JPS61134432A - Building method for landslide protection wall - Google Patents

Abstract

PURPOSE:To efficiently drain water in a banking layer, by a method wherein a watert permeably sheet is laid to the back of a block and plural water permeable sheets are horizontally laid in a banking layer to guide gap water in the banking layer to the surfaces of retaining wall blocks. CONSTITUTION:A water permeable sheet 1 is laid on a foundation surface G to the back of a bse concrete 10, and base concrete blocks 2 are laid in one row on the base concrete 10. Water permeable form panels 3 are framed upright to the back of the blocks 2, and concrete D is placed to form the blocks 2 into an integral structure. A banking layer G1 is formed on the water permeable sheet 1, which is laid on the banking layer G1 and in concrete for blocks 2. The blocks 2 re built by following the same procedures to form a banking layer at the backs of the blocks. This process enables promotion of darainage of the banking laeyr and reduction of the earth pressure of the banking layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a retaining wall method for constructing earth retaining walls to prevent collapse of slopes such as embankments and excavated earth.

[B] Conventional technology: As a slope protection method, pile up stones, concrete blocks, etc. in a row! 11 Methods of constructing walls are well known.

For example, taking a retaining wall made of concrete blocks as an example, as shown in FIG. 6, the retaining blocks 2 are piled up and the retaining concrete D is filled.

this! Stack the chestnut stones B spatially that occur on the back side of the IWA.

Next, the back surface of the chestnut stone B is filled with earth and sand C for backfilling, and the earth and sand are compacted.

[Explanation] Problems to be Solved by the Invention The following problems exist in the above-described conventional horizontal construction method for retaining walls.

(1) Hold it! Tonosho, which affects IA, is affected by the quality of compaction of backfilling soil.

However, if you try to compact it forcibly, the earth and sand and blocks will protrude forward, tilting towards IIWAtfiII,
In the end, there is a risk of it falling over, so it is difficult to compact it sufficiently.

(2) When the soil C contains moisture due to rainfall, the IM per unit volume increases, and the soil load applied to the magic WA increases rapidly.

In particular, if such a high moisture content state is subjected to earthquakes or vibrations from moving vehicles, there is a very high risk that the earth and sand will liquefy and the embankment will collapse.

(3) Earth and sand C cannot be compacted sufficiently using machines, so there is a risk of serious accidents such as road collapse and tilting of structures.

(4) Since sufficient compaction of the earth and sand C cannot be expected, the slope of the retaining wall A must be formed to be gentler as the slope becomes a self-supporting factor.

Support! ! The gentler the slope of A, the more! The area of I wall increases, and the effective land area decreases accordingly.

Furthermore, the construction period is extended and the amount of materials consumed increases, making it uneconomical.

(5) As the above-mentioned improvement method, construction methods such as terre alme exist.

This is a construction method in which metal strips or rods are extended almost horizontally behind the board and buried underground.

However, because water collects around the metal strips and rods buried underground, the frictional resistance between them and the soil decreases.

Therefore, metal bands, bars, etc. buried underground cannot be expected to have much frictional resistance against earth and sand.

The present invention was made to solve the same problem, and prevents the collapse of the retaining wall by suppressing the settling of the bedding material and reducing the earth pressure applied to the retaining wall. The purpose is to provide an earth retaining wall construction method.

[C] Means for Solving the Problems The present invention consists of a water permeable sheet connected at one end to the back side of the 111 wall that protects the slope, approximately horizontally ff1EIL, and earth and sand embanked on this sheet being compacted. While building the embankment layer,
It relates to a technical means characterized by forming a waterway by interposing a water-permeable material between the sheets between each embankment layer, and connecting one end of the waterway to WIN to enable drainage outside the retaining wall. .

C2] Example Hereinafter, a method for constructing a retaining wall made of concrete blocks, which is an example of the present invention, will be explained with reference to the drawings.

(1) Water-permeable sheet used in the present invention (Fig. 1) The water-permeable sheet 1 is a nonwoven fabric or the like formed by three-dimensionally intertwining continuous long fibers.

This water-permeable sheet 1 has corrosion resistance and moderate strength,
In addition, polyamide, polyethylene,
Of course, it is also possible to use a fibrous material whose main component is thermoplastic IIN such as polypropylene or polystyrene, or a mesh or string-like material thereof, or a metal material thereof.

This water-permeable sheet 1 can be rolled into a roll and cut to a predetermined length on site, or it can be cut into a predetermined length and then transported to the site. It can be used.

(2) Laying of water-permeable sheet As shown in FIG. 2, base concrete 10 is placed.

On the foundation surface G on the back side of this base concrete 10, the water permeable sheet 1 of the above structure is laid over the entire surface.

At this time, the retaining wall side end (J! end) of each water permeable sheet 1 is the III! Align it in position.

(3) Stacking of blocks Concrete blocks (hereinafter referred to as "blocks 2") are arranged horizontally in a row on the base concrete 10.

On the back side of the block 2, a water permeable panel 3 made of a water permeable material having the same water permeability as the water permeable sheet 1 is installed laterally.

Then, concrete D is placed in a space surrounded by the blocks 2 and the water-permeable panels 3, so that each block 2 has an integral structure.

The water-permeable panel 3 used for pouring the concrete D can not only be used as a formwork when pouring concrete, but can also function as a water passage and a heat insulating material, as will be described later.

Therefore, the water permeable panel 3 has rigidity, water permeability, and heat insulation properties, and for example, a nonwoven fabric can be attached to the back of the frame board, and its height can be made to be approximately the same height as the thickness of the embankment layer for one span to be constructed. I can do it.

Concrete D is placed in the space formed on the back of 10 Tsuku 2.
As a result of placing the water-permeable sheet 1, one end of the water-permeable sheet 1 is buried in the poured concrete D and becomes integrated with the retaining wall A.

(4) II Earth work Transport the earth and sand onto the top surface of the permeable sheet 1, spread it on an almost horizontal surface, and compact it thoroughly using a compactor, first embankment layer G
form 1.

(5) Laying a water-permeable sheet (Fig. 3) When the first embankment layer G1 is completed, a new water-permeable sheet 1 is laid on its upper surface.

The base end of this water-permeable sheet 1 is buried in poured concrete D.

Next, embankment is performed on the first embankment layer G1 with the water-permeable sheet 1 interposed therebetween, thereby forming a second embankment layer G2.

As a result, the permeable sheets 1 laid on the upper and lower surfaces of the first embankment layer G1 are connected to the permeable panels 3 and have continuity as a waterway.

The present invention provides a water permeable seal l-1 interposed between each embankment layer.
One of the characteristics is that it provides continuity of water permeability to at.

(6) Drainage treatment (Fig. 3) As in the previous method, a drainage pipe 4 made of a PVC pipe or the like with both ends open is installed to penetrate the block 2 for the purpose of drainage.

Then, the water collection port of the drain pipe 4 is connected to the water permeable sheet 1 or the water permeable panel 3.

In this way, in parallel with the construction of blocks 2 one after another, the water-permeable sheet 1 with continuity is interposed between the embankment layers and the filling work is proceeded, and III! Build A.

[Other Examples] (1) In addition to the method of laying the water-permeable sheet 1 according to the above embodiment, it is also possible to adopt a laying method as shown in FIG. 4.

That is, one end of the water-permeable sheet 1 is folded back to ensure a sufficient length, and the folded part T is buried in the II wall A as in the previous embodiment, but the free part 112 of the folded water-permeable sheet 1 is It is rolled up until the next embankment layer is constructed, and when the embankment is completed, it is laid over the top of this embankment layer so as to wrap around the front of the embankment.

Therefore, two water-permeable sheets 1 are laid laterally in front of each embankment layer.

Furthermore, since the front surface of each embankment layer is surrounded by the permeable sheet 1, the stability of the embankment and retaining wall is further improved.

(2) In addition, a method of laying the water-permeable sheet 1 as shown in FIG. 5 is also considered.

In other words, the permeable sheet 1 laid on the top surface of each embankment layer
This method involves laying a new water-permeable sheet on top to prevent the embankment layer from protruding to the front.

In this laying method, the τ end 13 of the new permeable sheet is laid over the top surface of the lower sheet of the embankment layer, and the other end 12 is laid over the top surface of this embankment layer, so the front side of the embankment is simply covered. If multiple sheets are laid at appropriate intervals in the horizontal direction on one embankment layer, a higher drainage effect can be obtained than when there is only one permeable panel connecting each permeable sheet 11ffi. be able to.

In addition, permeable sheets 1 are scattered almost horizontally on the same embankment layer.
It is also possible to use it by dividing it into two parts: a front sheet that connects to the retaining wIA and a rear sheet that covers most of the embankment layer.

[E] Effects Since the present invention is as explained above, the following effects can be expected.

Even if a large amount of water infiltrates in a short period of time due to rainfall, etc., the permeable sheets will efficiently drain the water and prevent excessive pore water pressure from occurring in the backfilling soil.

Therefore, it is possible to prevent a decrease in the shear strength of the earth and sand, to reduce the amount of dirt, and to prevent the liquefaction of the earth and sand.

(2) Good drainage treatment within the loaded soil increases the shearing force in the soil, making it easier for the m-wall to stand on its own, and in general, the barrier between the permeable sheet and the soil. Nomoll
! Resistance increases and tonosho can be significantly reduced.

(311 Excess water from the earth and sand for filling is removed, and sufficient compaction of the earth and sand for filling is possible, so it is possible to prevent settling of the earth and sand for filling after completion.

(4) Since the tonosho can be significantly reduced, there is no need to worry about the barrier wall tipping over or collapsing even if the slope angle of the W wall is built at a steep slope.

(5) By laying a water-permeable sheet or a water-permeable panel, it is possible to omit the stone placed on the back of the block.

(6) If the water-permeable material on the back side of the retaining wall has heat insulating properties, freezing damage to mu can be prevented.

[Brief explanation of the drawing]

Figure 1: Perspective explanatory diagram of III wall Figure 2.3: Cross-sectional explanatory diagram of construction method Figure 4.5: Cross-sectional explanatory diagram of other water-permeable sheet installation methods

Claims (1)

[Claims] A water-permeable sheet with one end connected to the back of a retaining wall that protects the slope is laid almost horizontally, and earth and sand piled up on this sheet are compacted to construct an embankment layer, and each This retaining wall construction method is characterized by forming a waterway by interposing a permeable material between the sheets between the embankment layers, and connecting one end of the waterway to the retaining wall so that water can drain outside the retaining wall.