JP2007009610A - Rectangular press-in caisson and edge earth removal method by the rectangular press-in caisson - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rectangular press-in caisson and an edge earth removal method by the rectangular press-in caisson capable of surely sinking the rectangular press-in caisson without being required for any water spraying equipment so that earth and sand are not adhered to the inside of an edge when the rectangular press-in caisson is sank. <P>SOLUTION: An earth and sand guiding means 12 forming a projection toward the inside of a caisson is provided to the inside of the edge 3, and the earth and sand guiding means 12 is equipped with an inclined plane 13 guiding earth and sand on the edge side relatively moving along the inside 6 of the edge 3 by the settlement of the caisson toward the direction separated from the above of the inside 6 of the edge 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rectangular press-in caisson and a blade-edge soil removal method using the rectangular press-in caisson.

Conventionally, in ground excavation by the open caisson method, vertical excavation by a clam shell is mainly performed in an area surrounded by an inner peripheral surface of a caisson main body of a rectangular press-in caisson. And since the earth and sand along the blade edge on the lower side of the caisson main body cannot be directly excavated by vertical excavation, the excavation method is to excavate the part along the inner peripheral surface of the caisson main body, and then the caisson Is pressed to sink and the earth and sand hidden at the position of the blade edge is pushed out to the preceding excavation part by the pressure input of the blade edge, and the pushed earth and sand is discharged.
In excavation using this rectangular press-in caisson, the rectangular press-in caisson may not sink due to the geology of the formation that the blade reaches. For example, a blade edge may reach the clay layer, and earth and sand of the clay layer may adhere to the inner surface of the blade edge, and even when pressed, the earth and sand cannot be pushed out from the blade edge side, and the rectangular press-in caisson cannot be lowered. In addition, at the corner of the edge of the rectangular press-in caisson, the sediment on the two sides of the blade edge is pushed out when it sinks, but the extruded earth and sand are pressed against each other to be consolidated. Therefore, the extruding of earth and sand from the corner of the blade edge becomes very bad, and the earth and sand sticks to the inner surface of the edge of the edge of the blade and pressure input is more than necessary. There is.
For this reason, as a contrivance for avoiding the impossible of press-fitting by sticking due to adhesion of earth and sand to the inner surface of the blade edge, a method of removing the earth and sand adhering to the inner surface of the blade edge by spraying high pressure water to the blade edge Has been proposed (see Patent Document 1).
JP 09-279598 A

However, the above-described method of ejecting high-pressure water to remove earth and sand adhering to the inner surface of the blade edge requires a facility for supplying water to the blade edge side, which raises the problem of raising the facility cost. In addition, the supplied water makes the mud corresponding to the area of the inner peripheral surface of the caisson main body become muddy water, and there arises a problem that it becomes difficult to remove the soil using a drilling device such as a clamshell.
Therefore, in view of the above circumstances, the present invention has an object to prevent earth and sand from adhering to and sticking to the inner surface of the blade edge when the rectangular press-fitted caisson is submerged, and is surely rectangular without requiring the water spraying equipment described above. The purpose is to sink the press-in caisson.

  The present invention has been made in consideration of the above-mentioned problems, and is provided with earth and sand guiding means that protrudes inward toward the caisson on the inner surface of the blade edge, and the earth and sand guiding means extends along the inner surface of the blade edge due to caisson settlement. The present invention provides a rectangular press-fitting caisson characterized in that it has an inclined surface that guides the earth and sand on the blade edge side that moves relatively toward the direction away from the inner surface of the blade edge, and solves the above problems. is there.

Moreover, in the said invention, the inclined surface of the said earth-and-sand guide means can be made into the plate surface shape long in one direction.
Further, in the above invention, the earth and sand guiding means is located on each of the inner surfaces of the two surfaces in the corner of the blade edge, and the inclination of the edge on the blade edge side of the inclined surface of each of the earth and sand guiding means is along the blade edge. It is possible to assume an upward slope in a direction away from the edge of the blade edge.
Further, in the above invention, the earth and sand guiding means is located in each region from the edge of the blade edge to the center on the four inner surfaces of the blade, and the inclination of the edge on the blade edge side of the inclined surface of each earth and sand guiding means. However, it is possible to make it go up along the inner surface of the blade edge in a direction away from the corner of the blade edge.
Further, in the above invention, the earth and sand guiding means is located on each of the four inner surfaces of the blade edge, and the edge on the blade edge side of the inclined surface of each earth and sand guiding means is along the lateral width direction of the inner surface of the blade edge. Can be.
Further, in the above invention, the earth and sand guiding means is located on each of the four inner surfaces of the blade edge, and the edge on the inner surface side of the blade edge on the inclined surface of each of the earth and sand guiding means is the longitudinal width direction of the inner surface of the blade edge. It is possible that

  Furthermore, another invention is to excavate the ground along the inner peripheral surface of the rectangular press-in caisson, and then sink the rectangular press-in caisson into the ground, and the earth and sand moving relative to the earth and sand guiding means by the sinking is This rectangular press-in caisson is a method for discharging the sand at the edge of a rectangular press-in caisson, which is guided by an inclined surface of the guide means in a direction away from the inner surface of the blade and pushed out inward of the caisson. The above-mentioned problems are solved by providing a method for discharging the blade edge soil.

  According to the invention of claim 1, when the rectangular press-in caisson sinks, the pressure on the inner surface of the blade edge is gradually increased with the upward movement along the inner surface from the lower end of the blade edge relative to the blade edge. The earth and sand that tends to rise collide with the earth and sand guide means during the movement, and are guided away from the inner surface of the blade edge by the inclined surface of the earth and sand guide means, and the earth and sand adhere to and adhere to the inner surface of the blade edge. Since it is pushed out toward the inner side of the caisson, the earth and sand on the inner surface side of the blade edge is appropriately discharged, and the rectangular press-in caisson is satisfactorily sunk.

  According to the second aspect of the present invention, since the inclined surface of the earth and sand guiding means has a plate-like shape that is long in one direction, the earth and sand guiding means against the earth and sand that moves along the inner surface of the blade edge when the caisson sinks. Cutting into the shape of a blade makes it easy for the earth and sand to break or collapse, and the earth and sand on the inner surface side of the blade edge is smoothly pushed out to the inner side of the caisson.

  According to the invention of claim 3, during subsidence, a force that pushes the earth and sand moving upward along the inner surfaces of the two surfaces at the edge of the blade edge to the opposite side of the edge of the blade edge works. The earth and sand at the corner of the blade edge is pushed out to the inside of the caisson without becoming a compacted state without causing collision of the earth and sand at the corner of the mouth.

  According to invention of Claim 4, the pressure to the horizontal direction of the earth and sand which moves upwards along the center side of the inner surface of a blade edge | tip can be reduced in the case of subsidence. That is, the earth and sand that moves upward along the center side of the inner surface of the blade edge presses the earth and sand that moves upward along the edge part of the blade edge from the lateral direction. Causes the earth and sand in the range from the center side of the inner surface of the blade edge to the edge of the blade edge to collapse and crack, making it difficult for pressure to be transmitted laterally from the earth and sand moving upward along the center side of the inner surface of the blade edge. be able to.

  According to the fifth aspect of the present invention, when sinking, the earth and sand are separated from the inner surface in the lateral width direction of the inner surface of the blade, and the rectangular press-in caisson appropriately sinks.

  According to the sixth aspect of the present invention, when sinking, the earth and sand corresponding to the inclined surface of the earth and sand guiding means in the longitudinal direction moves along the inclined surface and moves to the caisson inward side. With the earth and sand rising in the vicinity of the means, it can be separated from the inner surface of the blade edge so that it does not cause adhesion to the inner surface of the blade edge so that the rectangular press-in caisson sinks properly. Become.

  According to the invention of claim 7, in order to extrude the earth and sand by the earth and sand guiding means to the previously excavated area, it is very easy to break or collapse on the earth and sand side that moves along the inner surface of the blade edge during subsidence. Therefore, the earth and sand are pushed out more reliably by the earth and sand guiding means.

Next, the present invention will be described in detail based on the embodiment shown in FIGS.
In the figure, reference numeral 1 denotes a rectangular press-in caisson. In the rectangular press-in caisson 1, a blade section 3 having a rectangular cross section and positioned at the lower part of a reinforced concrete caisson body 2 has an outer peripheral surface 4 as shown in FIG. As shown in FIG. 3, each of the inner surfaces 6 of the four surfaces constituting the inner peripheral surface 5 is vertical and has a gently rising slope 8 in the vicinity of the lower edge 7 of the blade edge. The surface shape is such that the inclination angle is changed so as to be continuous with the inclined slope 9.
FIG. 3 shows the structure of the blade edge 3. As shown in FIG. 3, steel plates 10 are attached to the outer peripheral surface 4 and the inner peripheral surface 5 of the blade 3 as blade metal fittings, and each of these steel plates 10 is a reinforcing bar member on the caisson body 2 side (not shown). It is connected with.

In the four cutting edge corners 11 of the cutting edge 3, earth and sand guiding means 12 are provided on the steel plate 10 serving as the inclined surface 9 of each of the two inner surfaces 6 constituting the cutting edge corner 11, and the caisson. It is provided in a state of projecting toward the inside. The earth and sand guiding means 12 is made of L-shaped steel having a length dimension sufficiently larger than the cross-sectional height dimension, and is fixed to the steel plate 10 by welding. Then, as shown in FIG. 3, each of the earth and sand guiding means 12 makes the lower end edge 14 of the inclined surface 13 on the side of the lower edge 7 of the blade edge continuous without any gap between the inner surface 6 and the blade of the inclined surface 13. The inclination in the mouth cross-sectional direction has an elevation angle α with respect to the horizontal, and is provided so as to have a sufficient inclination angle with respect to the inner surface 6.
Thus, each of the earth and sand guide means 12 includes the inclined surface 13, and the inclination of the inclined surface 13 in the blade cross-sectional direction has an elevation angle α with respect to the horizontal. Therefore, the earth and sand on the blade edge side, which moves relatively along the inner surface 6 of the blade edge 3 due to caisson settlement, is directed away from the inner surface 6 of the blade edge 3. I will guide you.

Furthermore, the earth and sand guiding means 12 located on the two inner surfaces 6 of the blade corner 11 has an upward slope along the blade 3 toward the direction away from the blade corner 11 as shown in FIGS. It is attached at an angle. As a result, the inclination of the lower end edge 14 of each inclined surface 13 on the blade edge 3 side becomes an upward gradient in the direction away from the blade edge corner 11 along the blade edge 3, and the inclined surface 13 itself is inclined in the longitudinal direction. Yes.
In the blade corner 11, the inclined surfaces 13 are inclined so as to rise upward in the direction away from the blade corner 11 along the blade 3. The earth and sand moving upward along the inner surface 6 is pushed out by the earth and sand guiding means 12 located on the inner surface 6 where the earth and sand are opposed to the side opposite to the blade edge corner 11, and the earth and sand are at a high pressure at the edge angle 11. Then it will not collide and will be guided to the inside of the caisson properly.

  In excavation using the rectangular press-in caisson 1 having the above-described configuration, first, excavation equipment such as a clam shell is applied from the ground at a position along the inner peripheral surface of the rectangular press-in caisson 1 to the ground corresponding to the inner region of the caisson Vertical excavation using Thereafter, the blade edge 3 of the rectangular press-in caisson 1 is press-fitted into the ground and submerged. By the subsidence, the earth and sand are pushed toward the inside of the caisson by the inner surface 6 at a portion other than the edge portion 11 of the blade edge, and pushed out to the previously excavated region side. In addition, the earth and sand that move relative to the earth and sand guiding means 12 are guided toward the inside of the caisson while being separated from the inner surface 6 by the inclined surface 13 even in the edge portion 11 of the blade edge, and the area excavated earlier. Extrude. Extrusion of earth and sand on the blade edge 3 side is automatically performed by the sinking of the rectangular press-fitting caisson 1, and no special personnel are required in the portion of the blade edge 3. Since the earth and sand are pushed out by the earth and sand guiding means 12, the earth and sand are properly discharged without increasing the pressure input. Thus, the process may be repeated so that the earth and sand discharged in the previous excavation area is discharged, and the excavation work at the position along the inner peripheral surface of the caisson is returned again.

In the rectangular press-in caisson 1 described above, the earth and sand guiding means 12 is provided for the four corners 11 of the blade edge. However, the present invention is not limited to this form. Number, position and tilt state can be selected.
FIG. 5 shows one example, and a plurality of earth and sand guide means 12 are positioned in each of the areas 15 from the edge corner 11 side to the center of each inner surface 6, and each of the earth and sand guide means 12 in each area 15 is inclined. The slope of the lower end edge 14 of the surface 13 may be inclined upward in the direction away from the blade corner 11 along the inner surface 6, and the slope of the inclined surface 13 in the longitudinal direction may be set.
FIG. 6 shows another example. In this example, a plurality of earth and sand guide means 12 are positioned up and down on each inner surface 6, and the lower end edge 14 of each inclined surface 13 is along the lateral width direction of the inner surface 6, and the inclined surface 13 is inclined in the longitudinal direction. Is set.
FIG. 7 shows still another example. In this example, a plurality of earth and sand guiding means 12 are positioned at intervals on each inner surface 6, and the edge 16 on the inner surface 6 side of each inclined surface 13 is inclined along the longitudinal width direction of the inner surface 6. 13 is vertical. Each of the illustrated earth and sand guiding means 12 has two inclined surfaces 13, and when sinking, the earth and sand rises along the inclined surface 13 at the respective portions of the two inclined surfaces 13, thereby causing the inside of the caisson. It moves to the side, and the earth and sand facing the portion in the vicinity of the earth and sand guiding means 12 is also moved away from the inner surface 6 so that the adhesion to the inner surface 6 can be prevented.

It is explanatory drawing which shows the caisson bottom face state which looked at an example of the rectangular press-in caisson based on this invention from the blade-mouth side. It is explanatory drawing which shows schematically the longitudinal cross-sectional shape of the blade edge in an example. It is explanatory drawing which shows the attachment state of the earth-and-sand guide means in the blade edge in an example in a cross section. It is explanatory drawing which shows the attachment state of the earth-and-sand guide means of a blade-mouth corner | angular part by developing partially the blade inner peripheral surface in an example. It is explanatory drawing which shows the attachment state of the earth and sand guide means by developing a part of blade inner peripheral surface in another example. It is explanatory drawing which shows the attachment state of the earth and sand guide means by developing a part of blade inner peripheral surface in another example. It is explanatory drawing which shows the attachment state of the earth and sand guide means by developing a part of blade inner peripheral surface in another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rectangular press-in caisson 2 ... Caisson main body 3 ... Blade edge 6 ... Inner surface 7 ... Blade edge lower edge 11 ... Blade edge corner 12 ... Sediment guide means 13 ... Inclined surface 14 ... Lower edge

Claims (7)

  The inner surface of the blade edge is provided with earth and sand guide means that protrudes inward toward the caisson, and the earth and sand guide means moves the earth and sand on the blade edge side that moves relatively along the inner surface of the blade edge by caisson settlement to the edge of the blade edge. A rectangular press-in caisson comprising an inclined surface that is guided in a direction away from the inner surface of.   2. The rectangular press-in caisson according to claim 1, wherein the inclined surface of the earth and sand guiding means has a plate shape that is long in one direction.   The earth and sand guiding means is located on each of the two inner surfaces of the corner of the blade edge, and the inclination of the edge on the blade edge side of the inclined surface of each of the earth and sand guiding means is away from the edge of the blade edge along the blade edge. The rectangular press-in caisson according to claim 1, wherein the rectangular press-in caisson is inclined upward.   The earth and sand guide means is located in each region from the edge side to the center of the four inner surfaces of the blade edge, and the inclination of the edge on the blade edge side of the inclined surface of each earth and sand guide means is the inner surface of the blade edge. The rectangular press-in caisson according to claim 1, wherein the slope is an upward slope toward the direction away from the corner of the blade edge.   3. The earth and sand guiding means is located on each of the four inner surfaces of the blade edge, and the edge on the blade edge side of the inclined surface of each earth and sand guiding means is along the lateral width direction of the inner surface of the blade edge. The rectangular press-in caisson described in 1.   The earth and sand guide means is located on each of the four inner surfaces of the blade edge, and the edge on the inner surface side of the blade edge on the inclined surface of each earth and sand guide means is along the longitudinal width direction of the inner surface of the blade edge. The rectangular press-fitting caisson according to 1 or 2. After excavating the ground along the inner peripheral surface of the rectangular press-in caisson according to any one of claims 1 to 6, the rectangular press-in caisson is sunk into the ground, and the earth and sand moving relative to the earth and sand guiding means by sinking A method for discharging soil at the edge of a rectangular press-in caisson, characterized in that the inclined surface of the earth and sand guide means guides the direction away from the inner surface of the blade and pushes it inward of the caisson.

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