JP2001248176A - Earth retaining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve rational earth retaining work by constructing earth- retaining walls, struts, and intermediate columns within subsoil prior to excavation, in contrast to a conventional method which erects the struts while digging the ground, so that the vertical fulcrums of the earth-retaining walls become clear even in weak subsoil, resulting in a minimized displacement of the earth- retaining walls and cross-sectional forces during excavation. SOLUTION: Using an excavating machine for constructing underground continuous walls, excavation is carried out to a predetermined depth as channeled walls are held by a stabilizing solution, and a reinforcing cage 6 is inserted. Then concrete is placed to construct portions serving as the earth- retaining walls 1, the struts 4 and the intermediate columns 5. Excavation and removal of the struts or nearby unnecessary portions are repeated to complete installation of floors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mountain retaining method as a method for constructing an underground structure.

[0002]

2. Description of the Related Art In a conventional shoring method, a shoring wall is constructed, and excavation is performed by erection of supports such as cutting beams and anchors.

[0003]

Since the support of the beam, anchor, etc., is to be erected sequentially while excavating, FIG.
As shown in (1), the displacement and bending moment of the retaining wall 1 are accumulated.

[0004] In particular, when the soft ground is thickly deposited, an excessive displacement / cross-sectional force is generated in the underground portion, and in some cases, the retaining wall 1 is reinforced. In the case of such a soft ground and a nearby important structure such as a house 2 exists around the soft ground, FIG.
As shown in (1), the preceding underground beam 3 is required to improve the ground to prevent the displacement of the retaining wall 1, which leads to an increase in construction cost and construction period.

An object of the present invention is to solve the disadvantages of the prior art and to provide a digging method capable of digging while minimizing the displacement and sectional force of the gusset wall.

[0006]

According to the present invention, in order to attain the above object, an excavator for constructing an underground continuous wall is used to excavate to a predetermined depth, a reinforcing steel cage is inserted, and concrete is cast. Constructing the part that will become the retaining wall, the girder, and / or the intermediate column, repeatedly excavating, removing unnecessary parts of the preceding girder, and completing the flooring;
The main point is that the reinforcing bars of the reinforcing bar cage to be used as intermediate pillars are connected continuously by lap joints, or the retaining walls, cut beams after removal of unnecessary parts, and intermediate pillars are used as permanent structures. It is.

According to the first aspect of the present invention, unlike the conventional case where a cutting beam is erected while digging down, the excavation wall, the cutting beam, and the intermediate column are placed in the ground before excavation. Since it is constructed, the fulcrum in the vertical direction of the retaining wall becomes clear even in soft ground. As a result, the displacement and section force of the retaining wall during excavation are minimized, and a reasonable retaining operation is achieved.

Further, since the fulcrum in the vertical direction is clearly defined as described above, it is possible to grasp in advance the sectional force generated in the retaining structure.

According to the second aspect of the present invention, in addition to the above-mentioned effects, the retaining wall, the cut beam, and the intermediate column can also resist the bending moment by using the lap joint in the reinforcing bar in the horizontal direction. Member.

[0010] According to the third aspect of the present invention, the mountain retaining wall, the cut beam after removing the unnecessary portion, and the intermediate pillar can be used as a permanent construction to streamline the construction. Since the intermediate pillar is made of reinforced concrete with high rigidity, it can be used for supporting piles and main girder of temporary piers.

[0011]

Embodiments of the present invention will be described below in detail. FIG. 1 is a plan view showing an embodiment of a mountain retaining method according to the present invention, and FIG. 2 is a vertical sectional side view of the same, in which 1 is a retaining wall, 4 is a cut beam, and 5 is an intermediate column.

According to the present invention, the intermediate column 5 may or may not be provided. However, the retaining wall 1, the cutting beam 4, and the intermediate column 5 are formed by using an excavator for constructing an underground continuous wall. Excavation is performed to a predetermined depth while maintaining the stable liquid, and a reinforcing cage 6 is inserted as shown in FIG. 5, and concrete is cast using a tremy tube or the like, or is pumped.

The reinforcing cage 6 serving as the retaining wall 1, the cutting beam 4, and the intermediate column 5 is provided with necessary portions at the lap joint 10 of the reinforcing bars.
To continue. In this case, the intermediate pillars 5 are assembled with reinforcing bars so as to form a plane cruciform at appropriate intervals in the upper and lower tiers in relation to the cutting beam 4, and each end of the cruciform becomes a joint.

Although the illustration of the construction method and protective measures of the joint between the reinforcing bars 6 is omitted, a side steel plate and a joint protective plate or a campus sheet and a joint protective box are used.

In this case, the construction order may be such that any one of the retaining wall 1, the cutting beam 4, and the intermediate column 5 precedes. In addition, the reinforcing bar is not inserted into the unnecessary portion α of the intermediate portion in the vertical direction, and is surrounded by an iron plate 7 or the like so that concrete does not go around in this portion so that it can be easily removed later. You can keep it.

In this way, the portions to be the retaining wall 1, the cutting beam 4, and the intermediate column 5 are constructed in advance, and the internal excavation is performed as shown in FIG. Along with this internal excavation, the cutting beam 4 previously constructed or the unnecessary portion α in the vicinity thereof is removed. In addition,
Even in the case where the concrete or the reinforced concrete is not surrounded by the iron plate 7 or the like, the concrete or the reinforced concrete can be destroyed and removed by the breaker or the like.

Further, a temporary pier 8 used for excavator installation or the like during excavation can be erected by passing a main girder on the cutting beam 4. This is because the cutting beams 4 and the intermediate pillars 5 can be used together with the support piles, the main girder and the like of the temporary pier 8.

As described above, the excavation and the removal of the unnecessary portion α in the vicinity of the cutting beam 4 or the vicinity thereof are repeated, and the flooring is completed as shown in FIG. In FIG. 4, reference numeral 9 denotes a flooring surface.

Further, the retaining wall 1, the beam 4 after removing unnecessary parts, and the intermediate pillar 5 constructed in this manner are reinforced concrete (RC) structures having high rigidity, and these are used as the frame of the main structure. You can also.

[0020]

As described above, the mountain retaining method according to the present invention is different from the conventional method in which a cutting beam is erected while digging down, and before the excavation, the retaining wall, the cutting beam, and the intermediate pillar are connected. Because it is built in the ground, the vertical fulcrum of the retaining wall becomes clear even in soft ground, and as a result, displacement and cross-sectional force of the retaining wall during excavation are minimized, making it a reasonable retaining work Things.

Further, since the fulcrum in the vertical direction is clear as described above, it is possible to grasp in advance the sectional force generated in the mountain retaining frame.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a mountain retaining method according to the present invention.

FIG. 2 is a longitudinal sectional side view showing one embodiment of the mountain retaining method of the present invention.

FIG. 3 is a vertical sectional side view of a second step showing one embodiment of the mountain retaining method of the present invention.

FIG. 4 is a vertical sectional side view of a third step showing one embodiment of the mountain retaining method of the present invention.

FIG. 5 is a side view of a bar arrangement state showing one embodiment of the mountain retaining method of the present invention.

FIG. 6 is an explanatory view of a mountain retaining work.

FIG. 7 is an explanatory diagram of a mountain retaining work when a preceding underground beam is provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mountain retaining wall 2 ... House etc. 3 ... Preceding underground beam 4 ... Cut-off beam 5 ... Intermediate pillar 6 ... Reinforced basket 7 ... Iron plate 8 ... Temporary pier 9 ... Flooring surface 10 ... Lap joint alpha ... Unnecessary part

Claims (3)

[Claims] 1. Excavating to a predetermined depth using an excavator for underground continuous wall construction, inserting a reinforced cage, casting concrete, and forming a retaining wall, a cut beam, and / or an intermediate column. A mountain retaining method characterized by repeating the construction of a part, excavation, and removal of unnecessary parts of the preceding girder to complete flooring. 2. The method according to claim 1, wherein the reinforcing bars of the reinforcing cages serving as the retaining wall, the cut beam, and / or the intermediate column are connected by a lap joint. 3. The mountain retaining wall, the cut beam after removing unnecessary parts, and the intermediate pillar are used as a permanent structure.
The retaining method described.