JP2001081758A - Protection sheet layer of civil engineering structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a gap between mutually connected parts and prevent soil and sand runoff by mutually overlapping and arranging the end edge part of a strip-like sheet material made of a synthetic fiber non-woven fabric having flexibility, elasticity, water-permeability and soil and sand impermeability, and joining them by welding. SOLUTION: The longitudinal end edge parts 2a, 3a of the long strip-like sheet material 2, 3 having proper thickness and width making a protection sheet layer 1 of a synthetic fiber are mutually overlapped at the proper width. Next, the overlapped end edge parts 2a, 3a are continuously heated and pressurized over the substantially entire length, and flexibility and deflection are secured and welded longitudinally and continuously. A number of the end edge part 2a, 3a of the similar sheet material 2, 3 are successively overlapped and arranged both sideward of the two sheet material 2, 3, and connected on a welding part 4 formed by the similar means without any gap. Thereby the runoff of soil and sand is completely prevented, a civil engineering structure is maintained over a long period by getting to fit to the shape of a set place, and the connection working of the sheet material 2, 3 can be easily performed at a jobsite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective sheet layer provided on the surface or inside of a civil engineering structure in order to measure the stability of the structure.

[0002]

2. Description of the Related Art Breakwaters and landfill revetments built on the sea floor,
In civil engineering structures such as artificial waterways and ponds built on the ground, and improved ground applied to soft land, to prevent settlement, collapse, and runoff due to sediment runoff, etc. It has been practiced to lay a protective sheet on the surface or inside.

That is, for example, as shown in FIG.
A base rubble 12 is laminated on the seabed 11 and a seawall main body 13 composed of a caisson is installed thereon, and the covering rubble 14 and the wave breaking block 15 are stacked on the sea area side of the seawall main body 13.
In a reclaimed revetment having a structure in which buried stones 16 are stacked on the buried side, a protective sheet layer 1 is provided on the surface of the seabed 11 on which the foundation rubble 12, the covering rubble 14, and the buried stone 16 are placed, and on the surface of the buried stone 16. Will be installed.

[0004] Protective sheet layer 1 installed on the surface of the seabed 11
The seawater flows through the gap between the basic rubble 12, the covering rubble 14, and the wave-dissipating block 15 due to the tide and waves on the sea area side, and the seabed 11
To prevent the earth and sand from spilling out, causing the entire reclaimed revetment to sink, slope and collapse. In addition, the protection sheet layer 1 installed on the surface of the backing stone 16 causes seawater to flow through the gap between the wave-dissipating block 15, the covering rubble 14, the foundation rubble 12, and the backing stone 16, and removes the landfill sediment. Prevents sinking and sinking.

[0005] For example, as shown in FIG.
The protective sheet layer 1 is installed on the back surface of the water-impervious sheet 23 in an artificial waterway having a structure in which a water-impervious sheet 23 is laid on the side and bottom of an open channel 22 formed by excavation on the ground surface portion 21.

[0006] The protective sheet layer 1 prevents the water impermeable sheet 23 from sliding on the excavated surface as a good fit, and when a sharp rock protrudes from the excavated surface, the rock penetrates the impermeable sheet 23. To prevent water leakage.

Further, for example, as shown in FIG.
In the improved ground having a structure in which the embankment layer 32 is covered on the soft ground 31 containing a large amount of water, the protection sheet layer 1 is provided between the soft ground 31 and the embankment layer 32.

The protective sheet layer 1 prevents the earth and sand forming the embankment layer 32 from sinking and flowing down into the soft ground 31 to form a mixed layer, thereby preventing the improvement effect from being lost or causing extreme uneven settlement.

As can be understood from the above examples of use, the protective sheet layer 1 has water permeability but does not allow earth and sand to pass, and is also excellent in flexibility, weather resistance, water resistance, tensile strength and elongation. Therefore, it is common to use a woven or non-woven fabric as the sheet material.

[0010]

The sheet material forming the above-mentioned protective sheet layer is formed in a long band shape having an appropriate width, stored and transported in a rolled state, unpacked at the installation site, and laid out. , Which are installed in the entire required installation range of civil engineering structures.

In this case, if the adjacent edge portions of a large number of sheet materials to be laid are left unconnected, earth and sand may flow out through the gaps, or the sheet materials may move individually. To prevent the stability of the civil engineering structure, it is necessary to connect the edge portions and make the protective sheet layer composed of a large number of sheet materials substantially a single sheet material.

As means for connecting the sheet material edge portions to each other, a connecting tool is attached to the edge of the sheet material, and the connecting tools are connected to each other while being unraveled and laid out.
Alternatively, it is considered to sew the edges while laying them out using a thread or metal wire, but in all cases, the connection work is troublesome and takes a long time, and there is no gap between them to prevent sediment loss. Is very difficult to do.

[0013] The present invention relates to a connection structure for protecting civil engineering structures, in particular, civil engineering structures that are in contact with water, having a protective sheet layer laid on the surface or inside thereof. To solve the above-mentioned problem that it is extremely difficult to eliminate the sediment runoff, and there is no gap between the sheet materials so that the sediment runoff can be completely prevented, and the connection can be made by extremely simple means. The purpose of the present invention is to provide a protective sheet layer in which portions are formed.

[0014]

Means for Solving the Problems In order to solve the above-mentioned problem of having a protective sheet layer laid on the surface or inside of the civil engineering structure to measure the stability thereof, the present invention is as follows.

That is, a large number of strip-shaped sheet materials made of a synthetic fiber non-woven fabric having water permeability, earth and sand impermeability, and flexibility and elasticity are arranged with their edges overlapping each other. Almost the entirety of the edge portions thus obtained was joined by heat welding.

As described above, since almost all of the edge portions are joined by heat welding, a connection portion without any gap is formed by extremely simple means, and the outflow of earth and sand is completely prevented, and the entire sheet material is integrally formed. It enhances the stability of civil engineering structures. Moreover, since it is made of synthetic fiber, it has excellent weather resistance, water resistance, and mechanical properties, and stably maintains the civil engineering structure for many months.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows FIGS.
FIG. 2C is a partial perspective view showing an example of a protective sheet layer in which an installation place is illustrated in (C), and the protective sheet layer 1 is a long strip-shaped sheet material 2 made of synthetic fiber and having an appropriate thickness and width. , superimposed with each other in the longitudinal direction edge portions 2 _a, 3 _a the appropriate width of 3, by the pressure continuously heating over the superimposed edge portions 2 _a, 2 _b on the almost entire surface, a longitudinal The two sheets 2 and 3 shown in FIG. 1 are heat-welded continuously in the direction without losing their flexibility and flexibility. A large number of portions are sequentially stacked and arranged, and they are connected to each other with no gap by a heat welding portion 4 formed by similar means. The heat seal portion 4 is very easily formed by synthetic fibers of edge portions 2 _a, 2 _b overlapping surfaces of welded together by hot melting.

Sheet materials 2 and 3 are transported in a rolled state, are unwound at an installation site and are sequentially joined, and those installed in a sea area as shown in FIG. 2A are heat welded on a work boat. And then pull it down into the sea or lay it in the sea and then heat weld.

The nonwoven fabric made of synthetic fibers constituting the sheet materials 2 and 3 is preferably made of polyester long fibers or short fibers or a mixture thereof, but in some cases, does not prevent natural fibers from being mixed. .

Polyester fibers have excellent heat resistance, oil resistance, and mechanical properties in addition to weather resistance and water resistance, and are suitable for components of civil engineering structures which are placed in a poor environment and are subjected to the weight and hydraulic pressure of the structures. is there. Also, non-woven fabrics made of long fibers generally have excellent tensile strength and tear strength, and non-woven fabrics made of short fibers generally have excellent elongation. By using it, it is possible to maintain a reliable civil engineering structure for a long period of time, and in some cases, mix long fibers and short fibers, or mix natural fibers to mix them. In some cases, it may have characteristics.

Further, the protective sheet layer in the present invention has water permeability in order to prevent the embankment layer from softening or flowing out due to rainwater, and is not only easily deformed due to the unevenness of the installation place, but also sharp. It is necessary to have flexibility, flexibility and toughness that cannot be pierced by broken rock. For this purpose, the sheet material is preferably a nonwoven fabric of an appropriate thickness made by shrinking or crimping.

Further, the nonwoven fabric forming the sheet material has a thickness of about 1 to 6 mm for long fibers and about 3 to 8 mm for short fibers, all of which have a weight per 1 mm thickness. Is preferably about 100 to 140 g / m ² , and an appropriate one is used depending on the application.

Further, it is necessary that the heat-welded portion has such a strength that it does not peel off by pulling.
It is preferable not to narrow the effective width of the sheet material,
For that purpose, it is preferable to form it with a width of about 35 to 50 cm.

[0024]

As described above, according to the present invention, it is possible to completely prevent outflow of earth and sand, to maintain the civil engineering structure for many months by adjusting to the shape of the installation site, and There is an advantage that sheet material connection work can be performed extremely easily.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing an embodiment of the present invention.

FIGS. 2A, 2B, and 2C are schematic diagrams illustrating examples of use of the present invention.

[Explanation of symbols]

1 protective sheet layer, 2,3 sheet material, 2 _a, 3 _a edge portion, 4 heat welded portion,

Claims (2)

[Claims] Claims: 1. A protective sheet layer provided on the surface or inside of a civil engineering structure to measure the stability of the civil engineering structure. The protective sheet layer is made of a synthetic fiber non-woven fabric having water permeability, earth and sand impermeability, and flexibility and elasticity. A protective sheet layer, wherein a large number of strip-shaped sheet materials are arranged such that their edge portions are overlapped with each other, and substantially all of the overlapped edge portions are joined by heat welding. 2. The protective sheet layer of a civil engineering structure according to claim 1, wherein the nonwoven fabric is made of polyester fiber.