JPH07247541A - Method of protecting soil structure during rainfall - Google Patents

Abstract

PURPOSE:To prevent the surface quality of a soil structure from deteriorating, by coating the surface of the soil structure with a water-repellent and air- permeable sheet during rainfall. CONSTITUTION:When a soil structure 1 is covered with a water-repellent and air-permeable sheet 2, rain water becomes surface water 4 flowing on the surface of the sheet and it is drained and vapour 5 is dispersed outward through the clearances of sheet 2. When the soil structure 1 is covered with a laminate material composed of a water-repellent and air-permeable sheet 2 and an air- permeable water absorbent 6, water becomes surface water 4 and it drained and the vapour 5 is dispersed through the clearance of the sheet 2 and the water-absorbing material and the condensed water 7 is absorbed into the water- absorbing material 6. When it is covered with a laminated material of an air- impermeable waterproof sheet 8 and a water-absorbing material 9, rain water becomes surface water and it is drained and the vapour becomes condesate 7 at the underface of the sheet 8 and it is absorbed in the water absorbing material 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of protecting soil structures, particularly the surface of soil structures under construction from rainfall.

[0002]

2. Description of the Related Art In order to protect the surface of a soil structure from rainfall, it is necessary to cover the surface with an impermeable waterproof sheet such as tarpaulin or vinyl sheet to prevent rainwater from penetrating into the soil material. This is a common method used in outdoor stadiums. The same applies to the protection of the earth structure during construction, and it is a common method to cover it with an impermeable waterproof sheet.

[0003]

In the conventional method of simply covering the surface of a soil structure with an impermeable waterproof sheet, rainwater or soil material that has penetrated through the overlapping portions of the impermeable waterproof sheet evaporates as water vapor and becomes insoluble. The soil material absorbs the water condensed on the lower surface of the breathable waterproof sheet again to form a mud. This phenomenon is remarkable in the case of constructing a soil structure, especially when a water-stopping material layer is constructed using a highly water-absorbing material such as bentonite as a soil material. For this reason, after the rain stopped, it was inevitable to scrape off the deteriorated part of the surface of the soil structure and repeat the construction using a new soil material, and the construction would be repeated for each rainfall. Construction will be significantly delayed due to rainfall.

[0004]

The present invention prevents rainwater from entering the soil material during rainfall, and the soil material absorbs water evaporated from the soil material as water vapor and condensed on the lower surface of the protective sheet. The purpose is to prevent or reduce the deterioration of the surface quality of soil structures due to rainfall, and to shorten the construction period.

In order to achieve this object, the impermeable waterproof sheet which is the conventional protective sheet in the present invention is modified or improved.

That is, the invention according to claim 1 of the present invention is a modification of the conventional impermeable waterproof sheet into a water repellent and breathable sheet, and the invention according to claim 2 is the conventional impermeable waterproof sheet. The sheet is modified into a laminate of a water-repellent breathable sheet and a breathable water-absorbing material. The invention according to claim 3 of the present invention is an improvement of the conventional impermeable waterproof sheet by laminating a water absorbing material on the lower surface of the conventional impermeable waterproof sheet. In any case, by modifying or improving the conventional protective sheet, the protective effect during rainfall is greatly improved.

Regarding the protective sheet which is a feature of the present invention,
The invention according to claim 1 will be sequentially described.

The protective sheet used in the invention of claim 1 is a water repellent and breathable sheet. This sheet is a sheet that does not impede the flow of gas such as air and water vapor, but repels or prevents the flow of water.As a typical example, weaving of hydrophobic fibers treated with water repellent so that weaves and stitches are not blocked. A knitted fabric or a non-woven fabric in which short fibers of hydrophobic fibers are bonded to each other while crushing the gaps between the short fibers to some extent and leaving innumerable minute gaps. In the case of a woven or knitted fabric, the weave and the stitches are usually large enough to allow water to permeate through them, but the water is repelled on the surface of the woven or knitted fabric because it is water repellent. In the case of a non-woven fabric, the minute gaps themselves have a size that makes it difficult for water to permeate, and the structure is generally such that the hydrophobicity of the fibers does not allow water to permeate. When the soil structure is covered with this water repellent breathable sheet during rainfall, rainwater is blocked by the water repellent breathable sheet and flows over the sheet, while water vapor evaporated from the soil material passes through the sheet and is released to the outside air. .

The protective sheet used in the invention of claim 2 is a laminate of a water-repellent breathable sheet and a breathable water-absorbing material. The water-repellent breathable sheet is as described above. This is a sheet in which a breathable water-absorbent material is laminated on the lower surface (the surface in contact with the soil material) of this water-repellent breathable sheet. Typical examples of the breathable water-absorbent material to be laminated are ordinary non-woven fabric in which short fibers of hydrophobic fiber are entangled and adhered to each other while keeping the mutual gap as much as possible, non-woven fabric of high water-absorption fiber, and powder particles of high water-absorption resin. A sheet including is included. These breathable water-absorbent materials are partially bonded and laminated on the lower surface of the water-repellent breathable sheet so as not to impair the breathability of the water-repellent breathable sheet. When the soil structure is covered with this laminate during rainfall, rainwater is blocked by the water-repellent breathable sheet and flows over the sheet,
On the other hand, the water vapor evaporated from the soil material passes through the laminate and is diffused to the outside air, and the water condensed on the lower surface of the laminate without being diffused is absorbed and retained by the breathable water absorbing material.

The protective sheet used in the third aspect of the invention is a laminate of an impermeable waterproof sheet and a water absorbing material. A normal tarpaulin or vinyl sheet is used as the impermeable waterproof sheet. This water-impermeable waterproof sheet is a sheet in which a water-absorbing material is laminated on the lower surface (surface contacting the soil material). The water absorbing material may be breathable or not. As an example of the water-absorbing material, other than the above-mentioned breathable water-absorbing material,
Examples include thin cotton-like materials of various fibers, non-woven fabrics, sheets containing bentonite, and the like. These water absorbing materials are appropriately stuck and laminated on the lower surface of the impermeable waterproof sheet. When the soil structure is covered with this laminate during rainfall, rainwater is impeded by the impermeable tarpaulin and flows over the sheet, while condensed water of water vapor evaporated from the soil material is absorbed and retained by the water absorbent material.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing the embodiments.

FIG. 1 is a vertical cross-sectional view of a soil structure covered with a protective sheet used in the present invention when it rains. (A) is a water repellent and breathable sheet, and (b) is a water repellent and breathable sheet. When using a laminate of sheet and breathable water absorbent material,
(C) is a case where a laminate of an impermeable waterproof sheet and a water absorbing material is used.

When the soil structure 1 is covered with the water repellent and air permeable sheet 2 of (a), the rainwater 3 becomes surface water 4 flowing on the surface of the water repellent and air permeable sheet 2 and is drained. The generated water vapor 5 is diffused to the outside through the gaps between the water repellent and air permeable sheet 2.

When the soil structure 1 is covered with the laminate of the water repellent and air permeable sheet 2 and the air permeable and water absorbing material 6 of (b), rain water 3
Is discharged as surface water 4 flowing on the surface of the water-repellent and air-permeable sheet 2, and most of the water vapor generated from the earth structure 1 remains in the gap between the air-permeable and water-absorbing material 6 and the gap between the water-repellent and air-permeable sheet 2. Through which it is released to the outside as water vapor 5,
The water that has not been completely diffused and condensed on the lower surface of the water-repellent breathable sheet 2 to become water 7 is absorbed by the breathable water-absorbing material 6.

When the soil structure 1 is covered with the laminate of the impermeable waterproof sheet 8 and the water absorbing material 9 of (c), the rainwater 3 becomes surface water 4 flowing on the surface of the impermeable waterproof sheet 8. The water vapor discharged and generated from the earth structure 1 is condensed on the lower surface of the impermeable waterproof sheet 8 to become water 7 which is absorbed by the water absorbing material 9.

In the present invention, when the soil structure is covered with the protective sheet, a method of laying it on the surface of the earth structure 1 while unwinding the rolled protective sheet is usually adopted. A large value is preferable. For this reason, the protective sheet is connected in the vertical and horizontal directions in advance and stored in a rolled form, and is laid when it rains. Usually, the earth structure 1 cannot be covered with one roll of the protective sheet, so that it is necessary to connect the ends of the protective sheet to each other to prevent rainwater from entering when laying.

An example of this connecting method is shown in FIG. FIG. 2 is a vertical sectional view of the connecting portion.

(A) is an example in which a large number of snaps 10A, 10B are attached to the end of the water repellent air permeable sheet 2 and are fitted and connected at the connecting portion, and (b) is the end of the water repellent air permeable sheet 2. An example in which parts are partially overlapped and heat-fused and connected, and (c) is an example in which end portions of the water-repellent air-permeable sheet 2 are butted and bonded by an adhesive tape 11 to be connected.

[0019]

INDUSTRIAL APPLICABILITY The rainwater is prevented from infiltrating into the soil material at the time of rainfall, and the condensed water of the steam from the soil material is prevented from being reabsorbed by the soil material, and the surface quality of the soil structure is deteriorated by the rainfall. Is eliminated or reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view in which a soil structure is covered with a protective sheet used in the present invention during rainfall, (a) is a water-repellent breathable sheet, and (b) is a water-repellent breathable sheet. In the case of using the laminate of the breathable water-absorbing material, (c) is the case of using the laminate of the impermeable waterproof sheet and the water-absorbing material.

FIG. 2 is a vertical cross-sectional view of a protective sheet connecting portion, in which (a) uses snaps (b) uses heat fusion (c).
Is the case with adhesive tape.

[Explanation of symbols]

1 ・ ・ Soil structure, 2 ・ ・ Water repellent and breathable sheet, 3 ・ ・ Rainwater, 4 ・ ・ Surface water, 5 ・ ・ Steam, 6 ・ ・ Vented water absorbing material, 7 ・ ・ Condensed water, 8 ・ ・ No Breathable tarpaulin, 9 ...
Water absorbing material, 10A ・ ・ Snap (male type), 10B ・ ・ Snap (female type), 11 ・ ・ Adhesive tape.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Yaho 2-19-1 Tobita-Su, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Toshiyuki Tanaka 2-19-1 Tobita, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Center

Claims (3)

[Claims] 1. A method for protecting a soil structure during rainfall, which comprises covering the surface of the soil structure with a water-repellent breathable sheet during rainfall. 2. A method for protecting a soil structure during rainfall, which comprises covering the surface of the soil structure with a laminate of a water-repellent breathable sheet and a breathable water-absorbing material when it rains. 3. A method for protecting a soil structure during rainfall, which comprises covering the surface of the soil structure with a laminate of an impermeable waterproof sheet and a water-absorbing material when it rains.