JPH0657741A - Earth retaining wall - Google Patents

Abstract

(57) [Summary] [Purpose] A low-cost self-sustaining retaining wall that does not require beams or the like, has excellent workability in underground construction, and can be easily installed and removed. [Structure] The H-shaped steel core material head inserted into the soil cement column that constitutes the mountain retaining wall is connected by a horizontal member, and an out-cable type unbonded PC steel wire is placed along the surface of the horizontal member. Pre-stress is introduced by fixing the both ends to the natural ground through the end portions of the mountain retaining wall or the intermediate fixing blocks, by inserting a nikka material and extending it in an arc shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retaining wall suitable for underground construction and underground construction where the ground is soft and the groundwater level is high.

[0002]

In the earth retaining method, the groundwater level is usually high and water stopping is often required. In such a case, a columnar body made of soil cement or the like is used as a waterproofing mountain retaining wall, and a supporting structure in which a girder is hung is adopted. In the case of the supporting method, when constructing the skeleton of the underground part, since the beams and the like are laid in a grid pattern, the efficiency of work such as lifting, bar arrangement, and concrete placing is significantly reduced. For this reason, it is necessary to have a self-supporting mountain clasp without a beam.

However, since the self-supporting earth retaining member has no beam, the resistance element is only the earth retaining wall, and the out-of-plane displacement due to earth pressure becomes extremely large. When the root cutting depth is large on soft ground, it may reach several tens of centimeters.

In such a case, a method of simply increasing the number of rows of the soil cement columnar body to increase the rigidity is simple, but when the site is not available, the required number of rows cannot be constructed. In addition, a great burden is imposed in terms of cost and labor.

The present invention has been made in view of the above circumstances. Its purpose is to propose a mountain retaining wall that can maintain and control out-of-plane displacement within a permissible range by a simple means without using a cutting beam or the like.

[0006]

In this mountain retaining wall, a head of a steel frame core material inserted into a column body constituting the mountain retaining wall is connected with a horizontal member, and an out-cable type tension member is connected to the horizontal member. It is characterized in that a pre-stress is introduced by fixing both ends to the natural ground by inserting a lumber along the surface and putting it in a substantially arc shape.

[0007]

In the mountain retaining wall configured as described above, the out-of-plane deformation can be freely adjusted and the displacement can be maintained within an allowable range by the arc shape of the tension material stretched in an arc shape and the tension amount of the prestress introduced. It will be possible.

Out-cable type unbonded PC
Since a tension material such as steel wire is used, it is easy to install and can be easily removed after use.

Since the tension member is stretched along the horizontal member that connects the heads of the mountain retaining walls, it does not become an obstacle to the underground construction work, and the construction efficiency can be significantly improved compared with the truss support type. .

When the root cutting depth is large on soft ground, displacement control can be performed more easily and more reliably than the truss support type.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show an earth retaining wall of a square shape in plan view, which is constructed by constructing a soil cement columnar body 3 in which a core material of H-shaped steel 2 is inserted into a ground 1. In addition, 4 is a root cutting bottom in FIG.

In this mountain retaining wall, a horizontal member of the channel steel 5 is fixedly connected to the wall surface side of the heads of the plurality of H-shaped steels 2 of the core material to connect the heads. An out-cable type unbonded PC steel wire 6 is arranged along the surface of the channel steel 5. In this example, the rectangular long side portion of the mountain retaining wall was divided at the center and two PC steel wires 6 were used.

Both ends of the PC steel wire 6 are fixed at the ends of the mountain retaining wall and the center of the side on the long side, and at both ends on the short side. A filler material 7 is inserted between the PC steel wire 6 and the channel steel 5, and the PC steel wire 6 is stretched in a substantially arc shape.

Three reaction cement columns 8 of soil cement are built outside the central portion of the long side of the mountain retaining wall to form a column array 3 and a reaction column 8.
The intermediate fixing block 9 is made by pouring concrete on the head of the head, and the end fixing block 10 is made by pouring concrete on the end of the head as well.

As shown in FIGS. 3 and 4, fixing tools 11 are attached to the ends of the PC steel wire 6, respectively, and the ends or the intermediate fixing blocks 10 and 9 are used as reaction points, and they are pulled from the other end to give a predetermined pre-fix. Introduce stress.

In the end fixing block 10, two column arrays 3 of columns orthogonal to each other cancel out the prestress reaction force, and the intermediate fixing block 9 is integrated with the reaction column to function as a prestress reaction point. , PC steel wire ends can be firmly fixed to the ground.

In this embodiment, the long side portion of the mountain retaining wall having a long width is divided into two and two PC steel wires are used, but the mountain retaining wall having a short width is not necessary. In order to give a large out-of-plane displacement suppressing force to the mountain retaining wall having a long width, the radius of curvature of the PC steel wire in the arc shape must be made small, which is not preferable because the central portion of the PC steel wire is overhanged.

[0018]

As described above, the present invention has the following effects.

Since this mountain retaining wall does not require a crossbeam, the construction efficiency of underground construction can be significantly improved.

Since an out-cable type PC steel wire or the like is used as a self-supporting wall, installation and removal are easy, and cost reduction can be achieved.

It can also be applied to a retaining wall on a small site.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a mountain retaining wall according to an embodiment.

FIG. 2 is a plan view of the mountain retaining wall of the embodiment.

FIG. 3 is a plan view showing a partial cross section of an end fixing portion of the mountain retaining wall.

FIG. 4 is a plan view showing a partial cross section of an intermediate fixing portion of the mountain retaining wall.

[Explanation of symbols]

1 ... Ground, 2 ... H-section steel, 3 ... Column body, 4 ... Root cutting bottom, 5
… Channel steel, 6… Unbonded PC steel wire, 7… Heating material, 8…
Reaction force column, 9 ... Intermediate fixing block, 10 ... End fixing block, 11 ... Fixing tool.

Claims (1)

[Claims] 1. A head portion of a steel core material inserted into a column body forming a mountain retaining wall is connected by a horizontal member, and an out-cable type tension member is provided along the surface of the horizontal member with an interposing material. A mountain retaining wall characterized by being inserted and stretched in a substantially arc shape, with both ends fixed to the ground and prestressed.