JP4754513B2 - Liner plate displacement prevention device and displacement prevention system - Google Patents

Description

  The present invention is a displacement prevention for preventing the sinking, falling off, and displacement of the liner plate used for preventing the collapse of the excavation wall when forming an excavation hole in the ground surface in the foundation work of a structure such as a steel tower. The present invention relates to an apparatus and a displacement prevention system.

  In the foundation construction of power transmission towers, for example, inverted T-shaped concrete blocks are buried in the ground, but in that case, concrete is placed in the formwork by assembling the formwork in the excavation hole formed in the ground And cured to complete. When forming excavation holes, in order to prevent the collapse of the excavation wall and to stop the spring water from the ground, a liner plate ring with a curved steel plate called a liner plate assembled in an annular shape according to the progress of excavation As a result, the work of assembling in multiple steps on the excavation wall from the ground side to the ground is carried out. The ends of the upper and lower liner plate rings are fastened and fixed by bolts or the like. After completion of excavation and assembly of the liner plate ring by reinforcing the excavation wall with the liner plate ring and repeating further excavation and installation of the liner plate ring, the mold is assembled in the excavation hole, Concrete is placed and hardened with the necessary steel and rebar placed. After the concrete is hardened, the liner plate ring is removed from the lower side, and then backfilling is performed. In foundation works for power transmission towers, it is necessary to maintain extremely high positional accuracy of the foundation. Therefore, the dimensional accuracy of the drilling hole and the position accuracy of the liner plate ring that reinforces the inner wall of the drilling hole (liner plate ring diameter) The actual situation is that an error of about 10 cm is allowed. For this reason, when the excavation hole is formed, excavation using a heavy machine is allowed at the center of the hole, but accuracy is secured at the peripheral part of the hole by excavation by human power.

  A problem in the excavation method using the liner plate is the occurrence of slack such as falling off of the liner plate and inclination due to the formation of a gap between the outer peripheral surface of the liner plate ring as a heavy object and the excavation wall. . When the slack occurs, not only reworking and danger is caused, but also various problems in foundation work such as a decrease in installation accuracy of the mold to be assembled in the excavation hole are caused. In order to prevent such slack, the back surface of the liner plate ring has been filled with a back-filling material made of cementitious material and solidified. However, in this method, the back-filling material is fixed to the liner plate. Not only does the removal of the plate become difficult, but there is a high possibility that reuse of the liner plate is hindered due to breakage or contamination of the liner plate. In particular, recent civil engineering contractors often borrow a liner plate from a rental contractor in order to reduce the cost. Therefore, if damage or defacement occurs, there is a problem that a compensation problem occurs at the time of return, and costs are increased. Moreover, in excavation work on soft ground with a large amount of spring water, there is a problem that the liner plate cannot be prevented from being displaced, fallen off, tilted, etc. by its own backfill material alone.

In Patent Document 1, a container made of a synthetic resin is disposed between the outer peripheral surface of a liner plate ring in which a plurality of liner plates are assembled in an annular shape and a drilling wall of a drilling hole, and a filler is injected into the container. Then, a technique has been disclosed in which local collapse and spring water are coped with by expanding and hardening to fill a gap between the liner plate ring and the excavation wall.
However, even if such a container is used as a backfill material, it is not possible to prevent the liner plate ring from falling off and being displaced due to collapse of the excavation wall in soft ground with a large amount of spring water.
Further, in Patent Document 2, an infusion bag is disposed between the liner plate ring and the inner wall of the excavation hole, and then the infusion bag is filled with a backfill material and cured to prevent the liner plate ring from falling off. However, in this case as well, in soft ground with a large amount of spring water, it is not possible to prevent the liner plate ring from falling off and being displaced due to collapse of the excavation wall.

Next, in order to cope with the above problems, conventionally, an H-shaped steel material is assembled in a cross-beam shape on an iron plate installed on the ground surface at the periphery of the opening of the excavation hole so that the excavation hole opening is located at the center. In some cases, the steel plate and the uppermost liner plate ring are fixed with bolts, wires or the like to prevent the liner plate ring from sinking.
However, since this method requires the use of heavy steel plates and H-type steel materials, transportation equipment and heavy equipment for installation work are required, leading to problems of increased cost and reduced workability. .
JP-A-8-338196 JP-A-11-81854

When forming excavation holes to construct structures in the ground in various foundation works, work to dig while reinforcing the excavation wall in stages using liner plates to prevent collapse of the excavation holes However, because the liner plate itself is heavy, it is not easy to prevent displacement such as sinking, dropping off, tilting, etc. . In particular, the back-filling material is likely to drop and shift its position, so that there is a limit to the liner plate displacement prevention effect.
Also, the entire liner plate ring installed in multiple stages by installing an H-shaped steel material assembled in a cross-beam shape around the opening of the excavation hole on the ground and holding the uppermost liner plate ring by this H-shaped steel material Although a method of preventing the dropout of the steel has been implemented, there is a problem that it takes a lot of work and cost to transport and assemble heavy steel.
The present invention has been made in view of the above, and is a displacement prevention device for suspending and holding liner plate rings installed in multiple stages on the inner wall of an excavation hole on the ground surface side, and can be transported and installed manually. The purpose is to provide something.

In order to solve the above-described problem, the liner plate displacement prevention device according to the invention of claim 1 is configured to prevent the liner plate ring attached in an annular shape over the entire circumference of the wall surface of the excavation hole in the process of forming the excavation hole in the ground. A liner plate displacement prevention device that prevents the pin plate surface from holding the outer peripheral surface of the liner plate ring positioned at the uppermost position by expanding, and the ground contact that exerts an effect of preventing sinking by contacting the ground surface. An annular bag having a surface is provided , and a rigid plate is disposed at a suitable position on the outer surface excluding the inner surface of the annular bag.
In order to prevent the liner plate ring that reinforces the inner wall of the excavation hole from being sunk, dropped off, or displaced due to being arranged in multiple stages in the vertical direction, fluid can be used as a means to hold the uppermost liner plate ring. An annular bag body that expands and hardens by being filled with is used. Since the uppermost liner plate ring is clamped and held by the expanded annular bag body, the liner plate displacement prevention device can support the load of the liner plate ring group with the ground surface.
Further, for example, by disposing a rigid plate on the upper surface or outer peripheral surface of the annular bag body or the bag body, damage to the bag body due to heavy machinery or equipment can be prevented. Moreover, the installation stability with respect to a ground surface is securable by arrange | positioning a rigid board in a bottom face.

According to a second aspect of the present invention, in the first aspect, the annular bag is composed of a plurality of bags connected in an annular shape.
As the annular bag body, it is possible to reduce the weight by using a structure in which a plurality of small bag bodies are connected rather than a single large bag body, so that the handleability can be improved.
A third aspect of the invention is characterized in that, in the first or second aspect, the annular bag body and the bag body are inflated by filling a fluid therein and contracted by discharging the fluid.
As the fluid, a gas such as air or a liquid such as water is used.
According to a fourth aspect of the present invention, in the first, second, or third aspect, the annular bag body and the bag body are configured to expand at least in the inner diameter direction when filled with fluid.
It is possible to effectively press-contact by configuring the annular bag body, which is a portion that contacts and presses the liner plate ring, to expand only the inner peripheral surface of the bag body.

The invention of claim 5 is characterized in that, in claim 2 or 3, the fluid is filled in a lump by communicating between the plurality of bags.
This is because the configuration is simplified and the workability is improved as compared with the case of performing filling work on individual bags .

According to a sixth aspect of the present invention, in any one of the second to fifth aspects, the bag body and the liner plate ring are mechanically fixed.
The connecting force of the bag body arranged in an annular shape can be increased.
A seventh aspect of the invention is characterized in that, in any one of the second to sixth aspects, the rigid plates included in the bag bodies are connected by a connecting member.
It is effective to use a rigid plate as a support means for the connecting member.
A liner plate displacement prevention system according to an eighth aspect of the invention includes the liner plate displacement prevention device according to any one of the first to seventh aspects and a pressure tank that performs pressure management in the annular bag body. It is characterized by that.
Even when the pressure in the annular bag and the bag is lowered, the pressure drop can be compensated.

The liner plate displacement prevention device according to the present invention has a pressure contact surface that holds the outer peripheral surface of the liner plate ring positioned at the highest position by expansion, and a ground contact that exerts an effect of preventing sinking by contacting the ground surface. Since it uses an annular bag body with a surface and a bag body, it can be transported and installed by hand, and it provides a device that suspends and holds the liner plate ring installed in multiple stages on the inner wall of the excavation hole on the ground surface side. can do.
According to this, even if a backfill material is not used, it is possible to prevent the liner plate ring from dropping and the excavation wall from collapsing when a gap is generated between the liner plate ring and the excavation wall.

The total weight of the plurality of liner plate rings can be held by the displacement prevention device, and as long as the clamping force due to the expansion of the bag body and the installation stability to the ground surface are sufficiently secured, Since complete catching on the ground surface can be ensured, more effective support strength can be ensured than filling the backfill material and holding the liner plate ring only by frictional force. In particular, the backfill material is likely to come off or fall, but the displacement prevention device of the present invention does not have such a fatal defect.
In addition, it is possible to reinforce the tightening force by the bag body by mechanically engaging between the displacement prevention device and the liner plate ring with a bolt or the like, and even if the fluid leaks, the bolt This makes it possible to maintain the supporting force and prevent the liner plate ring from falling off.

Since this displacement prevention device does not require the use of a concrete-based backfill material, it can be reused repeatedly without being damaged or soiled during removal. Therefore, the construction cost can be reduced.
Moreover, since it is comprised from the bag body which consists of resin etc., it is significantly lightweight compared with H-type steel materials etc., and conveyance and installation by human power are attained.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
1 (a) and 1 (b) are an external perspective view and a longitudinal sectional view showing a state in which the liner plate displacement prevention device of the present invention is assembled to the uppermost part of the liner plate ring group installed in the excavation hole in multiple stages. FIGS. 2A and 2B are an external perspective view of a bag body and a perspective view of a main part showing a connection state between the bag bodies. FIG. 3 is a cross-sectional view showing a configuration of a modified example. 4A and 4B are a front view and a plan view showing a state before injecting a fluid (injection material) into the bag body, and FIGS. 5A and 5B show the fluid in the bag body. It is the front view and top view which show the state after inject | pouring.
This liner plate displacement prevention device (hereinafter referred to as “displacement prevention device”) 1 is a liner plate that is assembled in an annular shape over the entire peripheral surface of the wall surface 51a of the excavation hole in the process of excavating and forming the excavation hole 51 in the ground 50. This is a means for preventing the ring 30 from falling off.

The liner plate ring 30 is formed by connecting a plurality of liner plates 31 each formed of an iron plate in a required curved shape in an annular shape, and excavating the ground 50 to a required depth (the vertical width of one liner plate). At that time, it is assembled to cover the excavation wall. The liner plates connected in the circumferential direction are connected by a connecting tool such as a bolt. In the present embodiment, a part of the uppermost liner plate ring protrudes above the ground surface and is used as an attachment portion for assembling the displacement prevention device 1.
After the uppermost liner plate ring 30 has been assembled to the inner wall of the excavation hole, the bottom of the excavation hole is further excavated by the vertical width of the next stage liner plate ring, and the next stage liner plate ring is assembled to the excavated inner wall. By repeating the above, the liner plate ring 30 is sequentially installed in multiple stages. The connecting edges of the liner plate rings in the vertical position are appropriately fixed by a fixing tool such as a bolt or a wire.
For example, when the installation of the uppermost liner plate ring 30 is completed, the displacement prevention device 1 is assembled and fixed to the outer peripheral surface protruding from the ground, so that the second and subsequent liner plate rings are sequentially installed. The total weight of 30 can be supported by the contact surface with the ground surface, and the displacement (sinking, dropping, misalignment, etc.) of each liner plate ring can be prevented.
The displacement prevention device 1 has a pinching surface 3 that pinches and holds the outer peripheral surface of the liner plate ring 30 positioned at the uppermost position by expanding, and a ground contact surface 4 that contacts the ground surface and exhibits a sinking prevention effect. The annular bag body 2 is provided.

The annular bag body 2 is composed of, for example, a plurality of bag bodies 10 connected in an annular shape. Each bag 10 is configured to expand when it is filled with a fluid (injection material) such as air or water, and to contract when the fluid is discharged. Specifically, for example, a resin sheet having a sufficient strength and a sufficient thickness, such as polyvinyl chloride and polyethylene, is formed in a bag shape, and the fluid inlet (which may also serve as an outlet) 11 is provided. It has a configuration with a stopper attached. When the inlet 11 is closed with a stopper, the bag body 10 constitutes a sealed space. Moreover, it connects so that the fluid can flow between the adjacent bag bodies 10 by connecting between the inlets 11 of each bag body, or between the communicating ports 12 provided separately from the inlet port by the connecting pipe body 13. . In order to reinforce the outer surface of the bag body, it may be covered with a wire net (not shown).
Furthermore, by fixing the top plate (protective plate = rigid plate) 15 made of a metal plate or a resin plate to the upper surface of the bag body 10 in advance or retrofitting, the bag body is damaged by touching heavy machinery or equipment. It is configured so that it is possible to prevent the operator from getting on, or an operator can get on the upper surface of each bag. Alternatively, a similar protective effect can be expected by arranging a rigid plate on the outer peripheral surface of the bag body 10. Moreover, the installation stability with respect to a ground surface is securable by arrange | positioning a rigid board to the bottom face of a bag body.

Further, by connecting the top plates 15 with a metal connecting member 16, the bags 10 are fixed. That is, by using the connecting member 16 to mechanically connect the bags, the degree of adhesion between each bag and the uppermost liner plate ring and the connecting force can be increased. By connecting each bag in an annular shape and holding the outer peripheral surface of the liner plate ring with pressure, various stresses applied to the liner plate ring can be uniformly distributed to each bag, and the support strength , Support stability can be enhanced.
Alternatively, when rigid plates are arranged on the outer peripheral surface of the bag body or other portions, these rigid plates may be connected by a connecting member.
In addition, in order to ensure the installation stability of the liner plate ring with respect to the ground surface, a plate material made of a rigid material may be fixed to the lower surface of the bag body 10 in advance.

Further, the shape and structure of the resin sheet constituting the bag body 10 is such that when the inside is filled with fluid, the inner surface (surface 3 facing the outer surface of the liner plate) side mainly expands and is pressure-bonded to the outer surface of the liner plate. Is set in advance, it is possible to effectively obtain a pressure-bonding force with a smaller amount of fluid and fluid pressure. For example, the resin sheet material constituting the peripheral surface excluding the inner side surface 3 of the bag body is made thicker than the inner side surface to make it difficult to expand, so that only the inner resin sheet is easily expanded.
Due to the strong pinching force generated inward by the expansion of the individual bag bodies 10 constituting the annular bag body 2, the force that the annular bag body 2 adheres to the outer peripheral surface of the uppermost liner plate ring 30 is applied. In order to increase the bonding force between the annular bag body 2 and the liner plate ring 30, from the top to the outside of the individual liner plates 31 constituting the uppermost liner plate ring 30 as shown in FIG. 3. It is preferable to project the overhang member 32. The effect of preventing the liner plate ring from sinking can be enhanced by engaging and seating the projecting member 32 on the top surface of each top plate.
The operation of supplying and inflating the fluid inside each bag body 10 may be performed individually for each bag body, but a plurality or all of the bag bodies 10 are connected and connected by the connecting pipe body 13. By supplying fluid to one bag body, it is possible to inflate a plurality of or all of the bag bodies at once and to press-fit them to the outer surface of the liner plate ring. When a gas such as air is used as the fluid, an air compressor is used, and when a liquid such as water is used as the fluid, a filling operation is performed using a pump. Liquids are superior in terms of ease of fluid pressure control.

When the displacement preventing device 1 as described above is assembled to the uppermost liner plate ring 30, the side surface of the liner plate ring partially protruding above the ground surface 50 is as shown in FIGS. After each bag body 10 having the top plate 15 on the upper surface is arranged in an annular shape, the top plates of the bag bodies are connected by a connecting member 16 as shown in FIG. Alternatively, as shown in FIG. 3, an overhang member 32 protrudes from the uppermost liner plate ring 30 and is engaged with the top plate 15.
In this state, the annular bag 2 is inflated by injecting a fluid from the fluid supply means into each bag. Then, as shown in FIG. 5, each bag body 10 expands in the inner diameter direction and is in a state of being pressure-bonded to the outer peripheral surface of the liner plate ring. As a result, it becomes possible to suspend the uppermost liner plate ring and the subsequent and subsequent liner plate rings sequentially connected thereto, and there is a gap between each liner plate ring and the excavation wall. Even if it is formed, each liner plate ring will not sink, drop off, or be displaced.
It goes without saying that the displacement prevention effect can be further enhanced by using the displacement prevention device 1 of the present invention together with the conventional backfilling material.
The peripheral edge of the opening of the excavation hole 51 is dug over a predetermined width to form an annular groove, and the displacement prevention device 1 projects from the ground surface by housing the displacement prevention device 1 in the annular groove. The height can be reduced, and the displacement prevention device can be prevented from becoming an obstacle to each work around the excavation hole.

Next, FIGS. 4 and 5 show a liner plate displacement prevention system in which a pressure tank 40 that performs pressure management in the annular bag body 2 (each bag body 10) is connected to the displacement prevention device 1. FIG.
This displacement prevention system is configured to perform pressure management by always applying pressure by connecting the pressure tank 40 to the inlet 11 of the bag body 10.
FIG. 4 shows a state before filling each bag body with fluid. In this state, each bag body is not expanded, but after filling with the fluid, each bag body is at its maximum as shown in FIG. It will be in the state crimped | bonded to the outer peripheral surface of the upper liner plate ring. If the fluid pressure in any one of the bags is reduced by connecting the pressure tank, the shortage of pressure can be compensated. Also, an abnormality due to the internal pressure drop of each bag can be detected.

  In the above embodiment, an example in which the outer peripheral surface of the liner plate ring is held while being pressurized by using a bag body that expands and hardens by filling the fluid inside, but on the contrary, sufficient strength and airtightness is provided. The required amount of resin particles, etc., is filled in advance in a bag made of a material having the properties, and the resin particles are tightly adhered to each other by evacuating and contracting the bag using a vacuum pump. It is also possible to use a bag that hardens in the state of being allowed to come. By arbitrarily setting the shape of the bag body in advance, the bag body hardened by evacuation can be made into an arbitrary shape. For this reason, it becomes possible to utilize the bag body which filled with the resin particle instead of the H type steel material in the construction method which prevented the settlement of the liner plate ring using the conventional H type steel material. Since the weight of the bag body combined with the resin particles is significantly lighter than that of the H-type steel material, it is easy to transport and install, and can be cured by simply venting from the bag body on site, It is possible to prevent the liner plate ring from sinking by assembling the evacuated bag body in the form of a cross-beam to the liner plate ring or any other state.

(A) And (b) is the external appearance perspective view which shows the state which assembled | attached the liner plate displacement prevention apparatus of this invention with respect to the uppermost part of the liner plate ring group installed in the excavation hole in multiple steps, and a longitudinal cross-sectional view. is there. (A) And (b) is the external appearance perspective view of a bag body, and the principal part perspective view which shows the connection state between bag bodies. It is sectional drawing which shows the structure of the modification of this invention. (A) And (b) is the front view and top view which show the state before inject | pouring a fluid (injection material) in a bag body. (A) And (b) is the front view and top view which show the state after inject | pouring the fluid into the bag body.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Displacement prevention apparatus, 2 ... Ring bag body, 3 ... Clamping surface (inside surface), 4 ... Ground contact surface, 10 ... Bag body, 11 ... Injection port, 12 ... Communication port, 13 ... Connection pipe body, 15 ... Top plate, 16 ... connecting member, 30 ... liner plate ring, 31 ... liner plate, 32 ... overhang member, 40 ... pressure tank, 50 ... ground, 51 ... excavation hole, 51a ... wall surface.

Claims (8)

In the process of forming a drilling hole in the ground, a liner plate displacement prevention device that prevents the liner plate ring assembled in an annular shape around the entire circumference of the wall of the drilling hole,
Pressing surfaces for clamping holding an outer peripheral surface of the liner plate ring at the top by expansion, and comprises an annular bag body having a ground contacting surface to exert a preventing effect sinking in contact with the ground surface, the A liner plate displacement prevention device characterized in that a rigid plate is disposed at a suitable position on the outer surface excluding the inner surface of the annular bag .   The liner plate displacement prevention device according to claim 1, wherein the annular bag body includes a plurality of annularly connected bag bodies.   The liner plate displacement prevention device according to claim 1 or 2, wherein the annular bag body and the bag body are inflated by filling a fluid therein and contracted by discharging the fluid.   4. The liner plate displacement prevention device according to claim 1, wherein the annular bag body and the bag body are configured to expand at least in an inner diameter direction when the fluid is filled. 5.   The liner plate displacement prevention device according to claim 2 or 3, wherein the fluid is filled at once by communicating between the plurality of bags. Includes a projecting member which projects outwardly from the upper portion of the liner plate ring, according to any one of claims 2 to 5, characterized in that the mechanically fixed and the該張producing member said rigid plate Liner plate displacement prevention device. The liner plate displacement prevention device according to any one of claims 2 to 6, wherein the rigid plates included in the bags are connected by a connecting member. A liner plate displacement prevention system comprising: the liner plate displacement prevention device according to any one of claims 1 to 7 ; and a pressure tank that performs pressure management in the annular bag body.

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