JPH04336106A - Construction sheet for underwater work and method of laying the same - Google Patents

Abstract

PURPOSE:To carry out underwater laying of construction sheet easily and efficiently. CONSTITUTION:By heating and melting a construction sheet 2 applied with a hot-melt type adhesive 4 on its rear surface by means of an electric heater plate 30, the rough surface of revetment 8, such as of riprap or concrete, and the sheet 2 are securely bonded together. As the adhesive 4, the following are used; thermoplastic resin adhesives, EVA(ethylene-vinyl acetate copolymer), polyamide, crystalline 11-12, nylon, non-crystalline copolymerized nylon, and saturated amorphous polyester; rubber adhesives, SIS(styrene-isoprene-styrene block copolymer) and SBS(styrene-butadiene-styrene block copolymer).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a civil engineering sheet suitable for installation work underwater, and a method for laying this civil engineering sheet on the back of a seawall, the foundation of an underwater structure, etc.

0002

[Prior Art] Various civil engineering sheets, such as anti-sucking sheets and water-blocking sheets, are used in underwater civil engineering work. For example, when reclaiming the back of a seawall in offshore construction, it is necessary to remove soil and sand from seawater permeation. To prevent suction,
A water-permeable anti-suck sheet is being installed behind the seawall.

[0003] To explain this in the case of laying a sheet on the back of a rubble-type revetment, first, a single pipe or reinforcing rod is inserted between the rubble stones protruding above the water surface of the revetment, and this single pipe or reinforcing rod is The upper end of the sheet is fixed with iron wire or rope, and the diver dives while spreading the rolled sheet downward. At that time, they are temporarily fixed by placing stones at appropriate intervals on the sheet or by inserting reinforcing rods into the sheet. The work of rolling out and fixing the sheets is carried out one by one along the longitudinal direction of the revetment slope, wrapping approximately 50 to 100 cm between each sheet, and the diver joins them using grommets and ropes, and finally , soil from the back is thrown onto the sheet from the gut ship.

0004

[Problems to be Solved by the Invention] However, the method described above requires a huge number of man-hours for fixing the civil engineering sheets to the seawall using reinforcing rods and for connecting the civil engineering sheets with eyelets and ropes. Furthermore, the work of temporarily fixing the sheets with stones or sandbags when rolling them out is complicated.

The present invention aims to solve the above-mentioned problems, and its object is to provide a civil engineering sheet that is easy to install underwater, and a method for efficiently installing the sheet.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the civil engineering sheet for underwater work according to the present invention solves the problems by attaching a hot melt adhesive to the back surface of the sheet.

[0007] Further, the method for laying a civil engineering sheet according to the present invention is a method of laying a civil engineering sheet underwater by operating a hydraulic excavator equipped with a chuck at the tip of a sliding arm, and wherein the civil engineering sheet is laid underwater with the chuck. The problem was solved by means of supporting a heating means, using the heating means to heat and melt the adhesive of the civil engineering sheet to which a hot-melt adhesive is attached, and fixing the civil engineering sheet to the surface on which it is laid underwater. It is something.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a back view of the civil engineering sheet 2 of the present invention, and a hot melt adhesive 4 is provided in a frame shape near the edge of the back surface of the sheet 2. The reason why a hot-melt adhesive is used in the present invention is that the adhesive is solid at room temperature and water-insoluble, so that underwater construction can be carried out reliably. Note that solid insoluble adhesives include pressure-sensitive adhesives, but the latter generally have low adhesive strength and are therefore not suitable as adhesives for the present invention.

[0009] Hot-melt adhesives bond adherends together by heating and melting them, and there are many known types of adhesives, such as thermoplastic resin adhesives and rubber-based adhesives. . However, when considering the application of the present invention, that is, the adhesion between a construction surface such as rubble, concrete, etc. and a civil engineering sheet, there are only a few effective adhesives. According to the inventor's experiments, thermoplastic resin adhesives include EVA (ethylene-vinyl acetate copolymer), polyamide, crystalline
It has been found that 1-.12-nylon, amorphous copolymerized nylon, and saturated amorphous polyester are most suitable.

In addition, rubber adhesives include SIS (styrene-isoprene-styrene block copolymer) and S
BS (styrene-butadiene-styrene block copolymer) can be used.

[0011] The civil engineering sheet 2 is generally a water-permeable geotextile sheet for preventing suction and scouring, and when used for purposes such as preventing permeation of water or harmful substances, an impermeable geotextile sheet is used. A synthetic resin-based or rubber-based water-blocking sheet is used.

[0012] The state in which the adhesive 4 is attached to the sheet 2 does not necessarily have to be in a fixed state; it is sufficient that the adhesive 4 is completely adhered to the sheet 2 when it is adhered to the surface on which it is laid in water. Furthermore, if the same hot-melt adhesive as the adhesive 4 is applied to appropriate positions on the surface of the sheet 2, it becomes easy to wrap and bond the sheets together in the laying operation described later. As the adhesive for this purpose, the above-mentioned rubber adhesive is particularly preferable.

[0013] Next, the work of securing and securing the civil engineering sheet 2 to the seawall 8 will be explained. First, civil engineering sheet 2
This work is carried out by a diver or by mechanization using a hydraulic excavator as described below.

FIG. 3 is a perspective view showing how the civil engineering sheet is laid on the rubble type revetment 8.
The civil engineering sheet 2 is loaded in an expanded state on the barge 20 carrying the. The hydraulic excavator 10 has a sliding arm 12 so that it can be applied to deep water, and an attachment 14 is attached to the tip of the arm 12 so that the civil engineering sheet 2 can be directly operated.

Reference numeral 22 denotes an anchor wire, both ends of which are fastened to sea anchors 24, 24 to anchor the barge 20 on the sea. During the construction work, the barge 20 is moved back and forth and left and right by operating the winch 26 to wind up or loosen the anchor wire 22. Reference numeral 28 is a winch generator. barge 2
When the 0 position is to be significantly moved, the sea anchor 24 is replaced by the anchorage ship 6. Note that if a sufficient working space can be secured above the top of the seawall 8, the hydraulic excavator 10 can be installed directly on the seawall 8 to perform the work without using the barge 20.

The front surface of the attachment 14 is equipped with a hydraulic chuck 16 as shown in FIG.
After gripping the civil engineering sheet 2 with a hydraulic chuck 16, the hydraulic excavator 10 is rotated, the arm 12 is extended and contracted, and the entire civil engineering sheet 2 is pressed against the slope of the seawall 8. The pressing operation is performed by expanding and contracting the arm 12 and by winding up or loosening the anchor wire 22.

FIG. 2 shows a state in which the hydraulic chuck 16 grips the supporting portion 32 of the waterproofed electric heating plate 30, with reference numeral 34 indicating an electric wire, and reference numeral 36 indicating an electric wire attached to the sheet surface. It is a string made of heat-melting material. If one end of the string 36 is tied to an appropriate position on the electric heating plate 30 as shown in the figure, the pressing work of the civil engineering sheet 2 can be carried out on the electric heating plate 30.
This is convenient because the sheet fixing work described below can be performed almost simultaneously.

The work of fixing the civil engineering sheet 2 involves applying the adhesive 4 adhering to the back side of the sheet 2 to the sheet 2 using an electric heating plate 30.
This is done by heating and melting from the surface side. The heating temperature in water by the electric heating plate 30 varies depending on the type of adhesive 4, but is approximately in the range of 120°C to 300°C. The hot-melt adhesive 4 is heated and melted, and then, when the heating is stopped, it solidifies and firmly adheres the sheet 2 to a rough surface such as rubble or concrete of a seawall. At this time, the string 34 is melted and cut, and the sheet 2 is separated from the electric heating plate 30.

As the heating method, in addition to the above, it is also possible to employ thermite method or flame jet method, which are known as underwater welding method or underwater cutting method. Also,
The bond between each sheet 2 is 30 cm to 50 cm.
This is carried out with an overlap of cm. At this time, if the above-mentioned adhesive is attached to the surface of the sheet 2, the work will be easier.

In this way, while wrapping the sheets 2 to a predetermined width, the sheet 2 is wrapped one by one in the normal direction of the seawall 8.
Repeat the fixing work. Although the suction prevention sheet has been described above, the present invention can be applied to a water-blocking sheet in exactly the same manner.

[0021]

[Effects of the Invention] Although the civil engineering sheet according to the present invention has a simple structure in which hot-melt adhesive is attached to the back of the sheet, it exhibits the excellent effect of making installation work in water extremely easy. do. Therefore, the work of laying a suction prevention sheet or a water-shielding sheet in marine construction or the like can be carried out accurately and efficiently without being affected by waves.

Furthermore, since the method of laying a civil engineering sheet according to the present invention does not involve diving work, it is extremely safe in construction work such as the back of a seawall or the foundation of an underwater structure. Also,
The civil engineering sheet of the present invention also has the effect of establishing a new construction method for water-blocking sheets, since it can be easily constructed underwater.

[Brief explanation of drawings]

FIG. 1 is a back view of a civil engineering sheet according to the present invention.

FIG. 2 is a sectional view showing a state in which a civil engineering sheet is fixed to a laying surface by heating it using an electric heating plate.

FIG. 3 is a perspective view showing a state in which a civil engineering sheet is laid on the back side of a seawall by a hydraulic excavator.

[Explanation of symbols]

2 Civil engineering sheet 4 Adhesive 10 Hydraulic excavator 14 Attachment 16 Hydraulic chuck 30 Electric heating board

Claims (2)

[Claims] [Claim 1] A civil engineering sheet for underwater work, comprising a hot-melt adhesive adhered to the back surface of the sheet. 2. A method of laying a civil engineering sheet underwater by operating a hydraulic excavator equipped with a chuck at the tip of a sliding arm, wherein the chuck supports an underwater heating means, and the heating means is capable of: A method for laying a civil engineering sheet, which comprises fixing the civil engineering sheet to a submerged installation surface by heating and melting the adhesive of the civil engineering sheet to which a hot-melt adhesive is attached.