JPH05112930A - Construction method of underground continuous wall - Google Patents

Abstract

PURPOSE:To make it possible to surely position an excavator and secure a vertical attitude thereof in the case a longitudinal hole for a succeeding element is excavated between two preceding elements and to enable stable excavation while securing an accurate cutting line accordingly. CONSTITUTION:A reinforced cage 2 having parting members 3 and 3 on both ends in the direction of a construction joint is erected in a longitudinal hole 1 for a preceding element, the outsides of the parting members 3 and 3 are filled with gravel or crushed stone 7, and concrete 4 is placed to the other part to construct preceding elements 8. After that, a longitudinal hole 9 for a succeeding element is excavated between the two preceding elements 8 by an excavator 10, a reinforced cage is erected into the longitudinal hole 9 for the succeeding element, and the concrete 4 is placed to construct the succeeding element 9 together with the preceding elements 8 as a unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground continuous wall by constructing a plurality of leading elements (walls) in the ground and integrally constructing a trailing element between the leading elements and the leading element. The present invention relates to a method of constructing an underground continuous wall for building a building.

[0002]

2. Description of the Related Art Generally, underground continuous walls are constructed as earth retaining walls and foundations of structures. However, the following methods are widely used today. Has been.

First, a plurality of preceding elements (walls) forming a part of the underground continuous wall are constructed in the ground in such a manner that the length of one element is separated. These preceding elements are constructed by first drilling a vertical hole, building a reinforced cage in the vertical hole, and then placing concrete. When the preceding element can be constructed, the adjacent left and right two preceding elements are excavated and the vertical hole for the succeeding element is excavated.

In parallel with the excavation of the vertical hole, the end face of the preceding element in the splicing direction is cut and removed by a predetermined size (usually about 10 cm on one end face).

The reason why the end face of the preceding element is cut and removed is to remove the slime adhering to the end face and to so-called roughen the joint surface. After that, as in the case of the preceding element, a reinforcing steel cage is built in the vertical hole for this succeeding element and the latter element is constructed integrally with the preceding element by placing concrete to construct the entire underground wall. It is to be constructed.

[0006]

By the way, in the above conventional method, when excavating a vertical hole for a trailing element between two adjacent left and right leading elements, the excavator is placed between the left and right leading elements. Just set it in the middle part,
The end face of the leading element is cut in parallel with the excavation of the vertical hole for the trailing element. However, since the leading element is made of concrete, especially in the initial stage of excavation, that is, the upper end face portions of the two leading elements on the left and right sides of the excavator. When the excavator drill hangs up and attempts to start excavation and cutting of the end face of the element, the drill of the excavator does not bite smoothly into the hard concrete, causing a so-called escape. For this reason, there are many cases where not only the correct cutting line cannot be secured due to the positional deviation, but also the excavator lacks stability and causes an unbalanced load.

The present invention has been proposed in order to solve the above-mentioned conventional problems. When excavating a vertical hole for a trailing element between two adjacent left and right leading elements, Positioning and stable holding can be ensured,
An object of the present invention is to provide a method for constructing a continuous underground wall which enables stable excavation while maintaining an accurate cutting line.

[0008]

A method of constructing an underground continuous wall according to the present invention divides an underground continuous wall to be constructed into a plurality of elements in the construction direction, and first, for the preceding element. Vertical holes are drilled at regular intervals, concrete is placed in the vertical holes to construct a preceding element, and then, while cutting the end face of the preceding element in the joining direction between these preceding elements, for the succeeding element. In the method for constructing a continuous underground wall by drilling a vertical hole and placing concrete in the vertical hole for the subsequent element to construct a backward element integrally with the preceding element, A reinforcing bar cage with a partition member at the end in the direction of splicing is built in the vertical hole for the element, and the space outside this partition member is filled with gravel or crushed stone, and the other part is filled with coke. A cleat is cast to construct a leading element, and then a vertical hole for a trailing element is drilled by an excavator between two adjacent left and right leading elements, and a reinforcing bar is placed in the vertical hole for the trailing element. The above object is achieved by constructing a car, placing concrete, constructing a trailing element integrally with the preceding element and constructing a continuous underground wall.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for constructing a continuous underground wall according to the present invention will be described below in order with reference to FIGS.

First, the vertical hole 1 for the preceding element is excavated. The required number of vertical holes 1 is excavated while securing a space for approximately one element.

Subsequently, the reinforcing cage 2 is built in each vertical hole 1 for the preceding element (see FIG. 1). Rebar cage 2
Is assembled by arranging the required amount of reinforcing bars vertically and horizontally according to the scale of the underground continuous wall to be constructed, and partition members 3 made of iron plates or the like are attached to both ends of the upper part in the width direction ( (See Figures 7,8,9).

The partition member 3 has a thickness of 6 to 12 mm and a length of 3 to 4 m, for example, when an iron plate is used, and has a width substantially equal to the width of the vertical hole 1 for the preceding element. It is used. The partition member 3 is buried in the concrete.

Subsequently, concrete 4 is placed in the vertical hole 1.
(See Figure 1). For placing concrete 4,
The tremie pipe 5 is used so that the concrete can be prevented from being separated and dense concrete can be obtained. still,
The tremie pipe 5 is promptly removed after the concrete is poured.

When the concrete 4 reaches the lower end of the partition member 3, the space 6 on the outside of the left and right partition member 3 is filled with an easily excavable material such as gravel and crushed stone 7 to the ground surface while the left and right partition members 3, 3 are filled. Concrete 4 is continuously cast to the ground surface only inside the ground (see Fig. 2). In this way the individual predecessor elements 8 are constructed (see FIG. 3).

In this case, the adjacent left and right preceding elements 8,
The interval L ₁ between the partition members 3, 3 of 8 is slightly larger than the width W of the vertical hole 9 for the trailing element (excavation width of the excavator) (about 10 to 50 mm), and the left and right preceding elements 8, 8 The distance L ₂ between the partition members 3 of the left and right preceding elements 8,8 is
It is narrowed by about twice the width S of the left and right space 6 (about 220 to 300 mm) than the distance L ₁ between the three (see FIGS. 4 and 5).

When the construction of each preceding element 8 is completed, the excavator is placed in the center between the two preceding elements 8 on the left and right.
10 is installed and the excavation of the vertical hole 9 for the trailing element is started (see FIG. 5).

When excavating the vertical hole 9, in the initial stage, it is not necessary to cut the left and right preceding elements 8,8, and in order to excavate the gravel and the crushed stone 6 which are easy to excavate, the excavation is smoothly advanced to the lower end of the partition member 3. And after that,
The original excavation is performed while cutting the left and right preceding elements 8 and 8 end faces.

In such a case, the distance L ₁ between the partition members 3, 3 of the left and right preceding elements 8, 8 is determined by the width W (L ₁ > of the vertical hole 9).
Since it is substantially equal to L ₂ ), even if the cutting of the preceding element 8 is started, no positional deviation occurs and a correct cutting line can be secured.

Incidentally, a backhoe, a clamshell or the like other than the excavator 10 may be used for the initial stage excavation to the lower end of the partition member, and the excavator 10 may be used for the subsequent excavations.

When the vertical hole 9 has been excavated, as in the case of the preceding element 8, a reinforcing bar cage (not shown) is built in the vertical hole 9 and the concrete 4 is placed to move the trailing element 11 to the preceding element 8. (See FIG. 6). In addition, the succeeding element 11 is intended to shorten the construction period by performing it at a plurality of locations in parallel.

FIG. 10 shows a case where a curved underground continuous wall such as a cylindrical underground structure is constructed. In this case, the left and right partition members 3, 3 of the preceding element 8
According to the curvature of the underground continuous wall to be constructed, it is attached obliquely to the end of the reinforcing bar cage 2 to correspond to the curvature of the underground continuous wall to be constructed.

[0022]

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

When excavating a vertical hole for a trailing element between adjacent left and right preceding elements by an excavator, the excavation at the initial stage where the position of the excavator is determined does not involve cutting the preceding element and is easy to cut gravel. Since excavation of rocks and crushed stones, excavation of the trailing element in the initial stage can be performed extremely smoothly.

Further, since the left and right partition members reliably position and maintain the posture of the excavator in the initial stage,
The excavator can be prevented from running away and stable excavation can be performed while maintaining an accurate excavation line.

Further, in the space outside the partition member,
Since the irregular shape members such as gravel and crushed stone are filled instead of installing the fixed members such as the spacer box, it is possible to freely change the shape of the joining part between the preceding element and the succeeding element. By giving an arbitrary curvature to the underground continuous wall, the underground continuous wall with an arbitrary curved shape can be easily constructed.

[Brief description of drawings]

FIG. 1 is a front view of a preceding element showing the construction method of the present invention at the beginning of construction.

FIG. 2 is a front view of the preceding element showing the construction method of the present invention, just before the completion of construction.

FIG. 3 is a front view of a preceding element constructed by the construction method of the present invention.

FIG. 4 is a front view of adjacent left and right preceding elements constructed by the construction method of the present invention.

FIG. 5 is a front view showing a construction method of the present invention when excavating a vertical hole for a trailing element.

FIG. 6 is a front view of a leading element and a trailing element constructed by the construction method of the present invention.

FIG. 7 is a front view of a reinforcing bar cage used in the construction method of the present invention.

8 is a plan view of the reinforcing cage shown in FIG. 7. FIG.

FIG. 9 is a plan view showing an installed state of a reinforcing bar cage.

FIG. 10 is a plan view of a preceding element showing another construction method of the present invention.

[Explanation of symbols]

1 ... Vertical hole for preceding element, 2 ... Reinforcing cage, 3 ... Partition member, 4 ... Concrete, 5 ... Tremy tube, 6 ... Space part, 7 ... Gravel and crushed stone, 8 ... Leading element, 9 ... For trailing element Vertical hole, 10 ... excavator, 11 ... trailing element.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Nagase 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Within Kashima Construction Co., Ltd. (72) Inventor Kazuo Suzuki 1-2-2 Moto-Akasaka, Minato-ku, Tokyo No. 7 Kashima Construction Co., Ltd.

Claims (1)

[Claims] 1. An underground continuous wall to be constructed is divided into a plurality of elements in the construction direction, first, vertical holes for preceding elements are excavated at regular intervals, and concrete is placed in the vertical holes. To construct a leading element, and then to drill a vertical hole for a trailing element while cutting the end face of the leading element in the splicing direction between these leading elements, and to place concrete in the vertical hole for the trailing element. In the method of constructing a continuous underground wall by constructing a trailing element integrally with the preceding element to construct a continuous underground wall, a reinforcing bar having a partition member at the end of the vertical hole for the preceding element in the joining direction. Build a car, fill the space outside the partition member with gravel or crushed stone that is easy to excavate, and place concrete in the other part to build the preceding element. Then, a vertical hole for a trailing element is drilled by an excavator between two adjacent left and right leading elements, and a reinforcing bar cage is built in the vertical hole for the trailing element to place concrete and the preceding element is added. A method for constructing a continuous underground wall, characterized by constructing a trailing element integrally with the above.