JPH0619131B2 - Construction method of temporary revetment for landfill - Google Patents

Description

Detailed Description of the Invention A. OBJECT OF THE INVENTION (1) Field of Industrial Use The present invention relates to a temporary revetment used for landfills on coasts and the like, and in particular, it is constructed inside the revetment to perform reclamation concurrently with the construction structure of the revetment. It relates to a method of constructing a temporary revetment.

(2) Conventional technology Since the disposal of dredged soil to the public sea area during landfilling on the coast is regulated by landfill regulations, a main revetment should be constructed outside the landfill area and disposed inside it. Therefore, it is necessary to reclaim the land. However, since this revetment is a full-fledged structure using steel sheet piles, if the landfill work is started after the completion of this revetment, the entire construction period will be lengthened and it will be very uneconomical. is there. To this end, a temporary revetment is constructed by putting crushed stones into the sea by a gut ship inside the main revetment, and construction work of the main revetment and reclamation work inside the temporary revetment are carried out in parallel. The method of shortening is taken.

(3) Problems to be Solved by the Invention However, in the conventional method of constructing a temporary revetment, crushed stones or earth and sand are directly put into the sea, so that not only may nearby seawater be polluted and pollution may occur. However, there is a problem that the sediments that make up the temporary revetment are likely to flow out and cause the revetment to collapse.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a method for constructing a temporary revetment in which there is no risk of seawater contamination during construction and no outflow of sediment occurs even after construction.

B. Configuration of the invention (1) Means for solving the problems In order to achieve the above object, the method of the present invention is constructed closer to the land than the main revetment construction position in the landfill area, and after the main revetment is constructed, the landfill soil is constructed. A method of constructing a temporary revetment for landfills to be buried inside, in which a large number of blocks formed by covering the outer periphery of a frame body having a trapezoidal cross section with steel materials covered with canvas are submerged in water, and the ends of the blocks are Are connected to each other to define a predetermined temporary establishment area, and the block is filled with earth and sand or crushed stone from the upper bottom thereof.

(2) Operation The method of constructing a temporary revetment for landfill of the present invention having the above-described configuration is a block in which a frame having a trapezoidal cross section is preliminarily assembled on land using a steel material such as a shape steel, and the outer periphery thereof is covered with canvas. A large number of blocks are prepared and these blocks are sequentially sunk inside the main revetment using a crane ship. Next, connect the end faces of adjacent blocks to complete a continuous wall-shaped temporary revetment outer shell, and use a gut ship to put crushed stones, earth and sand etc. from the top bottom of each block to strengthen it. A temporary revetment. Then, the landfill is performed by discarding the dredged soil inside the temporary revetment. These works will be carried out in parallel with the construction of the main revetment, and after the completion of the main revetment, the landfill between the main revetment and the temporary revetment will be performed.

(3) Example An example of a method for constructing a temporary revetment for landfill according to the present invention will be described below with reference to the drawings.

In Fig. 2, the seabed is a supporting ground 1 made of hard soil,
It has a seabed 2 made of soft soil covering its surface, and a rubble mound 4 and a breakwater 5 are built on top of a replacement sand layer 3a which replaces a part of the seabed 2. A main revetment 6 located at the outer edge of the landfill is constructed offshore of this breakwater 5. The main revetment 6 is made by supporting a steel sheet pile 7 from behind with a slant retaining pile 8 and the upper end thereof is the highest tide surface H, W, L.
It is located at the landfill top L1 which is higher by a predetermined distance,
The lower end thereof penetrates the replacement sand layer 3b and reaches the support ground 1.

The temporary revetment 9 according to the present invention is located between the breakwater 5 and the main revetment 6 and is formed by connecting a large number of blocks 10 each having a trapezoidal cross section in a direction perpendicular to the plane of FIGS.
The upper end of the temporary revetment 9, which becomes the temporary landfill top L2, is slightly lower than the height obtained by subtracting the height H from the lowest tide surface L, W, L to the bottom of the maximum wave W (Fig. 1). A low pollution setting device 11 is provided at the upper end of the temporary revetment 9 to prevent pollution from flowing out from the upper part of the temporary revetment 9 to the main revetment 6 during temporary landfill.

FIG. 1 is a view showing a cross section of the temporary revetment 9. As is clear from this figure, the frame body 12 serving as a skeleton is made by welding light-weight steel into a shape having a trapezoidal cross section and having a predetermined length in a direction perpendicular to the paper surface. That is, the upper bottom member 12a, the lower bottom member 12b, and the hypotenuse member 12c form a trapezoid, and the inside thereof is reinforced by the reinforcing members 12d, 12e, 12.
Those reinforced by f, 12g, and 12h are connected by a large number of longitudinal members 12i. And the bottom member 1
The base angle α formed by 2b and the hypotenuse member 12c is set to be larger than the repose angle of the filling 13 put inside.

The outer periphery of the frame body 12, that is, the outer periphery of the upper bottom member 12a, the lower bottom member 12b, and the hypotenuse member 12c is reinforced with a canvas 14 to hold the filling 13. And the frame 1
The canvas 14 corresponding to the upper bottom portion 2 is not fixed to the upper bottom member 12a.
3 is thrown in. When the frame body 12 is large and the pressure of the filling 13 is large, the range of arrow A is reinforced with a wire mesh 15 as needed, and the outside of the canvas 1
4 is preferred.

In addition, since external pressure such as water pressure and earth pressure acts on the temporary revetment 9, stable calculation is performed, and if there is a possibility of slipping instability, the steel pipe should be positioned inside the frame 12. It is preferable to drive the anti-slip pile 16 to keep its stability.

As is apparent from FIG. 3, the outer periphery of the frame body 12 is covered with the canvas 14
The blocks 10 covered with 1 are sequentially connected in the sea by fastening the trapezoidal ends with bolts. The canvas 14 of each block 10 is bound by suturing the superposed with cord 18 in contact績部17 through Himoana 18 _1. Then, the filled filling 13 is prevented from flowing out.

The pollution preventive device 11 is provided at the upper end of the temporary revetment 9 configured as described above to prevent the pollution generated during temporary landfill from flowing over the upper end of the temporary revetment 9 to the main revetment 6 side. There is. This pollution control device 11 includes a membrane 20 made of canvas, one end of which is fixed to the upper end of the block 10 and the other end of which is fixed to a hollow pipe-shaped buoy 19.
Buoy 19 and block 1 to prevent tension from acting directly on
It is composed of a rope 21 stretched between the upper end of 0 and the upper end. The length of the rope 21 is set so that the buoy 19 does not sink below the sea level even when the sea level reaches the highest maximum tide level H, W, L.

Next, the operation of one embodiment of the method for constructing a temporary revetment for landfill according to the present invention having the above-mentioned configuration will be described.

Prior to the construction of the temporary seawall 9 in the sea, the block 10 is manufactured on the ground in advance. That is, the upper bottom member 12
a, lower bottom member 12b, hypotenuse member 12c, reinforcing member 12d
~ 12h, the longitudinal members 12i are welded to assemble the frame body 12, and then the outer periphery of the frame body 12 is covered with the canvas 14 to block the block 10.
To form. At this time, the canvas 14 that covers the upper bottom member 12a of the frame body 12 is left unfixed, and an opening for inserting the filling 13 in the sea is provided. If necessary, the lower half of the frame 12 may be reinforced with a wire mesh 15 before the canvas 14
The tension of the block 10 can increase the strength of the block 10.

The block 10 manufactured as described above is sequentially sunk by a crane ship so that the lower end of the block 10 is partially buried in the seabed 2 in the sea between the main seawall 6 and the breakwater 5, and a bolt or the like is used by the diver. After being connected using the fasteners, the overlapping portions of the canvas 14 of the adjacent blocks 10 are sewn with the string 18. Next, as shown in FIG. 4, the anchor rope 22
The lower end of the tremie pipe 25 suspended from the hopper 24 floated on the sea surface by the float 23 positioned at
0 Insert into the top opening. Then, by filling the stuffing 13 such as crushed stone or earth and sand into the hopper 24 with the grab bucket 27 of the gut ship 26, the filling 13 is introduced into the block 10 through the tremie pipe 25. Then, the filling 13 is compacted by the vibrator during the charging. At this time, the bottom angle α of the block 10 is 1
Since it is set larger than the angle of repose of 3, the filling 13
Will be filled in the block 10 without any gaps.

Then, the opening at the upper end of the block 10 is closed with a canvas 14, and the pollution prevention device 11 is attached. Since the buoy 19 of this pollution control device 11 can freely swing without countering the wave motion of the sea surface, it is possible to prevent the pollution caused by temporary landfill inside the temporary revetment 9 from flowing out to the main revetment 6 side. Moreover, the wave force acting on the film 20 connected to the buoy 19 does not directly propagate to the block 10.

The construction work of the above-mentioned temporary revetment 9 is carried out in parallel with the construction work of the main revetment 6, and after completion of the temporary revetment 9, temporary landfilling is carried out by discarding it inside. After the completion of the main revetment 6, the area between the main revetment 6 and the temporary revetment 9 is reclaimed, and further landfilling is performed on the upper part of the temporary landfill top L2 inside the temporary revetment 9. Thus, when the landfill up to the landfill top L1 located at the upper end of the main revetment 6 is finally completed, the temporary revetment 9 is buried in the landfill soil.

Although one embodiment of the method for constructing a temporary revetment for landfill according to the present invention has been described in detail above, the present invention is not limited to the above embodiment, and deviates from the invention described in the claims. It is possible to make various small design changes without any need.

For example, although the above embodiments relate to landfills on coasts, it is clear that the present invention can also be applied to landfills on lakes and rivers. In addition to crushed stone and earth and sand, building waste, waste stone, etc. can be used for filling the blocks.

C. EFFECTS OF THE INVENTION According to the method for constructing a temporary revetment for landfill of the present invention described above, a large number of blocks formed by covering the outer circumference of a frame body having a trapezoidal cross section assembled with steel material with canvas are submerged in water, and this block is submerged. The temporary reclaimed seawall is constructed by connecting the ends of each other to define a predetermined temporary landfill area and by filling the inside of the block with padding of earth and sand and crushed stone from the top and bottom of the block. Not only can pollution from the subsequent temporary landfill be effectively prevented from flowing out to the main revetment, but seawater pollution due to filling the inside of the temporary revetment can also be effectively prevented, which is effective in preventing pollution as a whole. Is. In addition, since the filling inside the temporary revetment is held in the frame body covered with canvas from the beginning of charging into the revetment, use a relatively small grain such as earth and sand as the filling material, and There is no risk of spillage or collapse, and the temporary revetment only needs to function for a short period of time until the completion of the main revetment.After the completion of the main revetment, it will be buried in the landfill soil. It is not necessary to maintain high strength for a long period of time, so it is possible to use not only a simple frame made of steel, but also earth and sand that easily collapse as a filling material, construction waste, etc. This makes the implementation easier and contributes to cost reduction.
Furthermore, since most of this temporary revetment can be manufactured and assembled on the ground beforehand, the construction period can be greatly shortened by burying it in the sea and starting the temporary landfill work at the same time when the construction of the main revetment begins. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a temporary revetment according to an embodiment of the method for constructing a temporary revetment for landfill according to the present invention, FIG. 2 is a schematic overall view of the same embodiment, and FIG. 3 is a temporary construction of the same embodiment. FIG. 4 is a perspective view of the seawall, and FIG. 4 is a view showing a filling method for filling the seams according to the embodiment. 10 ... Block, 12 ... Frame, 13 ... Filling, 1
4 ... Canvas, 16 ... Anti-slip pile, 23 ... Float, 25 ... Tremy tube

Claims (3)

[Claims] 1. A method of constructing a temporary revetment for landfill, which is constructed closer to the land than the main revetment (6) construction position in the landfill area and is buried in the landfill after the main revetment (6) is constructed. A large number of blocks (10) formed by covering the outer periphery of a frame body (12) having a trapezoidal cross section assembled with steel materials with a canvas (14) are immersed in water, and the ends of the blocks (10) are connected to each other. A method for constructing a temporary revetment for landfill is characterized in that a predetermined temporary landfill area is demarcated by the above and the inside of the block (10) is filled with padding (13) such as earth and sand or crushed stone from the upper bottom. 2. A pile (16) for preventing the block (10) from slipping.
The method for constructing a temporary revetment for landfill according to claim 1, characterized in that it is fixed to the ground by means of. 3. A hopper (2) having a float (23).
4) The temporary embankment for landfill according to claim 1, characterized in that the filling (13) is introduced into the block (10) through a tremie pipe (25) suspended from the lower part thereof. How to build.