JPH0214493B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for constructing underground structures such as basements.

Prior Art When performing root cutting and underground framework work on ground with a high groundwater level, conventional temporary walls, shears, drainage facilities, etc., put pressure on the construction period and cost. The reason why underground construction is considerably more expensive than above-ground construction is the expense involved in this temporary construction.

Analyzing these from a technical perspective, the fact that most of the work in current underground structure construction is based on dry work, and the fact that the root cutting side is kept dry, has emerged as an important cause. come.

Purpose of the Invention This invention was made to improve the conventional problems as described above, and it is possible to actively use water, which has traditionally been treated in the direction of being eliminated by various construction methods in the construction of underground structures. The purpose of this project is to shorten the construction period and reduce construction costs.

Composition of the Invention The method for constructing an underground structure according to the present invention stores water on the root cutting side of the underground structure body buried underground, and uses the water to support surrounding earth pressure together with the side walls of the underground structure body. The above objective is achieved by forming a slab from the upper part, lowering the water level, and then forming a lower slab.

Embodiments Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

In the figure, A is the main body of the underground structure, which is formed by pouring concrete into a formwork set above ground. Jet water is spouted from the bottom using underground water, and it exerts a reaction force on the gantry, etc. It was built underground. The underground structure main body A has four side walls 1 supported by beams 2.

Water B is stored on the root cutting side of the underground structure main body A. Water B naturally infiltrates into the underground structure body A in areas where the groundwater level is high. If the water level is low, inject it to reach a predetermined water level. This water B supports the surrounding earth pressure applied to the side wall 1 of the underground structure main body A.

Under the above conditions, underwater concrete 4 is first placed at the bottom of the underground structure main body A (Fig. 1). After the underwater concrete 4 has hardened, slabs 3 are formed on the beams 2 in order from the top of the underground structure main body A (Figures 2 and 3).

The slab 3 is formed by extending a deck plate over the beam 2 and pouring concrete on top of it.

First, form the slab 3a on the first floor above ground (second
figure). Next, we will form slab 3b on the first basement floor.
Since the water level is above the beam 2 spanning the slab 3b, the water level is lowered below the beam 2. Since the slab 3a has already been formed even if the water level is lowered, the surrounding earth pressure can be sufficiently supported by the slab 3a.

After lowering the water level, a deck plate is hung over the beam 2 to form a slab 3b. (Figure 3) As described above, the slab 3 is formed to support the surrounding earth pressure to lower the water level, and the work of forming the lower slab 3 in sequence is repeated.

After forming the slab directly above the lowest floor, water accumulated on the cut side of the underground structure main body A is drained by a pump. (Fig. 4) Effects of the Invention This invention has the above-mentioned configuration, and because it uses water such as groundwater to support the surrounding earth pressure, there is less temporary construction work such as retaining walls and shedding, and the construction period is shortened. This makes it possible to significantly reduce underground construction costs. Also, there is no need to constantly pump up groundwater,
Less impact on surrounding earth pressure.

[Brief explanation of drawings]

FIGS. 1 to 4 are longitudinal sectional views in the construction order of an embodiment of the present invention. A...Underground structure body, B...Water, 1...Side wall, 2...
Beam, 3 (a, b, c)...Slab, 4...Underwater concrete.

Claims (1)

[Claims] 1. Water is stored on the root cutting side of the underground structure body buried in the ground, and the water supports the surrounding earth pressure along with the side walls of the underground structure body, forms a slab from above, lowers the water level, and further The present invention relates to a method of constructing an underground structure characterized by forming a lower slab.