JPH0442494B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present 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, which is usually adopted for mountain retaining walls of about one layer underground, and aims to expand the scope of construction by constructing mountain retaining walls by creating soil improvement columns. That is.

[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 aligning soil-cement solidified columns to the required depth from the bottom of the foundation of the building basement and integrating them, the passive resistance of the rooted part, that is, the resistance to active soil pressure, is increased, and the displacement of that section is increased. , prevent deformation.

〔Example〕

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

In this invention, a solidification agent is injected into the excavated soil while loosening the soil by the rotation and vertical movement of a rod with a stirring blade at the tip, and by stirring and mixing the two, a soil cement solidification column is created underground. These walls are constructed in series and in parallel, and the retaining walls A are constructed in parallel under the basement floor b of building B.

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

First, the ground at the outer periphery of basement b of building B is excavated and stirred with a rod while injecting a solidifying agent from the ground surface to the required depth below the base of the foundation of basement b, and the excavated soil and solidifying agent are mixed to solidify the outside soil cement. A columnar body (hereinafter referred to as outer columnar body 1) 1 is created (,).

Next, the inner peripheral side of this outer column 1, that is, the building B
Parallel to the side, outer column 1 from just below the foundation bottom position
Similarly, the ground up to the tip of the penetration part is excavated and stirred at the same time as the solidification agent is injected, and 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 (,) .

Next, the outer column 1 is constructed in continuation with the outer column 1 that has already been constructed (V), and further, the steps are repeated alternately to create the outer column 1 and the inner column 2 that are arranged in parallel. ().

With the above steps, outer column 1 and inner column 2 are attached to Building B.
Created by going around the outer periphery of basement b (),
Parallel retaining walls are constructed at the bottom, 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 rebar cages and steel frames are inserted to reinforce the consolidated columns.

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 It also plays the role of partitioning the ground by forming a continuous grid pattern, restraining 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 drawings]

Figure 1 shows an overview of the construction procedure of the present invention, where , is a sectional view, ,, is a plan view, and Figure 2 is a construction in which the inner column is placed below the bottom of the foundation. They are a sectional view and a plan view, respectively, showing an example. A... retaining wall, B... building, b... basement, 1
...Outer soil cement consolidated column, 2...Inner soil cement consolidated column.

Claims (1)

[Claims] 1. Excavate and stir the ground at the outer periphery of the basement of a 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 form the outside soil cement here. Consolidated columns are constructed by continuously going around the outer periphery of the basement, and are further lined up on the inner periphery of this outer soil cement consolidated column to cover the ground from just below the bottom of the foundation of the building basement to the required depth. A method of constructing a self-supporting mountain retaining wall in which the soil cement is excavated and stirred at the same time as the solidifying agent is injected, and the inner soil cement solidified column is continuously circulated to create parallel retaining walls under the basement.