JPH0274715A - Construction method of self-standing retaining wall - Google Patents

Abstract

PURPOSE:To improve the water stopping property by providing inner soil cement consolidated pillars in a row on the inner circumferential side of outer soil cement consolidated pillars provided around the basement outer circumferential part and just below the basement base bottom position. CONSTITUTION:The ground in the basement b outer circumferential position of a building B is excavated and stirred while a solidifying agent is injected from the ground surface to the foundation bottom desired depth of the basement b to build an outer soil cement consolidated pillar 1. Then, the ground paralleled to the inner circumferential side of the pillar 1 ranging from the position just below the base bottom position to the setting part end of the pillar 1 is excavated and stirred simultaneously with the injection of the solidifying agent to build an inner soil cement consolidated pillar 2. Another pillar 1 is built continuously to the built pillar 1, and the similar work is alternately repeated to build pillars 1, 2 paralleled to each other. Further, the pillars 1, 2 are similarly built around the basement b outer circumferential part to construct a retaining wall A paralleled in the setting part under the basement b.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for constructing a self-supporting mountain retaining wall, which constructs a self-supporting mountain retaining wall by constructing a ground improvement column.

[Problem to be solved by the invention]

When the root cutting depth is about one layer of an underground structure, the main pile horizontal sheet pile wall is generally used as a self-supporting retaining wall, but with this construction method, if the depth exceeds one layer, the horizontal displacement of the retaining wall becomes large and the groundwater level increases. If it is too high, there is a problem with water-stopping properties, and the reality is that it can only be used at limited depths and ground.

This invention was made based on the weaknesses of the main pile horizontal sheet pile wall construction method that is usually adopted for underground retaining walls, and it expands the scope of construction by constructing retaining walls by creating soil improvement columns. This is what we are trying to expand.

[Means to solve the problem]

In the present invention, the ground is excavated at the same time as the solidification agent is injected.

By stirring and mixing excavated soil and solidifying agent to continuously create soil cement solidified columns, we ensure the rigidity of the mountain retaining wall, suppress horizontal displacement due to root cutting, and improve water-stopping properties. Furthermore, by arranging soil-cement solidified columns in parallel to the required depth from the bottom of the foundation of the building's basement, and by forming them as rods, the passive resistance of the rooted part, that is, the resistance to active soil pressure, is increased, and the area is displacement.

Prevent deformation.

〔Example〕

The present invention will be explained below based on the drawings showing one embodiment.

This invention involves loosening the soil by rotating and vertically moving a rondo with a stirring blade at the tip, injecting an assimilant into the excavated soil, stirring the two, and mixing them to form a continuous soil-cement solidified column underground. In other words, they are constructed in parallel, and retaining walls A are constructed in parallel under the basement of building B.

The construction procedure will be explained with reference to Fig. 1.

First, the ground at the outer periphery of the basement of Building B is excavated and stirred with a rondo while injecting a solidification agent from the ground surface to the required depth below the base of the basement foundation, and the excavated soil and solidification agent are mixed and the outside soil is cemented. Build a solidified column (hereinafter referred to as outer column 1) (1°H).

Next, parallel to the inner peripheral side of this outer column 1, that is, the building B side, the ground from just below the base of the foundation to the tip of the embedded part of the outer column 1 is similarly excavated and stirred at the same time as the solidification agent is injected. Then, an inner soil cement solidified column (hereinafter referred to as inner column 2) 2, which is the same as the outer column 1, is created (I [I, IV).

Next, build the outer column 1 in continuation with the already created outer column I (V), and then repeat steps I and II+ alternately to create the parallel outer column 1 and inner column 2. Do (Vl).

With the above procedure, the outer column 1 and the inner column 2 are constructed by going around the outer periphery of the basement of the building B (■), and a retaining wall is constructed that is parallel to the bottom of the basement, that is, at the rooting part.

By the way, if the ground is soft or the root cutting depth is large, it is expected that the earth pressure acting on the retaining wall A will increase, and if the soil cement consolidation column alone does not have enough bearing capacity, the use of a solidifying agent may be necessary. Before consolidation, core materials such as reinforcing bars and steel frames are inserted to reinforce the consolidated column.

Figure 2 shows an example of construction in which the inner columns 2 are arranged in a grid pattern under the bottom of the foundation, and the inner columns 2 support the load of building B. In this case, the inner columns 2 They also serve to partition the ground by forming a continuous grid pattern, restricting its movement, and preventing liquefaction.

〔Effect of the invention〕

The present invention is as described above, and since the retaining wall is constructed using highly rigid soil cement solidified columns, horizontal displacement due to root cutting is small, and safety during construction is improved.

The retaining walls have a large passive resistance because they are parallel at the embedded part, and the inner pillars can be used as foundation piles, and depending on how they are placed, they can be used to prevent liquefaction.

[Brief explanation of the drawing]

Figure 1 - ■ to ■ show an overview of the construction procedure of the present invention, r, II [ are cross-sectional views, n, IV, V to ■
1 is a plan view, and FIGS. 2-1 and 11 are a cross-sectional view and a plan view, respectively, showing a construction example in which the inner column body is placed under the bottom surface of the foundation. A... retaining wall, B... building, b...
...Basement, 1...Outer soil-cement solidified column, 2...Inner soil-cement solidified column. B) - Figure C ■ ■ ■

Claims (1)

[Claims] (1) Excavate the ground at the outer periphery of the basement of the building to the required depth below the base of the foundation while injecting a solidification agent by rotating a rod with stirring blades, mix the excavated soil and solidification agent, and then excavate the ground to the required depth below the base of the foundation. Consolidated soil cement columns are constructed continuously around the outer periphery of the basement, and are further lined up on the inner circumference side of this outer soil cement consolidated column, from just below the bottom of the foundation of the building basement to the required depth. A construction method for self-supporting mountain retaining walls, in which the ground is excavated and stirred at the same time as the solidification agent is injected, and the inner soil-cement solidified column is continuously circumnavigated to construct parallel retaining walls under the basement.