JPH0372761B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a protective sheet for civil engineering that is laid and buried underground to prevent water, harmful substances, earth and sand from flowing into the surrounding area. Used for man-made rivers, various developed areas, industrial waste treatment plants, etc.

(Prior art and its problems) When constructing artificial rivers, gardens, golf courses and other developed areas, industrial waste disposal sites, etc., the ground surface of designated areas is excavated to the required depth and waterproof protective sheets are installed. Build and develop rivers, gardens, etc. on top of it to prevent water flowing down rivers or pooled in ponds from running away, and build and develop golf courses, etc. on top of it to direct rainwater to the place where drainage equipment is installed. Measures are being taken to prevent landslides by guiding them, and dumping industrial waste on top of them to prevent the outflow of hazardous substances.

Figure 8 is a cross-sectional view of one example, in which the ground surface is excavated to the required width and depth, and a flexible protective sheet 1 made of synthetic resin such as polyvinyl chloride is placed on top of the excavation to make it watertight. A garden is shown in which an artificial mountain 3 and a river 4 are created by laying the ground and mounding soil 2 for construction. In this case, if it is built in a wetland such as a swamp, the ground level will be 5.
Since the protective sheet 1 is soft and weak, there is a risk that the protective sheet 1 will sink unevenly even if the supporting piles are driven, and that it will be pulled too much and break. When a fracture occurs, it is virtually impossible to repair it because the location of the fracture is unknown because it is buried underground, and it is difficult to avoid accidents in which water, harmful substances, and construction soil flow out from the fracture site. Can not.

In addition, as shown in Japanese Patent Application Laid-Open No. 55-30023, a sheet with a loose part connected at both ends by a connecting means is used, and when a large tensile force is applied, the connecting means is destroyed. It has been thought that the sheet may be prevented from breaking by widening the slack part, but the slack part in this sheet is formed parallel to the shoulder of the slope, and the slack part is formed in a direction perpendicular to the shoulder of the slope. However, unexpected tensile forces often act in diagonal directions during embankment construction, waste disposal, or uneven settlement, and the direction of the force is In some cases, there is a concern that the connecting means may not be destroyed and the sheet may break.

(Means for Solving the Problems) The present invention provides a protective sheet for civil engineering that does not have to worry about breaking even if a tensile force is applied in any direction due to uneven subsidence of the ground or other causes. , is made of a flexible sheet material, and has loose parts extending diagonally to the longitudinal direction and arranged in cross directions with each other, and both edges of these loose parts are pulled together by a tensile force above a certain level. A means for solving the above-mentioned problems is achieved by configuring the devices to be connected by a connecting means that can be destroyed.

(Example) Embodiments of the present invention will be described based on the drawings.

Figure 1 shows a material with a thickness of 0.5 mm made of synthetic resin, asphalt-impregnated fabric, canvas, fiber-reinforced synthetic resin, etc.
A plurality of flexible and generally water-impermeable band-like sheet bodies 11, 11 of approximately 5 mm are overlapped with each other at their longitudinally extending edges, and these edges are watertightly connected by welding or gluing. A sheet material 13 is substantially formed by the lever connection portion 12, and each strip-shaped sheet body 11 has a plurality of loose portions 18 arranged in a direction inclined at 45 degrees with respect to the longitudinal direction thereof and perpendicular to each other. , 19 are formed at equal intervals, and the slack portions 18 and 19 of adjacent strip-shaped sheet bodies 11 extending in the same direction are aligned in a straight line without shifting in the longitudinal direction.

Further, in this embodiment, the slack portions 18 and 19 are formed at equal intervals, and are inclined at 45 degrees with respect to the longitudinal direction of each belt-shaped sheet body 11, and intersect with each other at right angles. It is possible to predict areas that are prone to uneven settlement based on the condition of the ground to be laid and the weight distribution of the construction soil piled on top of it, and to form those areas densely or to make loose areas large. , and each loosened part 1
The inclination angles 8 and 19 can also be set as appropriate depending on the installation location.

Figures 2 and below show an embodiment of a connecting means that forms a slack portion until it is broken by a tensile force above a certain level. In addition, in these examples, the loosened portion 18,
19 are collectively represented by the symbol 20.

The connecting means 21 in FIG. 2 includes a joint 24 made of the same material as the sheet material 13 and thinner than the sheet material 13 by welding or gluing across the edge parts 22, 22 on both sides of the loose part 20. They are fixed to the sheet material 13 and are provided at appropriate intervals.

The connecting means 21 in FIG. 3 is constructed by overlapping a sheet 25 made of the same material of the sheet material 13 and thinner than the sheet material 13 over the entire surface over the edge portions 22, 22 on both sides of the loose portion 20, and forming a joint similar to that described above. It is fixed to the sheet material 13 with 26.

The connecting means 21 in FIG.
At 22, the annular bodies 28, 28 are fixed to the sheet material 13 with the joints 29 similar to those described above, and string-like bodies 30 are wound around them, and are provided at appropriate intervals.

These connecting means 21 shown in FIGS. 2, 3, and 4 are connected to the joints 24, 26,
9 peels off or tape 23, sheet 25,
When the string-like body 30 breaks, it is destroyed and the slack portion 20 is expanded.

The connecting means 21 in FIG.
1, and when a tensile force above a certain level is applied, the welded portion 31 peels off and the loosened portion 20 expands.

The connecting means 21 in FIG.
Adhesive parts 33a and 33b formed with 2a at appropriate intervals
One of the adhesive parts 33a has a smaller area than the other adhesive part 33b, so the former adhesive part 33a peels off first.

The connecting means 21 shown in FIG. 7 fixes a tape 34 similar to that shown in FIG. Two folded portions 36a and 36b are formed inside the holder 20, and tapes 37a and 37b similar to those described above are fixed between their edges by the same means described above. These include first the joint 35 peeling off or the tape 34 breaking, then one tape 37a breaking or its joint peeling off, and finally the other tape 37b breaking or its joining. The parts peel off.

These connecting means 21 shown in FIGS. 6 and 7 expand the loose portion 20 in stages according to the tensile force, and the respective folded portions 32a, 32b, 36
By setting a and 36b to appropriate sizes, the interval between the slack portions 20 provided in the sheet material 13 can be increased.

(Effects of the Invention) When the protective sheet for civil engineering according to the present invention is laid down, for example, in the garden construction site shown in Figure 8, uneven settlement may occur locally due to the soft ground during or after embankment construction. Even if a large tensile force is applied, when a tensile force above a certain level is applied to the sheet material, the connecting means of the slack portion extending in the cross direction is destroyed faster than the sheet material breaks, and the sheet material expands by the amount of the slack portion. and follow uneven subsidence, etc.
The loose parts extend diagonally to the longitudinal direction of the sheet material and are formed in directions that intersect with each other, so that when a tensile force is applied to the sheet material in the longitudinal direction or the width direction, it is of course possible that the tensile force is applied in any direction. However, the sheet material can be expanded reliably without breaking. Therefore, it can be used by being laid underground without worrying about water, harmful substances, and soil flowing out or causing landslides in construction structures.

In addition, if the angle of inclination of the loose part with respect to the sheet body is 45 degrees with respect to the longitudinal direction of the sheet body, it can stably handle tensile forces in any direction, but the angle of inclination It is advisable to change it as appropriate depending on the slope and depth of the area.

[Brief explanation of drawings]

FIG. 1 is a front partial view showing an embodiment of the present invention; FIGS. 2, 3, 4, 5, 6, and 7 are perspective views of different embodiments of the connecting means; FIG. 8 is a schematic cross-sectional view showing an example of how the protective sheet is used. 13... Sheet material, 18, 19... Loose part, 2
1... Connection means.

Claims (1)

[Scope of Claims] 1. It is made of a flexible sheet material, and has slack portions extending diagonally to the longitudinal direction and arranged in directions crossing each other, and both end edges of these slack portions are formed. A protective sheet for civil engineering, characterized in that the sheet is connected by a connecting means that is destroyed by a tensile force exceeding a certain level. 2. The civil engineering protection sheet according to claim 1, wherein the loose portions are formed diagonally at 45 degrees with respect to the longitudinal direction of the sheet material and are orthogonal to each other.