JPH06264437A - Construction of continuous wall in underground - Google Patents

Abstract

PURPOSE:To simplify the construction work and reduce the cost, by erecting guide walls on the ground and arranging them on constructing a continuous wall in the underground with a shallow water level and keeping the level difference between the underground water level and a stabilizing liquid with a specified value. CONSTITUTION:The underground water level is measured in advance and a guide wall 13 provided with an upper retaining wall 14a to get a necessary water level difference 5 is installed in the ground 11 and a ditch 12 is excavated. A stabilizing liquid preventing collapse of the side walls on cutting this ditch, is injected so that the water difference (t) shows a specified figure (about 2m or more). After cutting the ditch, a steel rod cage is erected inside and concrete is placed to constrtuct a continuous wall. In this way, the construction work can be simplified without subsidence of the ground.

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 an underground continuous wall suitable for application particularly when constructing a building structure on a ground having a high groundwater level.

[0002]

2. Description of the Related Art In constructing a building structure on a ground with a high groundwater level, when a continuous underground wall is used as a foundation structure, for example, as shown in FIG. After arranging No. 2, a stabilizing liquid such as a polymer or bentonite fine powder solution is filled while excavating the groove 3 in the section where the guide wall 2 is arranged. At this time,
If the water level difference t between the stabilizing liquid level in the guide wall 2 and the groundwater level is about 2 m or more, it is possible to prevent the side wall face 3a from collapsing due to the pressing force of the stabilizing liquid against the side wall face 3a of the groove 3, so that the stable ground surface is prevented. It is said that a medium continuous wall can be constructed.

Therefore, when the water level difference t cannot be satisfied, conventionally, a method as shown in FIG. 3 or 4 is used. FIG. 3 is a method generally called the deep well method, in which the groundwater level is forcibly lowered. That is, the ground 1 near the guide wall 2
An excavation hole 4 is formed by excavating to the bottom of the water table, a pump 5 is arranged in the excavation hole 4, and the groundwater is drained from a deep well 6 connected to the pump 5 to obtain the original groundwater level A. In order to obtain the required water level difference t. On the other hand, FIG. 4 shows that the ground 1 is filled with embankment 7 using good quality soil, improved soil, etc., and the construction base of the building structure is made higher than the original ground 1 to obtain the necessary water level difference t. It was done.

[0004]

However, the above-described conventional method for obtaining the water level difference t between the water level of the guide wall 2 and the groundwater level has the following disadvantages. That is, in the deep well method shown in FIG. 3, the groundwater drained has a huge amount of water, which increases working costs and may cause environmental damage by draining this groundwater. In addition, the embankment method shown in Fig. 4 requires a very large scale construction and requires the use of a certain amount of good quality earth and sand for the embankment, which contributes to the working cost and a large amount of embankment. There is also a possibility of causing the subsidence of the ground 1.

The present invention is capable of solving the above-mentioned problems, and the purpose thereof is to exert no adverse effect on the surrounding environment and to construct a continuous underground wall simply and economically. It is to provide an underground continuous wall construction method.

[0006]

According to the method of constructing an underground continuous wall of the present invention, when the underground continuous wall is constructed in the ground, the guide wall of the underground continuous wall is erected on the ground. However, the inside of the groove is filled with a stabilizing liquid higher than the upper surface of the ground to secure a water level difference from the groundwater.

[0007]

According to the method of constructing an underground continuous wall of the present invention, since the guide wall of the underground continuous wall is erected on the ground, the stabilizing liquid is provided in the groove excavated according to the section where the guide wall is arranged. When this condition is satisfied, the water level of this stabilizing liquid becomes higher than the top surface of the ground, and a sufficient water level difference with groundwater is secured, preventing the side wall surface of the groove from collapsing and simplifying construction work and reducing costs. It is possible to plan. In addition, environmental damage and ground subsidence due to construction work will not occur.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the method for constructing an underground continuous wall according to the present invention, in which reference numeral 11 is the ground. This ground 11 is an area where groundwater has a high water level, and a guide for preventing collapse of earth and sand against the pressure of the ground 11 when a groove 12 for constructing an underground continuous wall is excavated in the ground 11. A wall 13 is provided.

The guide wall 13 is the ground 11
Retaining wall portion 14 arranged perpendicularly to the retaining wall portion 1 and this retaining wall portion 1
A horizontal plate portion 1 vertically installed on the ground 4 and arranged on the surface of the ground 11
5 and the guide wall 13 is
The horizontal plate portions 15 are arranged in pairs along the side wall surfaces 12a of the grooves 12 so as to extend in directions opposite to each other with respect to the side walls 12a of the groove 12, and more specifically, The horizontal plate portion 15 and the lower portion 14b of the retaining wall portion 14 are embedded in the ground 11, and the upper portion 14a of the retaining wall portion 14 is the ground 11.
It stands up and is arranged. Then, the groove 12 is excavated in the area defined by the arrangement of the guide walls 13 and filled with the stabilizing solution.

In order to construct an underground continuous wall as described above,
First, the water level of the ground water below the ground 11 is measured, and the guide wall 13 that can sufficiently secure the water level difference described later is designed. Then, in the underground continuous wall construction section of the ground 11, the lower portion 14b of the retaining wall portion 14 is embedded in the ground 11 and the horizontal plate portion 15 is embedded on the surface of the ground 11, and the excavation width of the groove 12 is separated from each other in parallel. Then, the guide walls 13 are arranged in pairs so that the horizontal plate portions 15 extend outward from the groove 12 in the directions opposite to each other.

Then, along the excavation width by the guide wall 13, the ground 11 is excavated by an excavator such as a clam shell to form a groove 12. The excavator in this case is
Appropriate machinery and equipment should be selected according to the properties of the ground 11. The inside of the groove 12 is filled with the stabilizing liquid during the excavation. At this time, the upper portion 14a of the retaining wall portion 14 stands up on the ground 11, and the water level of the stabilizing liquid in the guide wall 13 becomes higher than the upper surface of the ground 11. The water level difference t between the water level of the stabilizing solution and the ground water level below the ground 11 is about 2 m.
If it is more than the above, a stable underground continuous wall can be constructed as described above. Therefore, it is necessary to measure the groundwater level in advance at the designing stage and secure a sufficient water level difference t against this. A suitable height of the upper portion 14a of the retaining wall portion 14 is determined. After that, a reinforcing rod cage is built inside the groove 12, and work such as placing concrete is performed to construct an underground continuous wall.

As a result, even if the sufficient water level difference t from the groundwater level cannot be satisfied, the side wall surface 12a of the groove 12 can be prevented from collapsing simply by designing and disposing an appropriate guide wall 13. Construction work can be performed efficiently. Further, since it is not necessary to perform the deep well construction method or embankment, the working cost can be reduced and the surrounding environment is not destroyed or the ground 11 is not submerged.

The guide wall 13 may be formed of any material such as a reinforced concrete structure or a steel structure as long as it has a strength required to resist the soil pressure of the ground 11 and prevent the soil of the ground 11 from collapsing. Good.

[0014]

As is apparent from the above description, according to the method of constructing an underground continuous wall of the present invention, the guide wall of the underground continuous wall is erected on the ground, and this guide wall is provided. When the ditch excavated according to the arrangement section of is filled with the stabilizing liquid, the water level of this stabilizing liquid becomes higher than the upper surface of the ground, and a sufficient water level difference with the groundwater is secured,
The collapse of the side wall surface of the groove can be prevented, and a stable underground continuous wall can be constructed. Further, at this time, since no special means for securing the water level difference is required, the construction work can be simplified and the cost can be reduced, and the adverse effects such as environmental damage to the surrounding environment and ground subsidence are not exerted.

[Brief description of drawings]

FIG. 1 is a sectional view of an underground continuous wall shown as an embodiment of the present invention.

FIG. 2 is a diagram showing a water level difference between a water level in a guide wall and a groundwater level.

FIG. 3 is a cross-sectional configuration diagram showing a deep well method shown as an example of a conventional technique.

FIG. 4 is a cross-sectional configuration diagram showing an embankment shown as an example of a conventional technique.

[Explanation of symbols]

 11 Ground 12 Groove 12a Side Wall 13 Guide Wall 14 Retaining Wall 14a Upper 14b Lower 15 Horizontal Plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Ohara 1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Corporation

Claims (1)

[Claims] 1. When constructing an underground continuous wall in the ground, a guide wall of the underground continuous wall is erected upright on the ground, and a stabilizing liquid higher than the upper surface of the ground is provided inside the groove. The underground continuous wall construction method is characterized by satisfying the following conditions and ensuring a water level difference from groundwater.