 (A), the second partition valve 74 is opened, and the load transmission member 200 and the inner tube member that are driven from the rear end 78 side of the hollow pipe 64 by a drive source (not shown). 204 is inserted into the hollow pipe 64. At this time, the inner tube member 204 is inserted into the through-hole 202 of the load transmission member 200, and the movable excavation member 208 is positioned closer to the support member 26 in the axial direction than the distal end side 200 a of the load transmission member 200. That is, the movable excavation member 208 is in a rotatable state.

  As the fourth step, as shown in FIG. 38B, the first gate valve 68 and the mud discharge valve 72 are opened, and the load transmission member 200 and the inner pipe member 204 are moved into the hole 28 of the support member 26. Move forward. When the movable excavation member 208 provided at the distal end of the inner pipe member 204 comes into contact with the skin plate 32, the movable excavation member 208 is displaced from a fall state to a standing state. As a result, the movable excavating member 208 excavates the skin plate 32 closing the hole 28 of the support member 26 and opens the hole 28 toward the outside of the side wall 18 of the caisson 12.

  At this time, water is supplied to the distal end of the movable excavation member 208 through the through hole 206 of the inner pipe member 204 from the water stop device 62 to the distal end side of the gland packing 76 of the hollow pipe 64, and the movable excavation member 208 The processing waste of the skin plate 32 is removed by 208. Then, water is discharged from the mud discharge valve 72 together with the processing waste. The gland packing 76 is in contact with the outer peripheral surface 204a of the inner tube member 204 and prevents the water from being ejected to the rear end portion 78 side of the hollow pipe 64.

  As a fifth step, as shown in FIG. 39A, the load transmission member 200 and the inner pipe are passed from the opening 212 formed by the movable excavation member 208 of the inner pipe member 204 to the natural ground UG outside the side wall 18. The member 204 is advanced. At this time, the natural ground UG is excavated by the movable excavation member 208 of the inner pipe member 204, and an excavation hole 214 extending from the side wall 18 to the natural ground UG is provided. The excavation hole 214 is excavated in a cylindrical shape in the natural ground UG.

  Further, the diameter of the cutting edge circle formed by the movable excavating member 208 is larger than the outer diameter of the load transmitting member 200. For this reason, the frictional force between the excavation hole 214 and the outer peripheral surface of the load transmitting member 200 can be reduced, and consequently the frictional force when the inner pipe member 204 digs toward the outside of the side wall 18 of the caisson 12 is reduced. be able to.

  At this time, water is supplied from the distal end of the movable excavation member 208 to the distal end side of the gland packing 76 of the hollow pipe 64, and the earth and sand excavated from the natural ground UG by the movable excavation member 208 is removed. Then, the water is discharged from the mud discharge valve 72 together with the earth and sand. The drilling water is fed into the hollow pipe 64 and flows from the movable excavating member 208 between the hollow pipe 64 and the natural ground in the direction of the rear end 78 and is discharged.

  The inner pipe member 204 ends excavation when the distal end side 200a of the load transmitting member 200 protrudes to a predetermined position with respect to the natural ground UG outside the side wall 18. At this time, the joint portion 200b of the load transmitting member 200 and the hole portion 28 of the support member 26 are in a fitted state. That is, the load transmission member 200 is supported by the support member 26.

  Then, the inner pipe member 204 is pulled back to the rear end portion 78 side of the hollow pipe 64. At this time, the movable excavating member 208 is pulled back to the rear end portion 78 side to be pressed against the front end side 200a of the load transmitting member 200 and displaced from a standing state to a falling state.

  For this reason, the movable excavation member 208 is pulled back to the rear end portion 78 side of the hollow pipe 64 without interfering with the load transmission member 200. Then, the first partition valve 68, the mud discharge valve 72, and the second partition valve 74 are closed. Thereafter, the inner pipe member 204 is removed from the hollow pipe 64.

  As a sixth step, the injection valve 70 is opened, the mortar 86 is injected toward the excavation hole 214 through the through hole 202 of the load transmitting member 200, and the mortar 86 is filled into the excavation hole 214. After injecting the mortar 86, the first gate valve 68 and the injection valve 70 are closed as shown in FIG.

  As a seventh step, as shown in FIG. 40A, the injection valve 70, the mud discharge valve 72 and the second partition valve 74 of the water stop device 62 are removed from the first partition valve 68. Then, as the eighth step, after the mortar 86 filled in the excavation hole 214 is solidified, the first partition valve 68 is removed from the flange member 56.

  As the ninth step, as shown in FIG. 40B, the rear end of the load transmission member 200 (joining portion 200b), the other end 26b of the support member 26, and the reinforcing plate 40 in the axial direction of the load transmission member 200. A part of the solidified mortar 86 is removed so that the surfaces are at the same position. Then, the lid 50 is attached to the reinforcing plate 40 with bolts 54. As a result, the load transmitting member 200 is firmly fixed to the side wall 18 of the caisson main body 16 via the support member 26 in a state where displacement of the load transmitting member 200 in the axial direction is restricted. That is, the tip end side 200 a of the load transmitting member 200 is in a state of protruding from the side wall 18 of the caisson body 16.

  In this embodiment, since the excavation hole 214 is excavated in a cylindrical shape, the amount of earth and sand to be excavated can be reduced as compared with the excavation hole 82 of the first embodiment. Thereby, the excavation time of the excavation hole 214 can be shortened. That is, the work period of the caisson 12 can be shortened. Further, in this embodiment, it is possible to reduce the excessive excavation outside the outer peripheral surface of the load transmitting member 200. As a result, in this embodiment, disturbance of the natural ground UG around the load transmitting member 200 can be reduced.

  Further, the load transmitting member 200 has sufficient strength because the mortar 86 is filled between the distal end side 200a and the excavation hole 214 and between the distal end side 200a and the opening 212.

  For this reason, the floating prevention member 10 is less likely to be damaged or less likely to be damaged when the floating prevention member 10 is bent with respect to the side wall 18 of the caisson body 16 by the action of the buoyancy σ. Accordingly, the anti-floating member 10 can withstand the shear resistance of the earth and sand acting on the anti-floating member and the weight of the earth and sand, so that the caisson main body 16 has a predetermined depth against the buoyancy σ acting on the caisson main body 16. Can be maintained.

<<< Eighth embodiment >>>
With reference to FIG. 41 (A) and FIG. 41 (B), the structure of the load transmission member 216 which concerns on an 8th Example is demonstrated. The load transmission member 216 includes a distal end side 216a and a joint portion 216b provided on the proximal end side. In this embodiment, the diameter dimension of the distal end side 216a and the diameter dimension of the joint portion 216b are set to the same diameter dimension.

  Further, the load transmitting member 216 is formed with a male screw 218 that is continuous from the distal end side 216a to the joint 216b in the axial direction. The male screw 218 is configured with a pitch that engages with the female screw 106 of the hole 104 of the support member 100 according to the second embodiment.

  Furthermore, the load transmitting member 216 is provided with a sediment containing portion 220 along the axial direction. The earth and sand container 220 is configured as a cylindrical space inside the load transmission member 216. Further, the earth and sand container 220 communicates with the outer space through an opening 222 formed on the tip side 216a side.

  Further, the distal end side 216 a includes a central excavation member 224 and an outer peripheral excavation member 226. The central excavation member 224 is provided on a partition member 228 that partitions the opening 222 on the distal end side 216a. The outer peripheral excavation member 226 is disposed on the outer periphery of the opening 222 on the distal end side 216a.

  On the rear end of the load transmitting member 216, that is, on the end surface on the joint portion 216b side, an engaging convex portion 230 for engaging with a rotary tool or the like (not shown) for rotating the load transmitting member 216 around the axis. Is formed. In this embodiment, the engaging projection 230 is formed in a hexagonal shape so as to engage with a rotary tool such as a spanner.

<Installation Step of Lifting Prevention Member According to Eighth Example>
Next, with reference to FIGS. 42A to 43B, a method of installing the anti-floating member 10 according to the eighth embodiment will be described. In this embodiment, the segment from which the load transmission member 216 protrudes is the segment 118 in the second embodiment, and the support member that fixes and supports the load transmission member 216 is the support member 100 in the second embodiment. .

  Referring to FIG. 42A, the support member 100 is attached to the segment 118. A plug 122 is attached to the hole 104 of the support member 100. The external thread on the outer peripheral surface of the plug and the internal thread 106 in the hole 104 are in a screwed state.

  As a first step, as shown in FIG. 42B, the male screw 218 of the load transmitting member 216 is screwed into the female screw 106 of the hole 104 of the supporting member 100, and the load transmitting member 216 is attached to the supporting member 100. .

  As a second step, as shown in FIG. 43A, a rotary tool (not shown) is engaged with the engagement convex portion 230 at the rear end of the load transmission member 216, and the load transmission member 216 is attached to the load by the rotary tool. It is screwed with respect to the support member 100 along the axial direction of the transmission member 216. For this reason, the plug 122 is crushed by the central excavation member 224 and the outer peripheral excavation member 226 as the load transmission member 216 is screwed. The broken pieces of the plug 122 are accommodated in the earth and sand accommodating portion 220 through the opening 222.

  As a third step, as shown in FIG. 43 (B), the load transmitting member 216 is dug toward the natural ground UG outside the side wall 18 of the caisson main body 16, whereby the tip side 216a of the load transmitting member 216 is moved. The caisson body 16 is protruded toward the natural ground UG outside the side wall 18. At this time, the earth and sand excavated by the central excavation member 224 and the outer peripheral excavation member 226 are accommodated in the earth and sand accommodation part 220 through the opening 222. The load transmitting member 216 stops excavation at a position where the tip side 216a protrudes a predetermined amount from the natural ground UG outside the side wall 18 of the caisson main body 16.

  In this embodiment, the load transmission member 216 is supported and fixed to the support member 100 because the joint portion 216b is screwed into the hole 104 of the support member 100. For this reason, the load transmission member 216 is reliably fixed to the support member 100 in the axial direction. Therefore, when a force acts on the cross section in the direction perpendicular to the axis of the load transmission member 216 from the natural ground side toward the caisson main body 16 side due to a load due to earth water pressure, the displacement of the load transmission member 216 in the axial direction is reliably restricted. be able to.

  Moreover, according to the present Example, since it is the structure which screw-fits the load transmission member 216 directly to the support member 100, the water stop apparatus 62 is not required in the installation process. For this reason, it is possible to shorten the installation period of the anti-floating member 10 and reduce the construction cost.

<<< Modification Example of Eighth Embodiment >>>
Furthermore, as shown in FIGS. 44 (A) and 44 (B), the load transmitting member 216 has a grout injection part that communicates the earth / sand container 220 and the space outside the earth / sand container 220 to the rear end surface of the joint 216b. 232 may be provided. The grout injection part 232 is provided with a through hole 234. A check valve 236 is provided inside the through hole 234.

  In a state in which the tip end side 216a of the load transmitting member 216 is protruded by a predetermined amount toward the natural ground UG outside the side wall 18 of the caisson main body 16, the mortar 86 is put into the earth and sand container 220 through the through hole 234 of the grout injection part 232. Inject into the gap. And the mortar 86 is solidified in the state which filled the mortar 86 in the clearance gap between the earth and sand accommodating parts 220. FIG.

  Thereby, since the inside of the load transmission member 216 is filled with excavated earth and sand and the mortar 86, the rigidity of the load transmission member 216 can be increased. Moreover, the load transmission member 216 can adjust the magnitude of the shear resistance τ of earth and sand by adjusting the amount of protrusion of the caisson body 16 with respect to the side wall 18.

  To summarize the above description, the caisson float prevention member 10 of the present embodiment is fixed to the communication portions 41 and 119 communicating with the inside and the outside provided on the side wall 18 of the caisson 12, and the holes 28, 96, 104, 136, and 150 are fixed. Supporting members 26, 94, 100, 128, 142, and joints 44b, 88b, 90b, 92b, 102b, 126b, 140b on the base end side in the holes 28, 96, 104, 136, 150 of the supporting member. , 152b, 160b, 168b, 184b, 200b, 216b are supported, and the distal end side 44a, 88a, 90a, 92a, 102a, 126a, 140a, 152a, 160a, 168a, 184a, 200a, 216a are outside the side wall 18. Load transmitting members 44, 88, 90, 92, 102, 126, 140, 152, 1 protruding to the natural ground UG And a 0,168,184,200,216.

  The load transmitting members 44, 88, 90, 92, 126, 140, 152, 160, 168, 184, 200 are connected to the joint portions 44b, 88b, 90b, 92b, 126b, 140b, 152b, 160b, 168b, 184b, 200b. Is in surface contact with the inside of the holes 28, 96, 136, 150 and supported by the holes.

  The load transmission members 44, 126, 152, 200, and 216 are formed to have the same diameter. Further, the joint portions 92b, 140b, 168b, 184b are formed in a tapered shape, and the hole portions 96, 150 are formed in a reverse tapered shape corresponding to the tapered shape.

  The load transmitting member 102 is screwed into the hole portions 104 and 216 to restrict displacement of the load transmitting member in the axial direction. The load transmitting member 126 is fitted with the hole 136 and displacement of the load transmitting member in the axial direction is restricted. Excavation members 148, 158, 166, 174, 186, 188, 224, and 226 are provided at the distal ends of the load transmission members 140, 152, 160, 168, 184, and 216. The excavation member 166 is formed such that the diameter of the cutting edge circle formed by the excavation member is larger than the outer diameter of the distal end side 160 a of the load transmission member 160.

  Excavating members 174, 186, 188 are provided at the ends of the load transmission members 168, 184, and stirring means 178, 190 are provided on the outer periphery of the load transmission members. The stirring means 178 is a fixed protrusion, and the diameter of the cutting edge circle formed by the protrusion is smaller than the inner diameter of the hole 150. The excavation member 188 can be turned upside down, and the outer diameter made in the collapsed state is smaller than the inner diameter of the hole 150. The movable stirring member 190 can be turned upside down, and the outer diameter made in the tilted state is smaller than the inner diameter of the hole 150.

  The load transmitting member 200 is a cylindrical body, and the excavation hole 214 formed in the natural ground UG so that the load transmitting member 200 protrudes is cylindrical. The float prevention member 10 includes a lid 50 that is fixed to the inside of the side wall 18 by a bolt 54. The lid 50 regulates displacement of the load transmitting members 44, 88, 90, 92, 102, 126, 140, 152, 160, 168, 184, 200 in the axial direction. In the holes 28, 96, 104, 136, 150 of the support members 26, 94, 100, 128, 142, drainage grooves 98, 124 extending along the axial direction of the holes are formed.

  A male screw 218 is formed on the outer periphery of the load transmission member 216, and a female screw 106 is formed in the hole 104 of the support member 100. Excavation members 224 and 226 are provided at the tip of the load transmission member 216. The load transmitting member 216 is screwed with respect to the hole 104, and the soil is excavated by the excavating members 224 and 226 so that the load transmitting member 216 protrudes into the soil.

  The excavating members 224 and 226 are configured to guide the excavated soil to the earth and sand accommodating portion 220 of the load transmitting member 216. A check valve 236 capable of injecting the mortar 86 from the inside of the side wall 18 toward the earth and sand accommodating portion 220 of the load transmitting member 216 is provided at the joint portion 216b.

  The caisson float prevention member 10 is installed in the support member 26 having holes 28, 96, 104, 136, 150 fixed to the communication portions 41, 119 communicating with the inside and outside of the side wall 18 of the caisson 12. , 94, 100, 128, 142, load transmitting members 44, 88, 90, 92, 102, 126, 140, 152, 160, from the side wall 18 toward the natural ground UG outside the side wall, Digging holes 82, 214 for projecting 168, 184, 200, 216 into the soil, and load transmitting members 44, 88, 90, 92, 102, 126, 140, 152, 160, 168, 184 , 200, 216 are inserted into the excavated soil excavation holes 82, 214, and load transmission members 44, 88, 90 are inserted into the holes 28, 96, 104, 136, 150. 92, 102, 126, 140, 152, 160, 168, 184, 200, 216 joints 44b, 88b, 90b, 92b, 102b, 126b, 140b, 152b, 160b, 168b, 184b, 200b, 216b are supported. And fixing.

  The caisson float prevention member 10 is installed through the hole portion of the support member having the support member 142 having the hole portion 150 fixed to the communication portion 41 that communicates the inside and the outside provided on the side wall 18 of the caisson 12. And excavating an excavation hole 82 for projecting the load transmitting members 140, 152, 160, 168, 184 from the side walls into the ground outside the side walls, and the load transmitting members 140, 152, 160, 168, 184 projecting into the excavation hole 82 of the excavated natural ground UG, and joints 140b, 152b, 160b, 168b, 184b of the load transmitting members 140, 152, 160, 168, 184 are provided in the hole 150. Supporting and fixing.

  Further, the floating prevention member 10 is installed in the holes 82 and 214 excavated through the load transmission members 44, 88, 90, 92, 102, 126, 140, 152, 160, 168, 184, 200, and 216. Injecting mortar 86. Furthermore, the method of installing the anti-floating member 10 includes the step of rotating the load transmission members 168 and 184 and mixing and stirring the injected mortar 86 and the soil of the natural ground UG around the load transmission members 168 and 184. And solidifying the agitated mortar 86.

  In addition, the floating prevention member 10 can be installed by transmitting the load via the hole 28 of the support member 26 having the hole 28 fixed to the communication part 41 that communicates with the inside and outside of the side wall 18 of the caisson 12. A step of causing the inner tube member 204, which is disposed inside the member 200 and having the excavating member 208 at the distal end thereof, to dig into the ground UG outside the side wall 18 together with the load transmitting member 200 to project the load transmitting member 200; It includes a step of pulling out the tube member 204 from the projecting load transmitting member 200 and a step of supporting and fixing the joint portion 200b of the load transmitting member 200 in the hole 28.

  Further, the method of installing the anti-floating member 10 includes a step of injecting the mortar 86 into the excavated excavation hole 214 via the load transmission member 200 and a step of solidifying the injected mortar 86.

  Furthermore, the installation method of the anti-floating member 10 includes a step of attaching the lid 50 using the bolt 54 inside the side wall 18.

  In addition, the floating prevention member 10 is installed by transmitting the load through the hole 104 of the support member 100 having the hole 104 fixed to the communication part 119 that communicates with the inside and outside of the side wall 18 of the caisson 12. The step of screwing the member 216 with respect to the hole 104 to excavate the soil, and the step of guiding the excavated soil to the earth and sand container 220 of the load transmission member 216 and causing the load transmission member 216 to protrude into the soil. Including.

  Furthermore, the installation method of the floating prevention member 10 includes a step of injecting the mortar 86 into the earth and sand container 220 of the load transmission member 216 and a step of solidifying the injected mortar 86.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

10 floating prevention member, 12 caisson, 14 ground surface, 16 caisson main body, 18 side wall, 20 bottom plate, 22 frame, 24, 118 segment,
26, 94, 100, 128, 142 support members,
26a, 94a, 100a, 128a, 142a, one end of the support member,
26b, 94b, 100b, 128b, 142b, the other end of the support member,
28, 96, 104, 136, 150 hole, 30 inclined surface, 32 skin plate,
34 main girder, 36 joint plate, 38a rib, 38b rib, 40 reinforcing plate,
41, 119 communication part, 42, 120 bolt hole,
44, 88, 90, 92, 102, 126, 140, 152, 160, 168, 184, 200, 216 Load transmitting member,
44a, 88a, 90a, 92a, 102a, 126a, 140a, 152a, 160a, 168a, 184a, 200a, 216a Tip side,
44b, 88b, 90b, 92b, 102b, 126b, 140b, 152b, 160b, 168b, 184b, 200b, 216b
46, 52, 58, 110, 130, 144, 154, 162, 180, 192, 202, 206, 234 through hole, 48 excavation cutter, 50 lid, 50a, one side of the lid,
54 bolt, 56 flange member, 56a one end of the flange member,
56b, the other end of the flange member, 60, 106 female thread, 62 water stop device,
64 hollow pipe, 66 tip side, 68 first partition valve, 70 injection valve,
72 Valve for drainage, 74 Second partition valve, 76 Gland packing, 78 Rear end,
80 opening part, 82, 214 excavation hole, 84, 112 insertion protrusion, 84a fitting part,
84b Guide part, 86 mortar, 90c Inclined part, 98, 124 Mud ditch,
108, 218 male thread, 112a mortar inlet, 112b mortar inlet,
114 Concavity, 116, 134, 146, 156, 164, 182, 194 Convex,
122 plug, 132 fitting convex part, 138 fitting concave part, 138a guide part,
138b fitting part, 148, 158, 166, 174 excavation member, 170 excavation part,
172 Stirrer, 176 draining groove, 178 projection, 186 fixed excavation member,
188, 208 movable excavating member, 190 movable stirring member,
196, 198, 210 rotation shaft, 204 inner tube member, 212 opening,
220 earth and sand container, 222 opening, 224 central excavation member, 226 outer peripheral excavation member, 228 partition member, 230 engaging convex part, 232 grout injection part, 236 check valve

Claims (24)

A support member that is fixed to a communication portion that communicates the inside and outside of the side wall of the caisson and has a hole;
A load transmitting member in which a joint portion on the base end side is supported by the hole portion of the support member, and a distal end side protrudes into the soil outside the side wall;
With
The joint is formed in a tapered shape, and the hole is formed in a reverse tapered shape corresponding to the tapered shape.
A caisson float prevention member characterized by the above. The caisson float prevention member according to claim 1, wherein the load transmitting member is supported by the hole part in surface contact with the inside of the hole part.
A caisson float prevention member characterized by the above. A support member that is fixed to a communication portion that communicates the inside and outside of the side wall of the caisson and has a hole;
A load transmitting member in which a joint portion on the base end side is supported by the hole portion of the support member, and a distal end side protrudes into the soil outside the side wall;
With
The load transmission member is fitted into the hole and the displacement of the load transmission member in the axial direction is restricted.
A caisson float prevention member characterized by the above. The caisson float prevention member according to claim 1 or 2 , further comprising a drilling member at a tip of the load transmitting member.
A caisson float prevention member characterized by the above. The caisson float prevention member according to claim 4 , wherein the excavation member is formed such that a diameter of a cutting edge circle formed by the excavation member is larger than an outer diameter on a tip side of the load transmission member.
A caisson float prevention member characterized by the above. In the caisson float prevention member according to claim 1 or 2 , the tip of the load transmission member is provided with a drilling member, and the load transmission member is provided with a stirring means on the outer periphery.
A caisson float prevention member characterized by the above. The caisson float prevention member according to claim 6 , wherein the stirring means is a fixed protrusion, and a diameter of a cutting edge circle formed by the protrusion is smaller than an inner diameter of the hole portion.
A caisson float prevention member characterized by the above. The caisson float prevention member according to claim 6 , wherein the excavation member can be turned upside down, and an outer diameter made in a collapsed state is smaller than an inner diameter of the hole portion.
A caisson float prevention member characterized by the above. In the caisson float prevention member according to claim 6 , the stirring means can be inverted, and an outer diameter made in a collapsed state is smaller than an inner diameter of the hole.
A caisson float prevention member characterized by the above. A support member that is fixed to a communication portion that communicates the inside and outside of the side wall of the caisson and has a hole;
A cylindrical load transmitting member in which a joint portion on the base end side is supported by the hole portion of the support member, and a distal end side protrudes into the soil outside the side wall,
An inner pipe member that is disposed inside the load transmission member and includes a drilling member at a tip;
With
The inner pipe member is dug into the soil outside the side wall together with the load transmission member to form a cylindrical hole in the soil for projecting the load transmission member, and projecting into the hole Pulling out the inner tube member from the load transmitting member in a state;
A caisson float prevention member characterized by the above. The caisson float prevention member according to any one of claims 1 to 10 , further comprising a lid that is fixed to the inside of the side wall by a coupling means.
The lid body regulates displacement of the load transmitting member in an axial direction;
The floating prevention member characterized by the above-mentioned. The caisson float prevention member according to any one of claims 1 to 11 , wherein a drainage groove extending along an axial direction of the hole is formed in the hole of the support member.
The floating prevention member characterized by the above-mentioned. A support member that is fixed to a communication portion that communicates the inside and outside of the side wall of the caisson and has a hole;
A load transmitting member in which a joint portion on the base end side is supported by the hole portion of the support member, and a distal end side protrudes into the soil outside the side wall;
With
A male screw is formed on the outer periphery of the load transmission member, a female screw is formed in the hole, a drilling member is provided at the tip of the load transmission member, the load transmission member is screwed into the hole, and the Excavating the soil with a excavating member to project the load transmitting member into the soil;
The floating prevention member characterized by the above-mentioned. The caisson float prevention member according to claim 13 , wherein the excavation member is configured to guide excavated soil into the load transmission member.
The floating prevention member characterized by the above-mentioned. The caisson float prevention member according to claim 13 or 14 , wherein the joint includes a valve capable of injecting a grout material from the inside of the side wall toward the inside of the load transmission member.
The floating prevention member characterized by the above-mentioned. The inner and outer in the side wall of the caisson fixed to the communicating portion communicating, from the side wall through the pores of the support member having a hole toward the ground outside of the side wall, wherein the claim 1 A step of excavating a hole in the soil for projecting the load transmitting member according to any one of items 3 ;
Inserting the load transmitting member into the excavated soil hole;
Including supporting and fixing the joint portion of the load transmitting member in the hole portion,
Installation method of caisson anti-floating member. 4. The method according to claim 4 or claim 4, wherein the support member having a hole fixed to a communication portion provided on the side wall of the caisson is connected to the communication portion, and the hole is formed from the side wall toward the ground outside the side wall. Excavating a hole for projecting the load transmitting member according to Item 5 into the soil and projecting the load transmitting member into the excavated soil hole;
Including supporting and fixing the joint portion of the load transmitting member in the hole portion,
Installation method of caisson anti-floating member. The caisson float prevention member installation method according to claim 16 or 17 , comprising a step of injecting a grout material into the excavated hole through the load transmitting member.
Installation method of caisson anti-floating member. From the side wall toward the ground outside the side wall through the hole portion of the support member having a hole portion, which is fixed to a communication portion provided on the side wall of the caisson and which communicates between the inside and the outside. Excavating a hole for projecting the load transmitting member according to any one of items 9 into the soil and projecting the load transmitting member into the hole in the excavated soil;
Supporting and fixing the joint of the load transmitting member in the hole;
Injecting grout material into the excavated hole through the load transmitting member;
Rotating the load transmission member to mix and stir the injected grout material and the soil of the natural ground around the load transmission member; and solidifying the stirred grout material.
Installation method of caisson anti-floating member. The inner and outer in the side wall of the caisson fixed to the communicating portion communicating, via the pores of the support member having a hole, is arranged inside the load weight transmitting member, the inner tube member having a wear member to the front end Digging the load transmission member together with the load transmission member into the soil outside the side wall to project the load transmission member;
A step of pulling out the load transmission member in a state in which the inner pipe member is protruded;
Including supporting and fixing a joint provided in the load transmission member in the hole,
Installation method of caisson anti-floating member. In the caisson float prevention member installation method according to claim 20 , a step of injecting a grout material into the excavated hole through the load transmission member;
Solidifying the injected grout material,
Installation method of caisson anti-floating member. The method for installing a caisson float prevention member according to any one of claims 16 to 21 , comprising a step of attaching a lid using a coupling means inside the side wall.
Installation method of caisson anti-floating member. The load transmitting member according to claim 13 is screwed into the hole portion through the hole portion of the support member having a hole portion, which is fixed to a communication portion provided on the side wall of the caisson. And excavating the soil,
Guiding the excavated soil into the load transmission member and projecting the load transmission member into the soil;
Installation method of caisson anti-floating member. In the installation method of the caisson float prevention member according to claim 23 , a step of injecting a grout material into the load transmission member;
Solidifying the injected grout material,
Installation method of caisson anti-floating member.

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