JP3850851B2 - Construction method of underground continuous wall - Google Patents

Description

  The present invention relates to a construction method for underground continuous walls.

Conventionally, as shown in FIG. 9, there is a construction method for constructing an underground continuous wall using a wall forming pillar made of precast concrete. In this method, wall-forming pillars 28 made of precast concrete are continuously installed in a slurry 27 containing a solidified liquid formed in a horizontally long excavation groove 26 excavated using a traversing excavator. The underground continuous wall 29 is constructed. As another construction method of the underground continuous wall, for example, there is an invention of JP-A-8-284154.
JP-A-8-284154

  However, in the construction method of the above-mentioned underground continuous wall, since the slurry containing the solidified liquid is solidified after about 10 to 20 hours and becomes a soil cement, when the trailing wall is constructed after this time has passed, It was necessary to excavate and remove the soil cement on the joining surface, and it was difficult to remove it without damaging the joining surface of the preceding wall. Furthermore, since the soil cement adhering to the joining surface of the preceding wall cannot be removed cleanly, the trailing wall cannot be brought into close contact with the joining surface of the preceding wall.

  This invention is made | formed in view of these problems, The objective is to provide the construction method of the underground continuous wall which can make a trailing wall contact | adhere to the joining surface of a preceding wall.

  The construction method of the underground continuous wall for solving the above-mentioned problem is that the wall forming pillar material is continuously installed in the excavation groove in which the slurry containing the solidified liquid is formed, and the leading wall is formed. Temporary pillar material is installed in close contact with the joint surface of the joint, and after the slurry is solidified to form a soil cement, the temporary pillar member is pulled out to form a connecting gap on the joint surface of the preceding wall. After forming the slurry containing the solidified liquid and excavating back to the connecting gap and excavating the excavation groove for the subsequent wall, the wall forming column material for the subsequent wall is formed on the joining surface of the preceding wall Is installed in close contact. The temporary column member is a cylinder, and the bottom surface of the cylinder is formed to be inclined downward from one side toward the side closely contacting the preceding wall, and the inside of the cylinder is a partition along the length direction. And one of the divided chambers is provided with a bottom cover and filled with a filler.

  A temporary pillar material is installed in close contact with the joint surface of the preceding wall, and after the solidified liquid slurry is solidified into a soil cement, the temporary pillar material is pulled out to the joint surface of the preceding wall. The connecting gap is formed, and the drilling groove for the trailing wall can be excavated back to the connecting gap, so that the soil cement can be excavated and removed without damaging the joining surface of the preceding wall. can do. Further, by installing the temporary pillar material in close contact with the joining surface of the preceding wall, the soil cement does not adhere to the joining surface of the preceding wall, so that it can be cleaned. The bottom surface of the temporary pillar material is formed so as to be inclined downward from one side toward the side closely contacting the preceding wall, so that the temporary pillar material can be easily inserted into the slurry containing the solidified liquid. In addition, the inside of the cylindrical body is divided into two along the length direction by partition walls, and one partition chamber is provided with a bottom cover and filled with a filler, so that the temporary column material is a slurry containing solidified liquid. When inserted into the inside, the reaction force of the bottom lid acts so that the temporary pillar material is in close contact with the joint surface. Further, the temporary columnar member tapered toward the lower side as a whole can be easily inserted into the slurry containing the solidified liquid, and can be easily pulled out from the solidified soil cement.

  Embodiments of the underground continuous wall construction method of the present invention will be described below with reference to the drawings. As shown in FIG. 1, this underground continuous wall construction method is such that a wall forming column 4 is continuously inserted into a slurry 3 containing solidified liquid in a horizontally long excavation groove 2 excavated in the ground 1. To form. The excavation groove 2 is excavated by a traverse excavator (hereinafter referred to as an excavator) 8 shown in FIG. 2, and the excavator 8 has a cutter bit 6 attached to a chain 7 attached to a chain post 5. Configured. Therefore, when the chain 7 of the chain post 5 is moved laterally while rotating at a high speed, the excavation groove 8 having the same width as the cutter bit 6 wider than the chain post 5 is excavated. Further, a discharge port 5a for discharging the solidified liquid is formed at the tip of the chain post 5, and the solidified liquid discharged from this is mixed with excavated soil to form a solidified slurry.

  Further, the wall forming column 4 is made of precast concrete, has a hollow portion 9 formed in the length direction and has a cylindrical shape, and a joint groove 10 is formed on the bonding surface.

  In the construction method of the underground continuous wall, first, the excavating machine 8 excavates the excavation groove 11 for the preceding wall. Along with this excavation, the solidified liquid discharged from the discharge port 5a at the tip of the chain post 5 is mixed and stirred in the excavated soil to form a slurry 3 containing the solidified liquid.

  Next, as shown in FIG. 3, the wall forming pillar 4 is continuously installed in the excavation groove 11 to construct the leading wall 12 having a predetermined length, and the end surface of the leading wall 12, that is, the rear surface. A temporary column 14 is installed in close contact with the joining surface 13 with the row wall. This leading wall 12 is of a size that can be constructed in one day's process, and at the end of this process, a temporary pillar in which a release agent is applied to the joint surface 13 with the subsequent wall constructed in the next day or the next process. The material 14 is installed. Note that the excavator 8 is retracted to the retreat excavation portion 15 in the excavation groove 11 for the preceding wall at the stage where the temporary pillar material 14 is installed.

  As shown in FIG. 4, the temporary column member 14 is a flat rectangular tube that is wider than the wall forming column member 4, and has a bottom surface that is lowered from one side toward the side closely contacting the preceding wall 12. It is inclined to the side. The reason why the temporary pillar member 14 is made wider than the wall forming pillar member 4 is to facilitate insertion of the wall forming pillar member 4 for the trailing wall. Further, the interior of the temporary column 14 is divided into two by a partition wall 16 provided along the length direction, and one partition chamber 17 is provided with a bottom cover 18 and filled with a filler 19 such as mortar.

  Accordingly, when the temporary pillar 14 is inserted into the solidified liquid-containing slurry 3 along the joining surface 13 of the preceding wall, the reaction force of the bottom lid 18 causes the temporary pillar 14 to closely contact the joining surface 13 side. Therefore, the temporary column member 14 is installed in close contact with the joint surface 13.

  Further, the temporary column 14 can be formed in a tapered shape as a whole in order to facilitate insertion into the solidified slurry 3. Note that the temporary column member 14 may be a cylindrical body whose bottom surface is inclined downward from one side toward the side in close contact with the preceding wall 12 without providing the bottom cover 18.

  Thus, after installing the wall forming pillar 4 of the leading wall 12, after 10 to 20 hours have passed, the solidified slurry 3 is solidified to become the soil cement 20.

  Next, as shown in FIG. 5, as the construction process of the trailing wall, when the temporary column member 14 installed on the joining surface 13 of the preceding wall is pulled out from the soil cement 20, this is caused by the release agent applied to the peripheral surface. Pull out easily. By this drawing, a connecting gap 21 is formed in the joining surface 13 of the preceding wall. This drawing can be easily performed even when the temporary column 14 is tapered as a whole.

  Then, as shown in FIG. 6, when the excavator 8 evacuated to the evacuation excavating portion 15 in the excavation groove 11 for the preceding wall is moved backward and excavated back to the connecting gap portion 21, the joining surface 13 is damaged. Therefore, the soil cement 20 can be excavated, and a clean joint surface 13 without the soil cement 20 can be formed.

  Next, the solidified liquid discharged from the discharge port 5a at the tip of the chain post 5 during the backward excavation is mixed and stirred in the excavated soil to form the solidified slurry 3 and the ground 22 ahead of the retreat excavation unit 15. Is excavated to excavate the excavation groove 23 for the trailing wall.

  Next, as shown in FIG. 7, the wall forming pillar 4 is continuously installed in the excavation groove 23 for the subsequent wall in which the slurry 3 containing the solidified liquid is formed, and the subsequent wall of a predetermined length is formed. Build 24. The wall-forming column member 4 is first installed on the joining surface 13 of the preceding wall. Since the soil cement 20 is not attached to the joining surface 13, the wall-forming pillar material 4 can be closely adhered.

  Then, as shown in FIG. 8, the temporary column member 14 is brought into close contact with the end surface of the trailing wall 24, that is, the joining surface 13 with the trailing wall constructed in the next step by the same method as described above. When the excavator 8 is installed and retracted to the retreat excavation section 15 in the excavation groove 23 for the rear wall, the construction process of the rear wall 24 or the process of one day is completed.

  Thus, the underground continuous wall 25 by the wall forming pillar 4 can be constructed by sequentially repeating the above steps. As described above, since the joining of the leading wall 12 and the trailing wall 24 at the joining surface 13 can be performed easily and accurately, the construction period can be shortened and the construction cost can be reduced.

It is a perspective view of the construction method of an underground continuous wall. It is the schematic of the principal part of an excavator. It is sectional drawing which installed the column material for temporary installation in the joint surface of a preceding wall. The temporary pillar material is shown, (1) is a sectional view in the vertical direction of the temporary pillar material installed on the joint surface, and (2) is a sectional view in the horizontal direction. (1) is a cross-sectional view of pulling out the temporary column material, and (2) is a cross-sectional view of the temporary column material. (1) is a cross-sectional view of back excavation, and (2) is a cross-sectional view of a excavation groove for a trailing wall. (1) is a cross-sectional view of installing the wall forming pillar material of the succeeding wall on the joining surface of the preceding wall, and (2) is a cross-sectional view of constructing the succeeding wall. It is sectional drawing which installed the column material for temporary installation in the joint surface of a trailing wall. It is sectional drawing of the construction method of the conventional underground continuous wall.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground 2, 11, 23, 26 Excavation groove 3, 27 Slurry containing solidified liquid 4, 28 Column material for wall formation 5 Chain post 5a Discharge port 6 Cutter bit 7 Chain 8 Transverse excavator 9 Hollow part 10 Joint groove 12 Preceding wall 13 Joint surface 14 Temporary column 15 Retreat excavation part 16 Bulkhead 17 Dividing chamber 18 Bottom cover 19 Filler 20 Soil cement 21 Connection gap 22 Ground 24 Subsequent walls 25, 29 Underground continuous wall

Claims (2)

  The wall forming column material is continuously installed in the excavation groove in which the slurry containing the solidified liquid is formed to form the preceding wall, and the temporary column material is installed in close contact with the joining surface of the preceding wall, After the slurry is solidified to become a soil cement, the above-mentioned temporary pillar material is pulled out to form a connecting gap on the joining surface of the preceding wall, and the slurry containing the solidified liquid is formed up to the connecting gap. Construction of a continuous underground wall characterized in that after drilling back and excavating the excavation groove for the trailing wall, the wall forming pillar material for the trailing wall is installed in close contact with the joint surface of the preceding wall Construction method.   The temporary column member is a cylinder, and the bottom surface of the cylinder is formed to be inclined downward from one side toward the side closely contacting the preceding wall, and the inside of the cylinder is a partition along the length direction. The construction method of the underground continuous wall according to claim 1, wherein the method is divided into two, and one of the divided chambers is provided with a bottom cover and filled with a filler.

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