JP2536701B2 - Earth retaining method for deep excavation - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil retaining method for deep excavation.

[0002]

2. Description of the Related Art Generally, earth retaining works are used for the purpose of preventing collapse of the excavated earth and sand when constructing an underground structure. Conventionally, earth retaining works have been used as earth retaining works of this type. A sheet pile construction method using steel sheet piles or horizontal sheet piles for partitioning to block the is known and is most commonly practiced.

[0003]

However, this sheet pile method requires a large number of supporting materials because the sheet piles need to be supported by a large number of uprights and supports made of cut beams. There is a problem that a lot of manpower is required for assembling the work, and the work tends to be complicated.

In addition, the length of the parent pile into which the steel sheet pile or the horizontal sheet pile is put is limited, and accordingly, the depth of the retaining wall which can be constructed is naturally limited, and the deep underground structure has a large depth. There was a problem that it was not possible to deal with the construction of objects.

The present invention has been proposed in order to solve the above-mentioned conventional problems, and an object thereof is to provide a soil retaining method for deep excavation which enables construction of a deep retaining wall. To do.

[0006]

According to the deep soil retaining method of the present invention, an earth retaining wall to be constructed is vertically divided into a plurality of stages of elements, and (A) excavation of a narrow vertical hole in the ground. First, in order of formation of a reinforced concrete earth retaining wall inside the vertical hole with a release material on the inside ground side, excavation of the soil inside the retaining wall, and fixing of the retaining wall to the ground with a rock bolt. A step of constructing a first-stage (uppermost) element, (B) further excavating the inner ground of the first-stage element beyond the lower end of the element, and then, immediately below the first-stage element, a second-stage narrow vertical hole Excavate the above (A)
Constructing a second stage element in the same manner as the process,
(C) A step of filling the gap between the lower end of the first-stage element and the upper end of the second-stage element with a reinforcing bar concrete to connect both elements, and (D), (B) and (C) steps are repeated to further lower element The above-mentioned object is achieved by constructing / connecting the whole of the earth retaining wall by sequentially constructing lower elements in the depth direction while connecting the upper and lower ends of the elements of each step. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A deep soil retaining method according to the present invention will be described below in order with reference to FIGS.

(1) First, the vertical hole 1 is excavated in the ground in the shape of a groove having a constant width (see FIG. 1). Although the vertical hole 1 varies depending on the shape of the underground structure, the vertical hole 1 is excavated in a groove shape that is continuous in the lateral direction while maintaining a predetermined depth, and is continuous in a circular or rectangular annular shape (see FIGS. 9 and 10).

For excavation of the vertical hole 1, a chain saw excavator as shown in FIGS. 20 and 21 may be used, as well as a disc cutter, a hydraulic excavator, or a clam shell.
Use an excavator that can continuously excavate in a groove shape.

(2) The reinforcing bar 2 is inserted into the vertical hole 1 and fixed to the central portion of the vertical hole 1 (see FIG. 2). As the reinforcing bar 2, for example, a material having high rigidity such as a lattice reinforcing bar or a lath wire mesh, or a material having relatively low rigidity such as a wire mesh is used.

The reinforcing bar 2 has a high rigidity, for example,
When using lattice reinforcements, either overlap the edges of adjacent lattice reinforcements (see Figures 11 and 12), or make a male joint 3 and a steel pipe made of T-shaped steel that engage each other at the edges. The lattice joints are made continuous by the ordinary joint method of the reinforcement in the underground continuous wall construction such as by providing the female joint 4 (Figs. 13 and 14). Install a spacer (not shown) so that the cover thickness can be secured.

When a reinforcing bar 2 having a relatively small rigidity, for example, a wire net is used, H is placed in the vertical hole 1.
Pillars 6 made of shaped steel or the like are built at predetermined intervals, and tightly bound to the pillars 6 to support them (see FIG. 15).

A mold release material 7 such as asphalt roofing is inserted inside the reinforcing bar 2 together with the reinforcing bar 2 (see FIG. 23). This mold release material 7 is a concrete 8 to be placed later.
This is to cut off the adhesion between the soil and the soil inside thereof and to prevent the element 14 from being applied with an inward force during excavation of the inner ground.

After inserting the reinforcing bar 2 and the release material 7, the vertical hole 1 is slightly backfilled.

(3) Concrete 8 is poured into the vertical hole 1 and cured until sufficient strength is developed (see FIG. 2).

When the concrete 8 is poured all over the vertical hole 1 at a time, it is poured continuously while being careful not to separate it by the concrete pump 9 (see FIG. 24).

When a plurality of parts are divided and driven, the reinforcing bar 2 is fixed to the center of the vertical hole 1 from both sides by a tubular packer 10 and a reaction force receiver 11, and the vertical hole 1 is divided into plural parts. Partition and concrete 8 for each section
(See Figures 17, 18, and 19).

It should be noted that the packer 10 and the reaction force receiver 11 are set in advance in the reinforcing bar 2 and built in the vertical hole 1 together with the reinforcing bar 2, and the packer 10 is filled with concrete 8 therein. To expand (Fig. 18,1
9).

As a method of partitioning the vertical hole 1, a rocking pipe having a diameter substantially equal to the lateral width of the vertical hole 1 is formed at the connecting portion of the left and right reinforcing bars 2.
There is also a way to build 12 (see Figure 16).

In this case, in order to fix the reinforcing bar 2 in the vertical hole 1, a connecting bar 13 is projected on the side of the locking pipe 12, and the end of the reinforcing bar 2 is tightly connected to or over the connecting bar 13. Wrap.

When fiber concrete is used as the concrete 8, the reinforcing bar 2 can be omitted.

(4) When the concrete 8 develops sufficient strength, the inside of the concrete 8, that is, the concrete wall body
Excavate the inside of 14 (hereinafter simply referred to as "element 14") (see Fig. 3). For excavation, a conventionally used excavator is used.

(5) After excavating to some extent, the excavation is temporarily stopped, and a plurality of lock bolts 15 are installed in the surrounding ground on the back side of the element 14 from the front side to firmly secure the upper end of the element 14 in the surrounding ground. To prepare for the subsequent excavation of the ground (see Fig. 4). When the upper end of the element 14 is fixed, the excavation of the ground is restarted and the excavation is performed down to the lower end of the element 14, and then the excavation is temporarily stopped. And
The lower end of the element 14 is also firmly fixed to the ground by the lock bolt 15.

This completes the construction of the first-stage element 14.

(6) Furthermore, the ground is dug down and the element
Drill down to 1m below the bottom edge of 14. (See Figure 6). The second vertical hole 1 is excavated just below the element 14 just constructed (see FIG. 5). Excavation of vertical hole 1
The procedure is the same as in (1) (see Figures 20 and 21). At the beginning of excavation of the vertical hole 1 in the second stage, the element 14 directly above
Occasionally, it becomes impossible to set the cutter head of the Chen Saw excavator directly under the element 14, but
In that case, excavation will be started from the inside of the element 14 and gradually proceeded directly below the element 14.
(See Figure 22). (7) Build the reinforcing bar 2 in the vertical hole 1 in the same manner as in the case of (2), and insert the release material 7 inside the reinforcing bar 2.

(8) Concrete 8 is filled in the vertical hole 1 by the same method as in the case of (3) and fully cured.

(9) The gap A between the upper and lower elements 14 and 14 is lined with reinforced concrete to form the upper and lower elements 14 and 1.
Repeat 4 (see Figure 7). In the lining of the gap A, the reinforcing bars 2 are arranged in the gap A while being joined to the reinforcing bars 2 protruding from the lower end of the upper element 14 and the upper end of the lower element 14, and the form 16 is formed on the surface of the gap A. Is set and the concrete 8 is placed in the form 16.

(10) Excavate the concrete 8, that is, the inside of the second stage element 14 in the same manner as in the case of (4).

(11) In the same way as in (5), the element
Fix 14 to the surrounding ground.

In the same manner, the steps (6) to (11) are repeated in the same manner, and the elements 14 of the third and fourth stages are arranged in the depth direction.
The whole earth retaining wall is constructed by sequentially constructing and connecting (see FIGS. 6 to 8).

[0031]

Since the present invention is configured as described above, it has the following effects.

The earth retaining wall is not constructed over the entire length from the beginning, but is divided into a plurality of elements in the depth direction, and the divided elements are sequentially constructed in the depth direction.
The vertical holes for building each element may be relatively shallow and do not need to be deep as they are connected to build the entire earth retaining wall. Therefore, the excavator can be a small one that is easy to handle, and it is possible to proceed with the work while checking the construction status such as the excavation status of the vertical hole and the concrete pouring condition, thus enabling safe and reliable construction. It is.

Further, by adding a required number of elements in the depth direction, it is possible to construct an earth retaining wall of an arbitrary depth, and it is possible to sufficiently cope with the construction of deep underground structures.

Since each stage element is constructed vertically and the vertical earth retaining wall in which the upper and lower elements are connected and integrated as a whole is constructed, there is no waste in the excavation area, and
The mechanical strength is also high, and the earth retaining wall can be made thinner.

[Brief description of drawings]

FIG. 1 is a sectional view of the ground showing a method of excavating a vertical hole by a chain saw excavator.

FIG. 2 is a sectional view of the ground showing a concrete pouring method.

FIG. 3 is a sectional view of the ground showing a method of excavating the ground.

FIG. 4 is a cross-sectional view of the ground showing a method of installing a lock bolt.

FIG. 5 is a sectional view of the ground showing a method of excavating a vertical hole.

FIG. 6 is a cross-sectional view of the ground showing an element under construction.

FIG. 7 is a sectional view of the ground showing an element in the middle of construction.

FIG. 8 is a cross-sectional view of the ground showing an element under construction.

FIG. 9 is a perspective view showing a part of the earth retaining wall which is circularly constructed and is being constructed.

FIG. 10 is a perspective view showing a part of the earth retaining wall during construction.

FIG. 11 is a front view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 12 is a plan view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 13 is a front view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 14 is a plan view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 15 is a partial perspective view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 16 is a partial perspective view of a reinforcing bar showing a reinforcing bar arrangement method.

FIG. 17 is a partial plan view of a vertical hole showing a method for placing split concrete.

FIG. 18 is a partial plan view of a vertical hole showing a method for placing split concrete.

FIG. 19 is a partial plan view of a vertical hole showing a method for placing split concrete.

FIG. 20 is a perspective view showing a method of excavating a vertical hole by using a chain saw excavator.

FIG. 21 is a cross-sectional view showing a method of excavating a vertical hole by using a chainsaw excavator.

FIG. 22 is a plan view showing a method for excavating a vertical hole by a Chen Saw excavator.

FIG. 23 is a partial perspective view of an earth retaining wall showing a reinforcing bar reinforcing method.

FIG. 24 is a partial perspective view of an earth retaining wall showing a concrete pouring method using a concrete pump.

[Explanation of symbols]

1 ... Vertical hole, 2 ... Reinforcing bar, 3 ... Male joint, 4 ... Female joint, 6 ...
Prop, 7 ... Release material, 8 ... Concrete, 9 ... Concrete pump, 10 ... Packer, 11 ... Reaction force receiving, 12 ... Rocking pipe, 13 ... Connecting bar, 14 ... Concrete wall body (element), 15 ... Rock bolt, 16… Formwork.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tadashi Yoshikawa 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) Reference JP-A-3-206213 (JP, A)

Claims (1)

(57) [Claims] 1. An earth retaining wall to be constructed is vertically divided into a plurality of stages of elements, and (A) excavation of a narrow vertical hole in the ground, inside a vertical hole with a release material interposed on the inner ground side. Of the first reinforced (top) element in the order of forming a reinforced concrete earth retaining wall, excavating the ground inside the earth retaining wall, and fixing the earth retaining wall to the ground by rock bolts, (B) The ground inside the first-stage element is further excavated beyond the lower end of the element, and then the narrow vertical hole of the second stage is excavated just below the first-stage element,
Constructing a second stage element in the same manner as the process,
(C) A step of filling the gap between the lower end of the first-stage element and the upper end of the second-stage element with a reinforcing bar concrete to connect both elements, and (D), (B) and (C) steps are repeated to further lower element The process of constructing / connecting the elements, and, in connection with the deep and deep excavation, which is characterized in that the upper and lower ends of the elements of each stage are connected and the lower stage elements are sequentially constructed in the depth direction to construct the whole earth retaining wall. Earth retaining method.