JPH11217823A - Earth retaining method in cut and cover tunneling work of ground and steel sheet pile used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the promotion of working efficiency for an earth retaining method in a cut and cover tunneling site and the prevention of a ground collapse accident. SOLUTION: Steel sheet piles B used for earth retaining in a ground cut and cover tunneling site are so formed that two sheet pile members 1a and 1b are connected to the front and rear to combine them with each other in a slidable manner in the vertical direction (up and down directions). The steel sheet piles are erected at a stage excavating shallowly a cut and cover tunneling groove A to carry out the initial earth retaining work, and then, the sheet pile member 1b on the rear side is pushed forward with the excavtion of the cut and cover tunneling groove A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth retaining method for digging a road or the like and a lightweight steel sheet pile used for the method.

[0002]

2. Description of the Related Art In general, when laying gas, water and sewage, burying underground cables, or repairing or replacing existing ones, the ground is cut open, and at that time, along the side walls of the cut grooves. In order to prevent the collapse of the ground, the earth is stopped by lightweight steel sheet piles.

[0003] In this type of construction, the depth of the cut groove is usually two.
Conventionally, as shown in FIG. 11, first, the entire excavation groove A having a predetermined depth is excavated and formed, as shown in FIG.
Thereafter, light steel sheet piles B, B are laid side by side along the groove wall, a flared material is attached, and a cutting beam is erected.

[0004]

According to the conventional earth retaining method in this kind of construction, as described above, since the earth retaining work is performed after excavating the open cut groove to a predetermined depth, the construction is simple, but the construction is simple. There is a drawback that the danger that the ground collapses before excavating to some extent and building steel sheet piles cannot be avoided. Moreover, in the construction on soft ground, the excavation work must be performed after the steel sheet pile has been driven, and the construction becomes large-scale and requires a great deal of cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. A lightweight steel sheet pile used as an earth retaining material is obtained by combining a plurality of sheet pile members so as to be slidable up and down. By extending the steel sheet pile as the excavation digging progresses, the collapse of the ground is prevented, and the safety of workers and the improvement of work efficiency are aimed at.

[0006]

The construction of the present invention for attaining the above object will be described with reference to the drawings corresponding to the embodiments. , 1b are slidably overlapped in the longitudinal direction of the steel sheet pile B, and the steel sheet pile B is erected along the groove wall at an early stage of excavation where the cut groove A is formed shallowly. The erection material 12 and the cutting beam 13 are erected and earth retaining is performed. Then, as the excavation groove A is excavated, the steel sheet pile B
, One of the sheet pile members 1b is pushed down.

Further, the steel sheet pile according to the second aspect is formed in a vertically long band shape by a steel plate, and the engaging grooves 4 run vertically on the back sides of both outer portions.
One sheet pile member 1a provided with a sheet metal and a steel sheet have a shape similar to the above sheet pile member 1a, engaging strips 7 are provided on both sides thereof, and a hook member 8 for depressing is provided at the lower end part. And the other sheet pile member 1b is joined to the back surface of one sheet pile member 1a, and the engaging groove 4 and the engaging strip 7 are engaged with each other.
a and 1b are combined so as to be slidable in the vertical direction without being separated from each other.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the method of the present invention, and FIGS. 4 to 10 show examples of a lightweight steel sheet pile (hereinafter referred to as a steel sheet pile) used in the method of the present invention. is there.

First, an embodiment of a steel sheet pile used in the method of the present invention will be described. 4 to FIG.
Is a steel sheet pile, which is formed by two sheet pile members 1a and 1b. One sheet pile member 1a is formed in a strip shape by bending a vertically long steel plate in the width direction, and for example, as shown in the drawing, a ridge having a mountain-shaped cross section protruding toward the front side (one surface side) at the center in the width direction. 2 runs vertically, and on both sides the back side (ground side)
The recesses 3 and 3 having a trapezoidal shape are formed in the direction, and the engagement grooves 4 and 4 which are bent in an arc shape inward from the back side and run vertically are provided on both outer sides following the recess. It has become.

Further, the other sheet pile member 1b is longer than or equal to the one sheet pile member 1a, and is made to be in contact with the back surface of the one sheet pile member 1a.
a, which has concave portions 6 and 6 on both sides of the ridge 5 and curved engagement ridges 7 and 7 which engage in the engagement groove 4 on both outer portions.
And the sheet pile member 1b
At the lower end portion, a hook member 8 for depressing, which protrudes over almost the entire width of the front surface side, is provided.

The other sheet pile member 1b is joined to the back surface of one sheet pile member 1a, and engagement strips 7,
7 into the engagement grooves 4 and 4, and the one sheet pile member 1a
Are combined (polymerized) so that they can slide up and down (vertically) with each other. Thereby, the steel sheet pile B used in the method of the present invention is obtained. In this steel sheet pile B, the hook member 8 of the other sheet pile member 1b is brought into contact with the lower end of one sheet pile member 1a so that the two sheet pile members 1a and 1b overlap each other in a reduced state. Thus, the upper end of the other sheet pile member 1b can be freely expanded and contracted until it is in an extended state in which the sheet pile member 1b is overlapped, so that it can be used.

8 to 10 show another embodiment of the steel sheet pile. This embodiment is different from the previous embodiment in that one of the sheet pile members 1a has recesses 3, 3 thereof.
Is provided with a slit 10 extending from the upper end to the vicinity of the lower end along the longitudinal direction, and the other sheet pile portion 1b is engaged with the slit portion 10 in the upper portion of the depressions 6, 6. A hook 11 having a T-shaped cross section is provided to protrude. Other configurations are the same as those in the previous embodiment, and the description thereof will be omitted.

In each of the above embodiments, two sheet pile members 1 are used.
a and 1b are overlapped and engaged,
The number of piles of the sheet pile members may be three or more. Further, the cross-sectional shape of the sheet pile member is not limited to that of each embodiment, and various shapes can be adopted.

The earth retaining method of the present invention is performed using the steel sheet pile B as described above. In the ground, an open groove A having a required width is initially excavated to a depth at which the ground does not collapse. In particular, in the case of a non-soft ground, the depth is preferably about 1 m corresponding to the length of the reduced steel sheet pile B. As shown in FIG. 1 and FIG. 2, a steel sheet pile B in a reduced form in contact with the two groove walls a, a in the cut groove A formed at the initial stage.
Of the sheet pile members 1a, 1a of the sheet pile members 1a, 1a are connected to each other by the protruding material 12,
A bridge 13 is erected between the flared uprights 12 on both sides to provide an early stop.

Thereafter, as shown in FIG. 3, the ground below the bottom of the cut groove A is dug down, and with the excavation,
The other sheet pile member 1b on the back side is slid with respect to the one sheet pile member 1a by hitting the down hook 8 or the like to follow the depth of the cut groove A. Thereby, the groove walls a, a of the cut groove A are connected to one of the sheet pile members 1.
a and the other sheet pile member 1b extending downward by sliding, the earth retaining is performed. Therefore, the collapse of the ground can be prevented in almost all the steps of the excavation work, and the safety of the worker working in the excavation groove is secured.

[0016]

As described above, according to the earth retaining method of the present invention, a steel sheet pile that can be extended up and down is used to perform an early earth embankment in the initial stage of the shallow excavation, After that, the steel sheet pile was extended as the trench was dug down, so that in the construction of the trench, the collapse of the trench wall was prevented throughout the entire process from the start of the excavation to the end of the construction. In addition to ensuring the safety of construction, the efficiency of work associated with preventing the collapse of the ground can be improved, and the construction period can be shortened.

Further, the steel sheet pile used in the earth retaining method of the present invention slides without overlapping because both sheet pile members are overlapped on the front and back, so that the sheet pile is easy to handle and the length when the sheet pile is reduced can be shortened. Therefore, it is convenient for transportation.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a state of an initial embankment in an embodiment of the method of the present invention.

FIG. 2 is a plan sectional view of the same part.

FIG. 3 is a side sectional view showing a state where the steel sheet pile is extended.

FIG. 4 is a plan view showing one embodiment of a steel sheet pile.

FIG. 5 is a sectional side view of the same.

FIG. 6 is a perspective view of the same part.

FIG. 7 is a plan view showing the sheet pile members separated from each other.

FIG. 8 is a plan view showing another embodiment of the steel sheet pile.

FIG. 9 is a sectional side view of the same.

FIG. 10 is a plan sectional view showing the sheet pile members separated from each other.

FIG. 11 is a side sectional view showing an embodiment of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS A Opening groove B Steel sheet pile 1a, 1b Sheet pile member 2, 5 Ridge 3, 6 Depression 4 Engagement groove 7 Engagement line 8 Depression hook member 10 Slit 11 Detachment prevention hook 12 Belly raised material 13 Cut beam

Claims (2)

[Claims] 1. A steel sheet pile formed by stacking a plurality of sheet pile members so as to be slidable in the longitudinal direction of the sheet pile member, and in an initial stage of excavation in which an open groove is formed shallowly, the steel sheet pile is moved along a groove wall. Erecting, erection material and cutting beams are installed and earth retaining is performed, and then, as the excavation groove is excavated, one of the sheet pile members of the steel sheet pile is pushed down, and Earth retaining method in digging work. 2. A sheet pile member having a vertically elongated band shape made of a steel plate and having engagement grooves running vertically on the back surfaces of both outer portions,
The sheet pile has a shape similar to that of the sheet pile member, engagement strips are provided on both sides thereof, and the other sheet pile member is provided with a hook member for depressing at a lower end portion. The other sheet pile member is joined to the back surface of the sheet pile member, the engagement groove and the engagement strip are engaged with each other, and the sheet pile members are combined so as to be slidable in the vertical direction without being separated from each other. Steel sheet pile used in earth retaining method in ground excavation work.