JP2001348873A - Land slide protection wall support structure and construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide land slide protection wall support structure suppressing the length of a tension material short even in the case an anchor layer exists in a deep position. SOLUTION: An anchor body 13c is disposed in the improved ground 11 formed in the ground 17 around the outer periphery of land slide protection wall 12. A tension material 13b is extended from the anchor body to the land slide protection wall, and an anchor head part 13a is anchored to the land slide protection wall to constitute this land slide protection wall support structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for a retaining wall.

[0002]

2. Description of the Related Art A mountain retaining wall 12 is constructed deeper than a root bottom 16 and receives earth pressure from the ground above the active collapse line 15. For example, FIG.
Are provided with anchors 14, 15 or cutting beams. However, when the plane to be excavated is irregular, it is difficult to effectively arrange the girder, so that it is often supported by the anchor.

The anchors 14 and 15 have anchoring members 14c and 15c buried in a fixing layer 18 and tension members 14b and 15b made of steel stranded wires or the like are attached to the anchoring members 14c and 15c.
c to the retaining wall 12, and anchor heads 14 a and 15 a are fixed to the retaining wall 12.

[0004]

However, in the above-mentioned conventional support structure, if the anchoring layer 18 for burying the anchors 14c, 15c is located at a deep position, very long tensile members 14b, 15b are required. However, there is a disadvantage that the material cost of the tensile members 14b and 15b also increases. In addition, very long tensile members 14b, 1
5b, the anchor bodies 14c and 15c are
From the outside, and in this case, there is a problem that the construction cannot be performed without the permission of the adjacent landowner.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a problem that the length of the tensile member is reduced even if the fixing layer is located at a deep position. It is an object of the present invention to provide a support structure of a retaining wall which can be used.

[0006]

According to the present invention, there is provided a ground improvement body formed in the ground around the retaining wall, an anchor disposed in the ground improvement, and extending from the anchor to the retaining wall. A tensioning member to which a tension is introduced, and an anchor head for fixing an end portion of the tensioning member to the mountain retaining wall to hold the tension introduced to the tensioning member, the support structure for the mountain retaining wall is provided. Provided.

In the support structure for a retaining wall according to the present invention, the ground improvement body may be one which can provide a sufficient reaction force to the retaining wall via a tensile member or an anchor head by embedding an anchor body. For example, the structure and construction method are not particularly limited.For example, a mechanical stirring method of excavating the ground with a drill shaft member of an earth auger and mixing and stirring with the soil at a predetermined depth while discharging cement milk from the tip of the drill shaft member. The ground may be constructed by a construction method, or the ground may be drilled with a boring rod, the ground ground in the area to be improved crushed with high-pressure air or water at a predetermined depth, and the cut portion may be filled with the improved material or mixed with the cut soil It may be constructed by a high-pressure injection method.

Further, in the present invention, a step of forming a ground improvement body in the ground around the retaining wall, drilling a hole from the root cutting side of the retaining wall toward the ground improvement body, and extending a tensile material into the hole. Forming an anchor body in the ground improvement body, introducing tension into the tension member, and providing an anchor head at an end of the tension member to maintain the tension of the tension member. Fixing to the retaining wall, and a method for supporting the retaining wall.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. FIG. 1 is a cross-sectional view showing a support structure of a retaining wall according to the present invention. In FIG. 1, a retaining structure 10 for a retaining wall is composed of a ground improvement body 11 constructed on a ground 17 outside a retaining wall 12 and inside a site boundary line 15, and an anchor 13. An anchor body 13c buried in the ground improvement body 11, a tension member 13b made of a stranded wire or the like of a steel material which is extended from the anchor body 13c at an angle (θ ≦ 45 °) to the retaining wall 12 and tension is introduced. An anchor head 1 for fixing the end of the tension member 13b to the retaining wall 12 to maintain the tension introduced into the tension member 13b
3a.

Here, the ground improvement body 11 is located at a position relatively close and shallow to the retaining wall 12 in order to shorten the length of the tension member 13b in the anchor 13 to facilitate construction and reduce material costs. The anchor body 13c is preferably provided only at a place where the anchor body 13c is buried, and its strength may be any as long as the anchor body 13c can obtain a sufficient adhesive force. For example, the uniaxial compressive strength is about 20N. / Cm ² or more.

In the support structure 10 of the retaining wall, in addition to the anchor 13, an anchor 14 c is attached to the fixing layer 18.
May be used together, and which anchor to use in which location may be determined by whether or not the anchor body can be embedded in the anchoring layer 18 inside the site boundary 15. .

In the support structure of the retaining wall 12 having the above-described structure, the earth pressure acting on the retaining wall 12 from the ground 17 is transmitted as a tensile force to the tension member 13b via the anchor head 13a, and further the anchoring force is transmitted from the tension member 13b to the anchor. It reaches the body 13c. At this time, the anchor body 13c is
To the ground improvement body 11
Since the anchor 13 itself is formed with a relatively large compressive strength, the anchor 13 can obtain a sufficient reaction force in the anchor body 13c, and the retaining wall 12 is securely supported.

Next, a method for supporting the retaining wall will be described. In the method of supporting a mountain retaining wall, first, an underground wall is constructed around an excavation plane in a construction site, and this is used as a mountain retaining wall 12, and before or after or simultaneously with this mountain retaining wall construction step, an outer peripheral ground of the mountain retaining wall 12 is constructed. Ground improvement body 1 at a predetermined depth of 17
Form one. This ground improvement body 11 is, for example, ground 1
It can be constructed by a deep mixing method in which the ground is improved by stirring and mixing the local soil and cement milk at a predetermined depth of 7.

Next, after constructing the ground improvement body 11, while excavating the excavation plane surrounded by the retaining wall 12, the anchor 13,
14 are provided. That is, a through hole (not shown) is formed in the retaining wall 12, and the outer peripheral ground 17 is drilled from the through hole toward the ground improvement body 11, and when the hole reaches the ground improvement body 11, the anchor body 13c is removed. A grout material made of cement or the like is filled into the holes to form the holes. Then, the tension member 13b is inserted into the grout material and extended to the root cutting side of the retaining wall 12, and when the grout material is sufficiently solidified, the tension member 13b
And an end of the tension member 13b is fixed by the anchor head 13a. By providing the anchors 13 at all of the predetermined locations by the above steps and providing the anchors 14 as needed, a support structure for the retaining wall can be constructed.

[0015]

According to the present invention, the anchor body is buried in the ground improvement body constructed in the ground around the retaining wall, so that the anchor body is securely held in the ground improvement body. A reaction force is obtained, and even if the anchoring layer is present at a deep position, if the ground improvement body is provided relatively close to the retaining wall and at a shallow position, the tensile material of the anchor can be relatively long. Since it can be kept short, the support structure of the retaining wall can be easily constructed, and the material cost of the tensile member is also suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a support structure for a retaining wall according to the present invention.

FIG. 2 is a cross-sectional view illustrating a conventional retaining structure for a mountain retaining wall.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Support structure of retaining wall 11 Ground improvement body 12 Retaining wall 13 Anchor 13a Anchor head 13b Tensile material 13c Anchor body 15 Site boundary line 17 Peripheral ground

Claims (2)

[Claims] 1. A ground improvement body formed in the ground around a retaining wall, an anchor disposed in the ground improvement, and a tension member extending from the anchor to the retaining wall and receiving tension. And an anchor head for fixing an end portion of the tensile member to the retaining wall in order to maintain the tension introduced into the tension member, and a support structure for the retaining wall. 2. A step of forming a ground improvement body in the ground around an outer periphery of a retaining wall, drilling a hole from the root cutting side of the retaining wall toward the ground improvement body, and extending a tensile material into the hole. A step of forming an anchor body in the ground improvement body, a step of applying tension to the tension member, and providing an anchor head at an end of the tension member to maintain the tension of the tension member; A method of supporting a mountain retaining wall, including a step of fixing to a mountain.