JPS5869924A - Construction of sheathing wall having upper part consisting of underground continuous wall and lower part of pillar-row pile - Google Patents

Abstract

PURPOSE:To rationalize and economize the construction of a sheathing wall by making up the sheathing wall whose upper part consists of an underground continuous wall and whose lower part cosists of a pillar-row pile under the ground condition that the upper part is soft ground and the lower part is rock bed. CONSTITUTION:An iron bar cage 9, etc., are erected in an excavated trench formed in a soft ground, box-thrust steel pipes are erected at a given interval, and concrete 10, etc., is placed. After a hardening agent, e.g., concrete, etc., is hardened, the box-thrust pipes 8 are pulled out by jacks, etc., the holes 11 thus formed are inserted with drills, and holes 12 for pillar rows are drilled in the rock bed below the underground continuous wall 3. Then, iron bars, etc., are ercted into the holes 12 and then concrete is placed to form a pillar-row pile 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing an earth retaining wall in the case of open excavation down to bedrock under ground conditions where the upper part is a soft layer and the lower part is bedrock.

Under this type of ground condition, the earth retaining structure will interfere with the upper soft layer, causing sediment and groundwater to flow out.
Constructing a continuous wall on bedrock presents difficulties in terms of workability. In addition, the strength of the bedrock is high, so there is no need to suppress the ground with a "surface" such as an underground continuous wall, and it is easy to construct a bowl for rock excavation.In this invention, the upper part is an underground continuous wall,
Considering an earth retaining wall whose lower part is made up of column piles, the construction method for an earth retaining wall whose lower part is an underground continuous wall and whose lower part is made of column piles is to insert boxed pipes into an excavated trench at predetermined intervals. Construct an underground continuous wall, then pull out the box pipe to make a box hole in the underground continuous wall, insert a drilling machine into the box hole to make an excavated hole in the ground below the underground continuous wall, and install piles in this excavated hole. It is considered as 41 mold to form a row of pillars by inserting them. It has been confirmed that steel materials such as the box-opened pipes can be easily pulled out by jacking or the like after construction of an underground continuous wall by applying an anti-friction agent beforehand.

The present invention will be described below based on illustrated embodiments.

The first all shows an example in which rock anchors are used for earth retaining, and the underground continuous wall 5 constructed in the soft layer 1
Internal excavation and internal construction will be carried out using this underground continuity and column piles 4 constructed on the bedrock 2 below as an integral earth retaining wall.

In the figure, 5 indicates a rock anchor, and the tortoise indicates an internal excavation surface.

In addition, Figure 2 shows an example in which it is used for circular reverse winding earth retention, with the upper part being an underground continuous wall 3 and the lower part being columnar piles 4.
An earth retaining wall is constructed, and reverse-wound concrete is placed while internal excavation is performed to form a reverse-wound ring 6.

Figures 3 to 8 are conceptual diagrams showing the construction procedure for this earth retaining wall, and the work is carried out in the following steps.

(1) First, excavation #17 is excavated to construct an underground continuous wall in soft ground 1 (see Figure 3). To stabilize trench walls, muddy water such as bentonite muddy water is often used.

(2) Necessary steel materials such as reinforcing steel are erected in the excavated trench 7, and at the same time, boxed pipes 8 such as steel pipes are erected at predetermined intervals. After that, concrete IJ-10 etc. are poured (see Figure 4).

Even if fill cement or other hardening material is used instead of concrete 10, it will not deteriorate. Note that, as described above, by applying an anti-friction agent to the box-opening pipe 8 in advance, construction becomes easier.

(5) Conc IJ -) After curing the hardening material such as 10, pull out the boxed pipe 8 with a jack or the like (see Figure 5).
.

(41) A drilling machine such as a boring machine is inserted into the box hole 11 formed by pulling out the box pipe 8, and the columnar part of the bedrock 2 below the underground continuous wall 1 is bored (see Fig. 6).

(5) Reinforcing bars 15 or steel materials are placed in the excavated hole 12 obtained in (4) above (see Figure 7), and concrete is poured to form column piles 4 (see Figure 8).

In this embodiment, the column piles 4 are cast-in-place reinforced concrete piles, but are not limited to this.

This invention has the above-mentioned configuration, and in the ground condition where the upper part is soft ground and the lower part is rocky ground, an earth retaining wall is constructed in which the upper part is an underground continuous wall and the lower part is on column piles, so it is possible to construct it rationally and economically. It is possible. Further, after constructing the underground continuous wall, the box holes obtained by pulling out the box pipe can be used for constructing column piles, and the box pipe can be used repeatedly.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view when it is used for rock anchor earth retaining, and FIG. 2 is a perspective view of the vertical cross-section when it is used for circular reverse winding earth retaining. FIGS. 3 to 8 are perspective views in longitudinal section showing the outline of the construction procedure. 1. Soft layer, 2. Bedrock, 3. Underground continuous wall, 4.
Column pile, 5ss anchor, 6... Reverse winding ring, 7... Excavation groove, 8... Box punched pipe, 9... Rebar, 10... Concrete, 11... Box punched hole, 12... Drilled hole, 13 ...Reinforced steel. Agent Tomoichi Hisakado 1
Figure 3111 Figure 2 Figure 4 Figure 5 Figure 7 f゛-1 61'4 11 11 81\J

Claims (1)

[Scope of Claims] (1) An underground continuous wall is constructed with boxed pipes inserted at predetermined intervals in an excavated trench, and then the boxed pipes are pulled out to create boxed holes in the underground continuity; A drilling machine is inserted into the box hole to make an excavation hole in the ground below the underground continuous wall, and piles are erected in the excavated hole to form column piles.The upper part is the underground continuous wall and the lower part is the underground continuous wall. A construction method for earth retaining walls consisting of rows of column piles. (2) When bundling the boxed pipes, apply an anti-friction agent in advance.''<*1lv-Construction of an earth retaining wall consisting of an underground continuous wall in the upper part and columnar piles in the lower part as described in claim 1i1Q1. (5) The construction method of an earth retaining wall whose upper part is an underground continuous wall and whose lower part is a column pile according to claim 1 or 2, wherein the column pile is a cast-in-place reinforced concrete pile.