JPH1077630A - Earth retaining wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to simplify a temporary work by placing each element in two directions resistible against the load in the vertical and horizontal directions and placing each element like a semi-circle shaped up when viewed on the plane and connecting each element by way of joints. SOLUTION: Each element 1a is formed so that it may resist against both loads in the vertical and horizontal directions. During construction, A plurality of elements 1a are provided side by side substantially in the shape of a semi-circle so that they may run along the outer profile of a spiral-shaped slipway which is a semi-circle when viewed on the plane and which serves as an entrance of an underground parking space, for example. Furthermore, each of the elements 1a is connected mutually by way of a joint in structure capable of transmitting the load in the horizontal direction and a in-face shearing force. Since rigidity not only in the vertical direction but also in the horizontal direction can be secured and a self-sustaining ability is excellent and support work such as strut can be omitted due to this construction compared with ordinal continuous underground wall, it is possible to contrive to simplify temporary work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth retaining wall provided at the time of excavating a ground.

[0002]

2. Description of the Related Art As is well known, a retaining wall is a temporary structure whose main purpose is to prevent collapse of the surrounding ground during ground excavation work, and a sheet pile, a steel sheet pile, a steel pipe sheet pile, or the like is driven into the ground. Conventionally, a relatively simple structure having a simple structure is generally used.However, since the retaining wall having such a structure is not sufficiently self-supporting, an earth anchor for reinforcing the self-reliability is provided, or the retaining wall is provided. It was necessary to provide a plurality of cutting beams inside the wall to support it.

[0003] In recent years, when large-scale and deep excavation is performed, a continuous underground wall is constructed underground as a permanent underground frame, and is used as a retaining wall during construction. It is also widely practiced. The continuous underground wall is constructed by excavating the ground in a groove shape, placing a reinforced cage inside it and casting concrete, and at the time of construction, the preceding elements are constructed at intervals. ,
Most commonly, a procedure is adopted in which succeeding elements are constructed between the preceding elements to make them all continuous.

[0004] Such a continuous underground wall is excellent in self-sustainability, so that if it is used as an earth retaining wall, the cutting beam can be greatly simplified, and if it is used together with the reverse striking method, it can be installed permanently. The floor slabs and beams can be made to function as cutting beams, so that temporary construction can be greatly simplified.

[0005]

Incidentally, the earth retaining wall formed by the continuous underground wall is usually provided in a flat shape, but sometimes it is desired to form a curved earth retaining wall. For example, when a spiral ramp is provided as a self-propelled approach / exit road in an underground parking lot, the ground may be excavated in a semi-circular shape corresponding to the planar shape of the ramp. It is conceivable to construct a continuous underground wall in a semicircular shape corresponding to the plane shape of the lane and use it as a retaining wall.

In such a case, the floor slab provided inside the retaining wall is desired to function as a cutting beam. However, the floor slab becomes a spiral-shaped ramp, which is constructed by a reverse striking method. The use of beams is difficult and impractical.
Therefore, as in the case of conventional earth retaining walls, such semi-circular earth retaining walls have to be provided with earth anchors or a large number of temporary cutting beams, so that temporary construction cannot be simplified much. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a structure suitable for application when a retaining wall comprising a continuous underground wall is provided in a substantially semicircular shape in plan view. .

[0008]

The earth retaining wall of the present invention is a two-way plate capable of withstanding both vertical and horizontal loads on each of the elements constituting the continuous underground wall. It is characterized in that it is constructed in such a manner that it is arranged in a substantially semicircular shape as viewed from the outside and the elements are connected to each other via a joint capable of transmitting a horizontal load and an in-plane shearing force.

According to the present invention, a continuous underground wall is provided in a semicircular shape and used as an earth retaining wall. A plurality of elements are provided in a continuous form as in the case of an ordinary planar continuous underground wall. However, in the continuous underground wall according to the present invention, each element is a two-way version, and since these elements are structurally connected in a horizontal direction via a joint portion, a normal continuous underground wall is used. Compared to the wall, it can secure sufficient rigidity not only in the vertical direction but also in the horizontal direction and is excellent in self-sustainability, so it is possible to omit the support work such as cutting beams and simplify temporary construction work Can be achieved sufficiently.

[0010]

1 and 2 show a retaining wall 1 according to an embodiment of the present invention. The retaining wall 1 of the present embodiment is applied to a portion of a spiral inclined road having a semicircular shape in plan view, which is an entrance / exit path of an underground parking lot, and is used as an outer wall of the underground parking lot and also as a retaining wall. Is provided as a semicircular continuous underground wall bulging outward from the planar continuous underground wall 2 to be formed. The retaining wall 1 of the present embodiment is constructed by arranging a plurality of elements 1a in a substantially semicircular shape so as to follow the outer contour of a ramp, but each of the elements 1a is arranged in a vertical direction and a horizontal direction. Each of the elements 1a is structurally connected to each other via a joint 3 having a structure capable of transmitting a horizontal load and an in-plane shearing force. I have. The structure of the joint portion 3 is arbitrary as long as it can transmit a load in the horizontal direction.

The cross section of the earth retaining wall 1 in the vertical direction and the horizontal direction is determined by the following elasticity analysis. In addition, the construction step 1 shows a state where the first stage excavation (up to GL-6.3 m in this example) is performed,
Similarly, construction step 2 is the second stage excavation (GL-1
0.6m), construction step 3 shows the state of excavation at the third stage (GL-15.7m), construction step 4 shows the state of excavation at the fourth stage (GL-26.1m). . (A) Analytical model (see FIG. 3) A continuous underground wall to be constructed as the retaining wall 1 is modeled as a three-dimensional shell model. The ground is an elastic spring, and the shoring is a point or linear spring, and the arrangement of the spring is changed for each construction step. (B) Load (see FIG. 4) The cross section is calculated by the increment of the load according to the construction step, and is added to the sectional force up to the previous step to obtain the sectional force for each construction step. (C) Cross-sectional calculation The load in the above (b) is applied to the analytical model in the above (a), and the cross-sectional calculations in the vertical and horizontal directions are calculated with respect to the cross-sectional force obtained by performing the three-dimensional elastic sequential stress analysis. Do. That is, the vertical section is determined from the vertical bending moment, the out-of-plane shear force, and the axial force, and the horizontal section is determined from the horizontal bending moment, the out-of-plane shear force, and the axial force.
Inspection of in-plane shearing force is also performed separately.

The retaining wall 1 having the above-described structure includes
a is a two-way version and each element 1a is structurally continuous in the horizontal direction by the joint portion 3, so that the earth retaining wall composed of a normal continuous underground wall, ie, each element 1a Compared with the conventional general underground wall, which is a directional version and they are merely arranged, the independence as a retaining wall has been significantly improved, and for this reason, It is possible to greatly simplify the shoring work and to reduce the thickness thereof. Therefore, in the present embodiment, when excavating the inside, it is not necessary to make the floor of each floor function as a cutting beam as in the related art. For example, as shown in FIG.
It is enough to use the 3F floor slab 4 as a cutting beam,
As a result, simplification of the construction can be realized and the construction period can be shortened.

[0013]

As described above, in the earth retaining wall of the present invention, each element constituting the continuous underground wall is a two-way version capable of withstanding both vertical and horizontal loads. It is constructed in such a manner that it is arranged in a substantially semicircular shape in plan view and each element is connected to each other via a joint capable of transmitting a horizontal load and an in-plane shear force. Compared to the continuous underground wall, the rigidity not only in the vertical direction but also in the horizontal direction can be sufficiently ensured, and the self-sustainability is excellent. Therefore, it is possible to omit the support work such as a cutting beam. Therefore, the present invention is particularly suitable for application to, for example, an inclined road portion in an underground parking lot. In such a case, temporary construction work can be sufficiently simplified, and the construction period can be reduced and the construction cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an earth retaining wall according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a diagram showing an analysis model when determining a cross section of the earth retaining wall.

FIG. 4 is a diagram showing the same load.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Earth retaining wall 1a Element 3 Joint part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazunori Toda 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation

Claims (1)

[Claims] An element constituting a continuous underground wall is a two-way plate capable of withstanding loads in both a vertical direction and a horizontal direction, and the elements are arranged so as to form a substantially semicircular shape in plan view. A retaining wall, wherein the elements are constructed in a state where the elements are connected to each other via a joint capable of transmitting a horizontal load and an in-plane shear force.