JPH052773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a slope retaining wall construction method in which a retaining wall is constructed by piling up precast concrete blocks on a slope obtained by excavating an embankment or a slope.

(Prior art) Conventionally, when constructing a road such as a mountain road by excavating the middle of a slope in steps, or when widening an already constructed road by excavating the original slope on the mountain side, etc. In order to prevent slopes created by excavating original slopes from collapsing, retaining walls are constructed to cover the slopes.

Conventional retaining walls of this type include a framework made of concrete blocks assembled in a lattice pattern, and a structure made by stacking gravity-type concrete blocks. A method has been developed to do so.

In addition, in order to safely cover steep slopes and prevent collapse, a construction method has been developed in which underground anchors are constructed prior to constructing a retaining wall and the retaining wall is supported by these anchors.

(Problems to be Solved by the Invention) In conventional construction of retaining walls, the original slope is excavated to form a slope with a predetermined slope, and then the walls are built up sequentially from the bottom of the slope. Therefore, if the ground is weak when forming a slope, landslides will occur and it will not be possible to make the slope higher than a certain level.

For this reason, in the past, it was necessary to provide a plurality of slopes in a step-like manner by providing a horizontal portion in the middle of the slope, which caused the problem that the covered area became large.

The present invention has been made in view of the above-mentioned conventional problems, and aims to provide a method for constructing a slope retaining wall that can safely construct a steeply sloped and long slope retaining wall.

(Means for Solving the Problems) The features of the slope retaining wall construction method of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose are as follows:
In a slope retaining wall construction method, a retaining wall is constructed by excavating an original slope into a slope with a required angle, piling up precast concrete retaining wall blocks along the slope, and covering the surface of the slope. Divide the slope on which you are going to construct a slope into sections of a certain height, excavate one section on the upper side to form a slope of a specified slope, and place underground anchors at regular intervals on the lower edge of the section. A horizontal girder-shaped intermediate foundation is supported by the underground anchors, and retaining wall blocks are stacked one after another on the intermediate foundation to construct one section of retaining wall. The next step is to excavate the slope of the slope and construct a retaining wall downward one section at a time in the same manner as described above, thereby creating a retaining wall that is continuous vertically.

In addition, in the above construction method, vertically continuous cast-in-place concrete pillars are formed between horizontally adjacent retaining wall blocks that are stacked one after another, and prestressed steel is installed in continuity between the pillars and the intermediate foundation. It may be inserted and prestressed.

(Function) In the slope retaining wall construction method of the present invention, retaining walls are constructed one section at a time from the top without excavating the lower parts of the original slope in a stable state, and each section's retaining wall is Because it is supported by a girder-shaped intermediate foundation anchored to the ground with underground anchors, the area where the retaining wall has been constructed is stable and there is no risk of landslides. In this way, excavate one section at a time from the top,
Since it reaches the bottom while being stabilized, a continuous retaining wall can be safely constructed even on steep slopes.

In addition, by forming vertically continuous columnar parts between horizontally adjacent retaining wall blocks, and applying prestress to this column by continuing with the girder parts, the structure is constructed by the columnar parts and the intermediate foundation. The grid-like frame is anchored to the ground by underground anchors, increasing stability.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

First, at the design stage, as shown in Fig. 1, the slope 2 to be formed by excavating the original slope 1 is set,
The slope is divided vertically into a plurality of sections _H1 to _H3 . The inclination of the slope 2 and the length of one section at this time are determined in consideration of the stability of the ground.

Next, as shown in Fig. 2, the original slope 1 is excavated from the uppermost part of the slope 2 by the first section H ₁ minute.
A slope 2 having a predetermined slope is formed. Then, an anchor hole 3 is drilled into the ground at the bottom of the slope 2, cement paste is injected, and anchor concrete 4 is placed in the hole.
An underground anchor 6 is constructed by inserting an anchor tension member 5 made of PC steel. Next, the anchor tensile member 5 of this underground anchor 6 is penetrated and cast-in-place concrete or precast concrete is used to construct a first intermediate foundation 7 in the shape of a girder extending in the horizontal direction.
Install a.

Next, the lower end of the PC steel material 8 made of an unbonded cable is penetrated through this first intermediate foundation 7a,
Arrange multiple pieces vertically. This PC steel material 8 is inserted in a number corresponding to the number of sections H ₁ , H _{2 .} . . in one tube, and one of them is fixed to the first intermediate foundation 7a.

Next, as shown in FIG. 3, retaining wall blocks 9, 9, . . . made of precast concrete are successively stacked along the slope while being supported on the first intermediate foundation 7a. This retaining wall block 9 has side walls 10, 10 and a rear wall 11 arranged in a U-shape as shown in FIGS. It has a soil receiving space with an open upper surface, and window holes 14 and 15 are opened in the rear wall 11 and the bottom plate 13. Also, both side walls 1
As shown in FIG. 11, on the outside of 0 and 10, there are half groove-like portions 16, which are joined side by side to form a vertically dovetail groove-like groove 17 on the back surface.
16 are formed. And the first intermediate foundation 7
When stacking on top a, each PC steel material 8 is arranged so as to be inserted into the groove 17.

In this way, each retaining wall block 9 is divided into the first section.
H After stacking for ₁ minute, put a precast concrete top plate 18 on top of it, pass each PC steel material 8 through it and stretch it straight, and add cement mortar 19 (No. 11) into the groove 17. (shown in the figure) is injected, and after waiting for it to solidify, the PC steel material 8 whose lower end is fixed to the first intermediate foundation 7a described above is tensioned from above the top plate 18 to apply prestress. Note that the other PC steel materials 8 may be prevented from adhering to the cement mortar 19 by extending the lower end side downward, or by moving them up and down before the cement mortar 19 solidifies.

After constructing the retaining wall of the first section _H1 in this way,
As shown in FIG. 4, the slope 1 of the second section _H2 below is excavated, an underground anchor 6 is constructed in the same way as in the first section, and the second intermediate foundation 7b is supported by the underground anchor 6.
Set up.

Then, it was not established in the first section _H1 .
Insert the PC steel material 8 into the second intermediate foundation 7b, fix the lower end of one of them, and stack each retaining wall block 9 to the bottom of the first intermediate foundation 7a in such a position that it is inserted into the groove 17. (As shown in Figure 5). After that, cement mortar 19 is injected into the groove 17, and after waiting for it to solidify, the PC steel material 8 whose lower end is fixed to the second intermediate foundation 7b is tensioned from above the top plate 18.
Apply prestress.

If each section has multiple stages, retaining walls are constructed in sequence for each section in the same way.

In the third section _H3 at the bottom, as shown in Figure 6, after excavating the original slope 1 in the same manner as described above, the bottom part of the slope 2 is made of precast concrete or cast-in-place concrete. After installing the foundation 20 and fixing the lower end of the prestressing steel material 8 thereto, stacking retaining wall blocks 9 as shown in FIG. Tense and give prestress. After constructing the retaining walls of all the sections _H1 to _H3 in this way, the soil receiving space of each retaining wall block 9 is filled with earth and sand, and vegetation is grown in the earth and sand.

(Effect of the invention) As mentioned above, the slope retaining wall construction method of the present invention has the following effects:
By constructing a retaining wall using retaining wall blocks supported one section at a time by underground anchors from the upper part of the original slope, the original slope on the lower side remains in a stable state without being excavated, and the upper side remains as a retaining wall. The structure is stabilized by underground anchors, and as a result, even on steep slopes, it is possible to construct a continuous retaining wall over a wide area without causing landslides.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIGS.
Fig. 7 is a sectional view of the retaining wall construction process according to the method of the present invention, Fig. 8 is a plan view of the retaining wall block, Fig. 9 is a side view of the same, and Fig. 10 is a sectional view taken along line A-A in Fig. 8. ,
FIG. 11 is a partially enlarged cross-sectional view of the retaining wall. H ₁ to _{H 3} ... section, 1 ... original slope, 2 ... slope, 6, 20 ... underground anchor, 7a, 7b ...
Intermediate foundation, 8...PC steel material, 9... Retaining wall block, 17... Concave groove, 19... Top plate, 20... Bottom foundation.

Claims (1)

[Claims] 1. A slope retaining system that covers the surface of an original slope by excavating an original slope into a slope with a necessary angle and stacking blocks for a retaining wall made of precast concrete along the slope. In the wall construction method, the slope on which the retaining wall is to be constructed is divided into sections of a certain height, one section on the upper side is excavated to form a slope of a specified slope, and the lower edge of the section is set at a certain height. An underground anchor is constructed at each interval, a horizontal girder-shaped intermediate foundation is supported by the underground anchor, and retaining wall blocks are stacked one after another on the intermediate foundation to construct one section of retaining wall. Then, the next section of the sloped surface under the intermediate foundation is excavated and a retaining wall is constructed downward one section at a time in the same manner as described above to form a continuous vertical retaining wall. How to build a slope retaining wall. 2 Form vertically continuous cast-in-place concrete columns between horizontally adjacent retaining wall blocks that are stacked one after another, insert prestressing steel continuously between the columns and the intermediate foundation, and apply prestress. A slope retaining wall construction method according to claim 1.