JPS637421A - Construction of soil structure - Google Patents

Abstract

PURPOSE:To construct a strong soil structure having excellent workability by a method in which, geotextiles having an expandible synthetic resin block on their ends are laid on the ground, and soil is spread over the textiles and compacted in a repeating manner. CONSTITUTION:A water-permeable geotextile 1 of polyethylene sheet is laid on the ground A, an expanded styrol block 2 is placed on the geotextile 1, and one end of the geotextile 1 is folded into the block 2. Soil 3 is spread over the block 2 and compacted to form a soil layer 4. These processes are repeated, and the soil layers 4 are laminated in such a way as to extend the ends of the geotextiles 1 in lapped formed in vertical or slant directions to construct the soil structure D. The soil structure D which can be stably and strongly constructed even on soft ground can thus be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for constructing earth structures such as embankments and retaining walls.
In particular, the present invention relates to a method for constructing an earth structure that has excellent workability and can be constructed stably and firmly even on soft ground.

[Conventional technology]

The following methods are conventionally known as methods for constructing earthen structures such as embankments and retaining walls.

(A) A geotextile is laid, earth and sand is poured out on top of it, compacted, and one end of the free end of the geotextile is bent, and earth and sand is stuffed into it to form a soil layer, and this process is repeated while A method of building earth structures by stacking soil layers.

This method utilizes the advantage that geotextile is integrated with the soil layer and is difficult to pull out, so it can be used even on cohesive soil with low frictional force.

(B) A method of constructing an earth structure included in the wall member by connecting an appropriate wall member to the free end side of the earth structure of (A) above.

(C) A method of building an embankment by piling up foamable synthetic resin blocks such as styrofoam.

[Problem that the invention seeks to solve]

However, in the above-mentioned known technology, method (A) involves bending one free end of the geotextile and stacking it while encasing earth and sand, which makes the work extremely difficult and has poor workability. The geotextile itself is easily deformed, making it impossible to construct large earthen structures such as retaining walls into precise shapes.

In addition, in method (B), when clayey soil is used as the earth and sand,
The compression of the earth structure increases, and as a result, pressure concentrates at the joints with the wall members, making them more likely to break, making it impossible for geotextiles to demonstrate their applicability to clayey soil.

Furthermore, in method (C), the foamed synthetic resin block is lightweight, so it easily collapses in an earthquake, and since it is lighter than water, it floats under the groundwater table, making it extremely impractical. .

An object of the present invention is to provide a method for constructing an earth structure that can form a strong earth structure that has excellent workability and is difficult to destroy, and that improves the drawbacks of the above-mentioned known techniques.

[Means for solving problems]

In order to achieve the above-mentioned object, according to the present invention, a geotextile having a foamable synthetic resin block held at its end is laid on the ground such that the portion where the block is held is located on the free end side, The method is characterized by sprinkling earth and sand on top of this, rolling it to form a soil layer, and repeating this process to stack the soil layers.

The geotextile mentioned above is a synthetic resin fiber, grid, nonwoven fabric, woven fabric, sheet, or a composite material thereof.

Further, the foamable synthetic resin block is a block that can be compressed under load, such as a foamed polystyrene block. For example, as a styrofoam block, the density is 20+r/r
r+, compressive strength is 1 k+r r/cnl at 5% deformation
A moderate amount is best.

In the present invention, first, the above-mentioned geotextile is laid on the ground. At this time, a foamable synthetic resin block is held at the end of the geotextile.

Moreover, this geotextile is laid so that the retained part of the block is located on the free end side.

This will be explained in detail below using the accompanying drawings.

1 and 2 are cross-sectional views showing how a foamable synthetic resin block is held at the end of a geotextile, and A is the ground. A water-permeable geotextile 1 made of, for example, a polyethylene sheet is laid on the ground A, and a Styrofoam block 2 with a diameter of 1.0 m, a thickness of 0.5 m, and a length of 3.0 m is placed on top of this. As shown in the figure, one end 1a of the geotextile 1 is folded back and a styrene foam block 2 is wrapped inside, and then earth and sand 3 is poured out on top of the block 2 and is compacted to form a soil layer 4. At this time, the portion where the expanded polystyrene block 2 is held becomes the end portion B of the geotextile 1. Moreover, one side C of this end B becomes a free end of the obtained earth structure as described later. Note that the styrofoam 2 may be held by sprinkling earth and sand 3 onto the geotextile 1 and rolling it, and then folding one end 1a of the geotextile 1 over the earth and sand 3, as shown in the second figure.

Next, the above-described steps are repeated to stack the soil layers to construct the soil structure according to the present invention. FIGS. 3 and 4 are cross-sectional views showing an example of an earth structure constructed according to the present invention. In FIG. 3, an earth structure is constructed by stacking soil layers 4 such that the end portions B of the geotextile 1 holding the Styrofoam 2 are vertically overlapping and extending. Therefore, in this case, each soil layer 4.4...
The free ends C, C, etc. of 4 also extend in the vertical direction and form the wall surface E of the earth structure. Although not shown, another protective wall made of concrete or the like may be further formed on the wall E in order to protect the wall E from ultraviolet rays or the like.

In addition, in the present invention, it is also possible to construct an earth structure by stacking the soil layers 4 so that the end portion B of the geotextile l holding the expanded polystyrene 2 extends diagonally upward as shown in the fourth figure. In this case, in order to protect the free ends C, .

[Effect]

(1) A foamable synthetic resin block is held at the end of the geotextile, and the shape of the free end of the earth structure is maintained accurately by the action of this block. If this block does not exist, it becomes impossible to construct an earth structure in an accurate shape as in the conventional technique (A) described above.

(2) Since the foamable synthetic resin block is surrounded and held by geotextile, it is extremely strong. Therefore, unlike the prior art (B) mentioned above, the connecting portion with the wall member is not destroyed.

(3) Since the foamable synthetic resin block is flexible and compressible, and is held in a manner surrounded by geotextile, it can freely deform to adapt to compression.
For this reason, no special stress concentration acts, and an earth structure that is difficult to break and is easily constructed can be constructed.

(4) If the block is rigid like in the past, it is difficult to deform, so the sliding surface is at a position of lOa as shown in Figure 5, but in the present invention, a flexible foamable synthetic resin block is used. Therefore, the slip plane is at position 10. Therefore, the length of the geotextile 1 on the back of the block can be shorter than in the case of a rigid block, and the geotextile 1 only needs to be laid down to the fixed area (b), as shown in Figure 5, so that the loose area ( The part a) will be fixed with the L′ part of the geotextile,
There is no fear that the aforementioned blocks will collapse due to earthquakes, groundwater, etc., and are integrated into the entire earth structure.

(5) As shown in FIG. 6, the earth structure beam according to the present invention exhibits an earth retaining effect that resists back earth pressure (c) due to the heavy body. In addition, in conventional earth structures, the ground pressure P at the front of the earth retaining area is extremely large as shown in Figure 6, and for this reason, it was only applicable to foundations with a large ground bearing capacity.However, the present invention is lightweight and flexible. Since a foamable synthetic resin block is used, the ground pressure at the front of the earth structure is P', which is small, and it can be applied even on soft foundation ground.

(6) When a wall panel is installed as an exterior on the free end of the earth structure according to the present invention, the earth structure and the exterior can be constructed separately and independently, so structural damage does not occur and workability is improved. It's easy. Therefore, the exterior is simply an aesthetic effect,
Alternatively, it is sufficient if it has the effect of preventing deterioration caused by ultraviolet rays.

〔Effect of the invention〕

As described above, the present invention uses a geotextile with foamable synthetic resin blocks held at its ends as a reinforcing material, lays it on the ground, spreads out earth and sand, and forms a soil layer by rolling. As mentioned above, it is possible to build a strong earth structure that has excellent construction properties and is difficult to destroy.

[Brief explanation of the drawing]

FIGS. 1 and 2 each show a specific example of the soil layer according to the present invention, FIGS. 3 and 4 each show a specific example of the soil structure constructed according to the present invention, and FIG. FIG. 6 is an explanatory diagram showing the surface etc., and FIG. 6 is an explanatory diagram showing the load state of the earth structure of the present invention. 1... Geotextile, 2... Styrofoam, 3... Sediment, 4... Soil layer, A.
...Ground, B...End, C...Free end, D
...Earth structure, E...Wall patent applicant Reinforced Earth Engineering Co., Ltd.

Claims (1)

[Claims] A geotextile with a foamable synthetic resin block held at the end is laid on the ground so that the part where the block is held is located on the free end side, and earth and sand are spread on top of this and compacted to form a soil layer. A method for constructing an earth structure, characterized in that the soil layers are stacked by repeating this step.