JPH06240663A - Constructing method for underground continuous wall - Google Patents

Abstract

PURPOSE:To increase the horizontal bearing force of a plate-form body an underground continuous wall of which consists of vertically intercoupled blocks. CONSTITUTION:A plate-form body 40 is installed in a groove hole 26 excavated as the groove hole is filled with stabilizing liquid 24 and thereafter, the stabilizing liquid in the groove hole is cured. In a constructing method for the underground continuous wall, the plate-form body is formed such that a plurality of blocks 10, 10A, 10B, and 10C are stacked and the lower and upper blocks 10A, 10B, 10, and 10C, which are positioned adjacent to each other, are intercoupled through a stretching material 30 by which a tension is introduced. The lower and upper blocks are intercoupled during a time in which the lower block is held in the stabilizing liquid and a joining surface between the lower and upper blocks is held above the level of the stabilizing liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a continuous underground wall.

[0002]

2. Description of the Related Art Conventionally, a plurality of blocks are piled up in the stabilizing solution in a ditch hole which is excavated while filling the stabilizing solution, and these are joined by a tensioning material for introducing tension to form a plate-like body. There is a method of constructing an underground continuous wall for solidifying the above (Japanese Patent Laid-Open No. 61-134422).

[0003]

According to the conventional construction method described above, the plate-like body installed in the slot is composed of a plurality of blocks, and these are assembled at the construction site of the underground wall, PC in case of using PC board for construction of underground wall
It is possible to reduce restrictions on the size and weight of the boards in transportation, restrictions on the method of erection of the PC boards in the slots, restrictions on the lifting capacity, etc., which allows for higher depth and greater thickness. It is possible to construct a continuous underground wall of a specific size. However, in the conventional construction method, the mud component of the stabilizing liquid adheres to the joint surface between the blocks when the plate-shaped body is formed, and the mud component is consolidated over time. As a result of consolidation, the tension of the tendons that connect the blocks to each other is reduced and the bond strength between the blocks is reduced. Therefore, the horizontal yield strength of the plate-shaped body composed of a plurality of blocks is reduced. The purpose of the present invention is to
It is to increase the horizontal proof strength of a plate-like body that is composed of blocks that are vertically connected and that constitutes a continuous underground wall.

[0004]

According to the present invention, a plate-like body is installed in a groove hole excavated while filling a stabilizing solution, and thereafter,
A method for constructing an underground continuous wall for solidifying a stabilizing liquid in the slot, wherein the plate-like body is formed by stacking a plurality of blocks and connecting lower and upper blocks adjacent to each other with a tension member for introducing tension. The lower and upper blocks are connected while holding the lower block in the constant liquid and the joint surface between the lower block and the upper block above the liquid surface of the stabilizing liquid. To do.

[0005]

According to the present invention, since the blocks are connected to each other while the joint surfaces of the upper and lower blocks are held above the liquid surface of the stabilizing liquid, the joint surfaces of the joined blocks are connected to each other. There is no intervening mud in the stabilizing solution. Therefore, it is possible to avoid a decrease in the degree of coupling between the blocks due to the presence of the mud component of the stabilizing liquid, and thus it is possible to construct an underground continuous wall made of a plate-shaped body having high horizontal proof strength. Also,
When the upper and lower blocks are combined, the lower block is held in the stabilizing solution, so that the lower block can be held with a smaller force due to the buoyancy of the stabilizing solution.

[0006]

1 to 3, a block made of precast concrete for forming a plate-like body for carrying out the method for constructing an underground underground wall according to the present invention is shown by a reference numeral 10 as a whole. Has been done. The plate-shaped body is formed by stacking a plurality of blocks and connecting them to each other.

The illustrated block 10 has a rectangular front shape, a plane shape, and a side shape. The block 10 has a plurality of fixing lines 12 extending upward from the top surface thereof, and an insertion hole extending vertically for inserting a tendon 30 (see FIG. 5) described later and opening on the top and bottom surfaces of the block 10. 14 are alternately arranged in two rows in the thickness direction of the block 10 and in the width direction of the block 10. In the illustrated example, the distance between the fixing line 12 and the axis of the insertion hole 14 in each row is equal.

Each of the insertion holes 14 has a mechanical joint 28, which will be described later, for joining the lower end of the tension member and the upper end of the fixing bar 12.
Large diameter lower end 16 capable of receiving (see FIG. 5)
And a large diameter upper end portion 18 capable of receiving a fixing device 34 (see FIG. 7) described below for fixing the upper end of the tension member 30 to the block 10. The block 10 also has a plurality of ridges 20 and concave grooves corresponding to the ridges on the top surface and the bottom surface thereof, respectively, in order to position the blocks so that they do not become misaligned when they are stacked. 22 is provided.

Referring to FIG. 4, a stabilizing liquid 2 such as muddy water
The block is held by, for example, suspension in order to install the plate-like body in the slot 26 that is excavated while filling 4.
This block is arranged at the lowermost position, the insertion hole 14 is not provided, and instead, the anchor muscle 12 is implanted. In order to distinguish it from the block 10 having the insertion hole 14, the lowest block is denoted by reference numeral 10A. The upper portion of the block 10A is projected above the liquid surface of the stabilizing liquid 24, that is, above the ground.

While suspending the lowest block 10A, a mechanical joint 28 such as a coupler is used to suspend each anchoring line 12
A tension member 30 such as a PC steel wire, a PC steel rod, or a PC steel stranded wire is connected to the (FIG. 5). During the suspension, further, another block 10, which is the upper block, is suspended above the lowest block 10A and is lowered. During the lowering, each tendon 30 extending from the lowest block 10A is received in each insertion hole 14 of the block 10 (FIG. 6),
Further, the mechanical joint 28 is received in the large-diameter lower end portion 16, and the bottom surface (joint surface) of the upper block 10 abuts on the top surface (joint surface) of the lowest block 10A. The upper block 10 is aligned by the mutual fitting of the ridge 20 and the concave groove 22 described above, and is stacked on the lowest block 10A.

Thereafter, the large diameter upper end portion 18 of each insertion hole 14 is inserted.
A tension is applied to each of the tension members 30 terminating inside the fixing member 34.
The upper end portion is fixed to the block 10 in the large-diameter upper end portion 18 via (FIG. 7). As a result, both blocks 10A and 10 are connected. Both blocks 10A,
During the connection of 10, the joining surfaces of both blocks are not in the stabilizing solution 24 but are held above the level thereof, so that the stabilizing solution 24 does not exist between the contact surfaces of both blocks, and It is possible to prevent a decrease in the binding force of both blocks due to the interposition of liquid.

By the way, it is desirable to interpose a joint material between both blocks to be connected. The joint material is applied to the top surface of the lower block in advance. Referring to FIG. 6, the joint material 32 between the blocks 10A and 10 has a compressive force introduced through the tensioning member 30 during the connection between these blocks and a tensile force due to the own weight of the lower block 10A ( When the upper block 10 is hung) or the upper block is compressed by its own weight (when the lower block 10A is hung). Since the former compressive force is set to be larger than the latter tensile force, the joint material 32 is always subjected to the compressive force, and the two blocks 10A and 10 are kept in close contact with each other via the joint material 32. The joint material can transmit lateral earth pressure to the upper and lower blocks during root cutting, which will be described later.
Since it suffices that the blocks are hardened by the time the root cutting is performed, the blocks can be joined to each other and the plate-like body 40 can be held at a predetermined position without waiting for the joint material 32 to harden.

After the connection, the blocks 10 are provided, and are opened on the front and back surfaces of the blocks 10 and the insertion holes 14 are formed.
From the hole 36 communicating with the large-diameter lower end 16 of the grout 38
And each insertion hole 14 is filled with grout 38 (FIG. 8).

Next, both blocks 10 are placed until the upper part of the upper block 10 is located above the stabilizing solution 24.
Lower A and 10 and maintain this. While maintaining the suspension so that the top of the block 10 is located above the liquid surface of the stabilizing solution, another block 10 is suspended above the block and lowered to connect both blocks 10. The work performed during this period is similar to the work performed for connecting the lowest block 10A and the upper block 10 thereof.

A plurality of blocks are further stacked and the same operation is repeated to connect them to form a plate-like body 40 having a required height. By changing the tension force applied to the tension member 30 such that the coupling force of each pair of upper and lower blocks connected to each other becomes smaller according to the height position of the plate-like body 40, for example, from the lower side to the upper side. It can be set to something different. Further, the lower block can be set to have a higher strength than the upper block. Next, the plate-like body 40 is held in the slot 26 at a predetermined height position.

After that, the stabilizing solution 24 in the groove hole 26 is solidified, for example, by pouring a solidifying material (not shown) into the groove hole 26, and the plate-like body 40 is installed in the ground. Another underground plate is formed next to the plate 40, and the plates are connected to each other to construct the underground continuous wall 42. In order to solidify the stabilizing solution, for example, self-hardening mud can be used as the stabilizing solution. After the underground continuous wall 42 is constructed, root cutting is performed, for example, in order to build a structure in a space surrounded by the underground continuous wall.

FIG. 10 shows an underground continuous wall 44 constructed in accordance with the present invention that has a large wall thickness at a deep side soil pressure and a small wall thickness at a shallow side earth pressure. Due to the construction of this underground continuous wall 44, the lowest block 10B of different types, the upper block 10C, the upper block 10D, and the upper two blocks 10 similar to those described above are provided. It is used. The block 10B is similar to the block 10A described above, except that the block 10B has a large thickness dimension. The block 10C has a thickness dimension larger than that of the block 10, and one row of the anchor lines 12 provided therein does not correspond to the insertion hole 14 of one row of the block 10B below the block. Further, in the block 10D, one row is close to the other row so as to face the two rows of the fixing line 12 and the insertion hole 14 of the block 10 above it. In addition, this allows the lower block 10
One row of the anchoring bars 12 of C corresponds to the insertion holes 14 of one row of the block 10 so that they can be received.

[Brief description of drawings]

FIG. 1 is a front view of a block.

FIG. 2 is a plan view of a block.

3 is a longitudinal sectional view taken along the line 3-3 in FIG.

FIG. 4 is a vertical cross-sectional view of the lowest block suspended in the slot.

FIG. 5 is a vertical cross-sectional view of the lowermost block to which tension members are added.

FIG. 6 is a vertical cross-sectional view of an upper block suspended above the lowest block.

FIG. 7 is a vertical cross-sectional view of an upper block added to the lowest block.

FIG. 8 is a vertical cross-sectional view of the upper block after mortar filling.

FIG. 9 is a vertical cross-sectional view of a plate-shaped body composed of a plurality of blocks pressure-bonded to each other.

FIG. 10 is a vertical cross-sectional view of a plate-shaped body including blocks of different types.

[Explanation of symbols]

 10, 10A to 10D Block 24 Stabilizing liquid 26 Groove hole 30 Tension material 40 Plate-like body 42, 44 Underground continuous wall

Claims (1)

[Claims] 1. A method for constructing an underground continuous wall, wherein a plate-like body is installed in a slot hole excavated while filling a stabilizing solution, and then the stabilizing solution in the slot hole is solidified. The body is formed by stacking a plurality of blocks and connecting lower and upper blocks adjacent to each other with a tensioning tensioning member, the lower and upper blocks holding the lower blocks in the constant liquid and the lower blocks. The method for constructing an underground continuous wall, wherein the joint surface between the block and the upper block is connected while being held above the liquid surface of the stabilizing solution.