JPH04118421A - Connection of sheet in water - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for connecting synthetic resin sheets forming a water-shielding wall when constructing a water-shielding wall such as an underground dam in the ground.

(Conventional technology) Conventionally, in order to construct an impermeable wall in soft ground, circular holes are drilled at regular intervals to reach the desired depth using a casing with a pit on the outer periphery of the tip, and then each circular hole is The wall material is filled with concrete or other wall material, and then, after the wall material has hardened, circular holes of the same diameter are drilled between adjacent circular holes, and the same wall material is filled into the circular holes and allowed to harden. By repeating this process, a continuous impermeable wall is constructed.

In this case, the lap width between the circular holes becomes the effective wall thickness of the impermeable wall, but if the vertical excavation accuracy of the circular hole becomes inconsistent, the lap width decreases as the depth of the circular hole increases. Therefore, it is necessary to reduce the excavation pitch between the circular holes so that it is equal to or greater than the effective lap width, which not only requires a large amount of wall material but also reduces construction efficiency. I will do it.

For this purpose, circular holes are drilled at regular intervals, narrow grooves are drilled between adjacent circular holes, and both ends of the narrow grooves communicate with the circular holes, while a water-blocking sheet with guide members fixed to both ends is used. Then, the water spray sheets are sequentially inserted into the narrow grooves while inserting the guide members into the adjacent circular holes, and the guide member on the other end of the next water spray sheet is engaged with the guide member on the one end side of this water shield sheet. The present application provides a method of constructing a series of impermeable walls by inserting the water-shedding sheet into the adjacent narrow groove in the same manner, repeating this operation, and filling the circular hole and the narrow groove with cement, etc. Developed by Applicant et al.

(Problem to be Solved by the Invention) However, according to the above method, not only is it necessary to attach guide members to both ends of a water sheet in advance, but also it is necessary to install guide members at both ends of a large number of water sheets in a watertight manner with precision. It is difficult to bond and image the water, there is a risk of water leakage when a water-shielding wall is constructed due to poor bonding in some areas, and guide members are attached to both ends of the water-shedding sheet. Moreover, handling during transportation and construction becomes complicated, leading to a decrease in work efficiency.

In addition, because the length of the water-shedding sheet and guide members are set in advance according to the depth of the impermeable wall to be constructed, it is difficult to respond when the depth of the impermeable wall changes. Moreover, when constructing a water-shielding wall, the guide members of the opposing water-shedding sheets are simply engaged with each other as described above, so the water-stopping properties at this engaging part are poor, and the water-shielding wall There have been problems such as cases in which the device may not be able to perform its full function.

The present invention aims to solve these problems, and it is an object of the present invention to provide a sheet that can be easily joined and bonded at both ends of the sheet underwater without attaching guide members or the like to both ends of the sheet. It provides a connection method.

(Means for Solving the Problems) In order to achieve the above object, the underwater sheet connection method of the present invention is such that guide piles are erected in water at regular intervals, and synthetic resin sheets are sequentially inserted between the guide piles. A method of polymerizing the opposite ends of stretched and adjacent synthetic resin sheets on the surface of a guide pile and connecting the polymerized parts, in which an ultrasonic welding device is lowered along the length of the guide pile. At the same time, the ultrasonic welder of the ultrasonic welding device that is brought into sliding contact with the overlapping portion of the synthetic resin sheet is covered with compressed air supplied from the ground, and the overlapping portion of the synthetic resin sheet is bonded by the ultrasonic welder. It is characterized by ultrasonic welding.

(Function) A narrow trench of a specified depth is excavated in the area of the ground where an impermeable wall is planned to be constructed.
When constructing a continuous impermeable wall using a water sheet in the narrow trench in the presence of water such as muddy water used during the excavation, first, a length with a constant width corresponding to the spacing between the guide piles to be built in the water is required. After winding up a synthetic resin sheet of approximately 300 mm in length and placing guide piles at predetermined intervals within the narrow grooves, the synthetic resin sheet is stretched between the guide piles and laid out to a desired depth. Set up

When the second sheet tensioning operation is performed between the next guide piles, the opposing ends of the synthetic resin sheets on both sides overlap on the guide piles in the center.

In this state, the ultrasonic welding device is lowered along the guide pile over the opposing ends of the synthetic resin sheet polymerized on the surface of the guide pile, and the ultrasonic welding device is applied to the overlapped portion of the sheets while applying ultrasonic waves. When oscillated, the bonding surfaces of the overlapping portions of the sheets are welded together and formed into an image. At this time, direct ultrasonic welding in water consumes a large amount of energy in the welder, and it is difficult to weld the sheets due to the cooling effect of the water. Since ultrasonic waves are generated while removing water using compressed air supplied from the ground, welding and joining can be performed reliably.

In this way, once the synthetic resin sheets have been connected to each other at the predetermined location, the ultrasonic welding device is pulled up and the guide pile is moved to the next position, and the next sheet connection operation is performed.This operation is repeated to complete a series of After forming the water barrier sheet, a filler material such as concrete is injected into the narrow groove to construct a water barrier wall with the water barrier sheet embedded.

(Example) An example of the present invention will be explained based on drawings in a method of constructing an impermeable wall of an underground dam, etc. First, as shown in Figs. A narrow trench (with a depth reaching from the ground surface to the impermeable layer (2)
3) Excavate.

The narrow groove (3) is excavated by a known method, for example, by using a casing with a pit on the outer periphery of the tip, a circular hole reaching a desired depth is excavated at an appropriate location in the ground (1), and then a circular hole is excavated to a desired depth. A method in which a guide member is installed in the hole and a narrow groove portion corresponding to the width and length of the excavator is repeatedly excavated in the ground using an appropriate excavator along this guide member, or a circular groove as described above is used. After holes are drilled at regular intervals, a frame body with an endless cutter such as a wire saw or a chain saw on the outer periphery is placed between these circular holes so that it can be raised and lowered, and the endless cutter is driven to travel. This can be done by, for example, drilling narrow grooves in the ground between the circular holes.

Note that the narrow groove (3) is filled with water due to muddy water such as bentonite that is injected during excavation.

In this way, after excavating the narrow groove (3) or following the excavation of the narrow groove (3) of an appropriate length, guide piles made of metal such as iron ( 4) Erection (4) and drive its lower end into the impermeable layer (2).

As shown in Fig. 3, the shape of this guide pile (4) includes engagement protrusions (4
a) It has a convex cross section formed by protruding (4a).

Next, a synthetic resin sheet (5) that is impermeable to water and capable of ultrasonic bonding, such as a vinyl chloride sheet, having a width larger than the width between these guide piles (4) (4) is attached to both ends thereof. is inserted into the narrow groove (3) between the two guide piles (4) (4) so as to follow the surface of the guide piles (4) (4).

As shown in Fig. 4, the synthetic resin sheet (5) is a long sheet with a constant width that is wound into a roll, and is arranged so that it can be fed out above the narrow groove (3). At the same time, a guide member (6
), as shown in Figure 5, L-shaped guide pieces (6a) protruding from both ends of this guide member (6).
(6a) of the guide pile (4) (4)
4a) While engaging with (4a), feed it out to form the narrow groove (
3) is stretched to the bottom.

In addition, one end of the synthetic resin sheet (5) that is first inserted and arranged in the narrow groove (3) is integrally embedded and fixed to the wall surface of the narrow groove (3) by appropriate means, and other The end portion is along the surface of the one guide pile (4), and the one end portion of the synthetic resin sheet (5) to be inserted next is aligned with the surface of the synthetic resin sheet (5) that has already been stretched. overlapped on the other end.

In this way, the opposing ends of the adjacent synthetic resin sheets (5) (5) on the surface of one guide pile (4) are polymerized (5).
a) After the above state is achieved, the superposed portion is welded using an ultrasonic welding device (7).

As shown in Fig. 6, this ultrasonic welding device (7) has an opening facing the guide pile (4) in a cart (8) having moving wheels (9) with magnets equipped with permanent magnets on the surface. A deep dish-shaped cover unit 0ω is integrally attached, and an ultrasonic welder (7a) and a pressure air injection nozzle θD are arranged inside the cover unit 00). A moving rope Q21 is connected to the end of the ultrasonic welder (7a), and the base end of the ultrasonic welder (7a) is pivotally connected to the cover (Oa) so as to be rotatable back and forth. 0
Place a spring 0 between 0 and use an ultrasonic welder (7a)
The oscillation port of the guide pile (4) is always brought into elastic contact with the guide pile (4). In addition, the open end of the compressed air injection nozzle OD faces close to the oscillation port of the ultrasonic welder (7a), and the base end is connected to the compressed air installed on the ground via a pullable air supply hose 04). It is connected to a supply source (not shown).

This ultrasonic welding device (7) is suspended between the polymerized synthetic resin sheet (5) (5) on the guide pile (4) and the opposing inner wall of the narrow groove (3) via a moving rope 021, and its wheels (9) is magnetically attached to the guide pile (4) via the synthetic resin sheet (5) (5), and the ultrasonic welder (7a)
is applied onto the overlapping portion (5a) of the synthetic resin sheet (5) (5) with a spring force of 0.

In this state, the ultrasonic welding device (7) is moved along the guide pile (4) while suspending the moving lobe surface, and the synthetic resin sheet is
5) Weld the overlapping part (5a) of (5).

At this time, when compressed air is supplied from the ground to the injection nozzle O1 through the air supply hose Q41, the compressed air is
The water inside the cover assembly 0[1] is discharged outside, and the inside of the cover assembly aω is filled with compressed air, and the ejected pressure causes the tip oscillation port of the ultrasonic welder (7a) to emit air. (in addition to the synthetic resin sheath)
(5) The overlapping part (5a) of (5) is attached to the ultrasonic welding device (7)
The guide pile (4) is moved by the magnetic force of the moving wheels (6).
The overlapping portions (5a) are brought into pressure contact with each other, and the overlapping portions (5a) are reliably and firmly welded and imaged.

In addition, as a means for moving the ultrasonic welding device (7) while magnetically attaching it along the guide pile (4), instead of using the moving wheels with magnets (9) as described above, as shown in FIG. , a caterpillar (9a) having a large number of magnet pieces attached to its surface may be used.

In this way, the ultrasonic welding device (7) is attached to the guide pile (4).
The jet nozzle is lowered into the water in the narrow groove (1) along the
Ultrasonic welder (7a) by compressed air jetted from 0
After joining the polymerized portions (5a) of the synthetic resin sheets (5) (5) over the entire length while excluding surrounding water, the ultrasonic welding device (7) is pulled up, and then the polymerized portions (5a) are bonded on the surface.
After pulling up the guide pile (4) to which 5a) is welded, it is again placed in the narrow groove (3) at a certain distance from the other guide pile (4), and then the lower end is removed in the same manner as above. A synthetic resin sheet (5) equipped with a guide member (6) is inserted between these guide piles (4) (4).

In addition, since the synthetic resin sheet (5) with one end welded is continuous from the wound sheet on the ground side, it is cut at a suitable place and a guide member (6) is attached to the cut end. It is prepared for the next installation, but when it is cut,
Since the other end of the sheet that has not yet been welded will tremble as it comes loose from the guide pile that will be welded next, connect the upper end of the other end to the second guide pile (4) using an appropriate connection fitting or connection. It is temporarily fixed using a kimono, but in addition to the tensioning means, for example, two rolled sheets,
If the sheet rolls connected to the synthetic resin sheet (5), which are arranged in parallel on the narrow grooves (3) and whose both ends are welded, are moved to the next insertion and tensioning point, the rolled sheet portion Both ends of the synthetic resin sheath (5) (5) pulled out from the guide pile (4) can always be held in close contact with each other on the guide pile (4) (4).

In this way, the guide pile (
4) Inserting and stretching the synthetic resin sheet (5) above the space between (4) and moving the overlapping portions of the opposing ends of the adjacent synthetic resin sheets (5) and (5) on the guide pile (4) , Welding and imaging by the descending ultrasonic welding device (7), and relocation of the guide pile (4) to the next sheet connection position are repeated in sequence, so that the entire length within the narrow groove (3) is After installing a continuous synthetic resin sheet, guide piles (
4) Remove (4) to the ground and then pour in cement to harden the bentonite liquid (05), or fill the narrow groove (3) with an appropriate filler such as concrete and fill it inside. This involves constructing a water-blocking wall with a continuous synthetic resin sheet embedded in it.

In the above embodiments, a thin groove (3) is excavated in the ground and the synthetic resin sheet 1- (5) (5) is placed in the water.
), the present invention is applicable not only to such narrow slots but also to any location as a method of connecting synthetic resin sheets (5) (5) underwater. .

(Effects of the Invention) As described above, according to the method for connecting sheets underwater according to the present invention, first, kite piles are erected in water at a certain interval, and synthetic resin having a certain width is placed between these guide piles. Since the sheet is arranged along the length of the guide pile, a long synthetic resin sheet is wound in advance and the wound sheet is rolled out to the desired length to be stretched between the guide piles. This not only makes it easy to transport and handle the synthetic resin sheet during construction, but also allows for accurate tensioning in the direction of unwinding, making it possible to efficiently and efficiently tension the sheet between the guide piles. It can be done accurately.

Further, the opposite ends of the synthetic resin sheet stretched first and the synthetic resin sheet stretched next are overlapped on the guide pile, and the opposite ends of the synthetic resin sheet polymerized on the surface of the guide pile The overlapping part is welded while the ultrasonic welding device is lowered along the guide pile, making it possible to weld even in narrow spaces such as narrow slots, and ultrasonic welding is possible. Since ultrasonic waves are generated while water in the visceral bones is removed by compressed air supplied from the ground, the energy loss of the ultrasonic welding device is reduced and reliable welding and joining can be performed.

At this time, if the ultrasonic welding device is magnetically attached to the guide pile and lowered along the guide pile, the ultrasonic welding device can be lowered accurately and the synthetic resin sheet can be bonded by the ultrasonic welding device. The overlapping portion is pressed onto the guide pile and can be welded with high precision.

Further, after the overlapping ends of the synthetic resin sheets are connected together by the above-mentioned welding means, the guide pile at that part is moved to the next welding work position, so that it can be reused for connecting synthetic resin sheets having a certain width. Even a long water spray sheet made of a series of synthetic resin sheets can be efficiently constructed using several guide piles.
Moreover, after construction, the guide pile can be removed and a water-spraying sheet made only of the connected synthetic resin sheet can be obtained.
This makes it possible to create a water-blocking wall that exhibits complete water-stopping properties, including the welded joints.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a partial plan view of a narrow groove excavated in the ground, Fig. 2 is a simplified vertical side view thereof, and Fig. 3 is a guide pile and a guide pile in the narrow groove. Fig. 4 is a simplified side view of the state in which the synthetic resin sheet is inserted and arranged along the guide pile, Fig. 5 is its plan view, and Fig. 6 is a plan view of the state in which the synthetic resin sheet is inserted and arranged. Fig. 7 is a simplified side view of an ultrasonic welding device for welding the overlapping parts of synthetic resin sheets; Fig. 7 is a simplified side view of an ultrasonic welding device with a different structure; Fig. 8 is a front view of the water spray sheet after construction; Fig. 9 The figure is a simplified plan view of the constructed impermeable wall. (1)...Ground, (2)...Impermeable layer, (3)...
・Narrow groove, (4)...Guide pile, (5)...Synthetic resin sheet, (5a)...Overlapping part, (6)...Guide member, (7)...Ultrasonic welding Equipment, (IQ... pressure air injection nozzle, ari... moving rope.

Claims (1)

[Claims] (1) Guide piles are built into the water at regular intervals, and synthetic resin sheets are sequentially stretched between the guide piles, and the opposing ends of adjacent synthetic resin sheets are polymerized on the guide pile surface. A method for connecting overlapping parts, wherein the ultrasonic welding device is lowered along the length of the guide pile, and the ultrasonic welding device of the ultrasonic welding device is brought into sliding contact with the overlapping portion of the synthetic resin sheet above the ground. 1. An underwater sheet joining method characterized by ultrasonically welding a polymerized portion of a synthetic resin sheet using the ultrasonic welder while the sheet is covered with compressed air supplied from a synthetic resin sheet.