JP4320972B2 - Landfill soil runoff prevention structure for quay and revetment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a structure for preventing discharge of landfill on a quay or revetment.
[0002]
[Prior art]
There is a risk of the landfill soil flowing out to the sea side through a gap in the caisson joint or the like due to the flow of seawater due to waves or the seepage flow caused by the residual water level on the landfill soil side. If landfill soil flows out, it will cause local depression of the ground behind the seawall, etc., and in some cases disasters due to land subsidence will also occur.
[0003]
Therefore, it is necessary to take sufficient measures to prevent outflow of landfill at the quay and revetment. In gravity-type revetments and quays, the caisson joints used in the revetments and quays (the joint between the caisson and the caisson) are weak points against the outflow of landfills. It is described in an experiment on subsidence disaster behind the revetment (Ocean Development Paper Vol.10 June 1994).
[0004]
Up to now, as a countermeasure for preventing the outflow of landfill soil, as shown in the plan view of FIG. 4, a bag joint 43 is formed on the joint 41 of the case 41 and the joint 41 from the upper end to the lower end of the case 41. The bag joint 43 prevents the landfill 44 on the land side 44 from flowing out to the sea side 45, or the case 51 and the joint 52 of the case 51, as shown in the plan view of FIG. 5. On the land side 53 of the portion, a joint plate 54 is arranged from the upper end to the lower end of the case 51, and the joint plate 54 prevents the landfill 53 on the land side 53 from flowing out to the sea side 55. It was.
[0005]
In addition, according to “Technical Standards and Explanations for Port Facilities” (supervised by the Port Authority of the Ministry of Transport) Are listed. That is, the following three effects can be expected when backfilling is performed.
(A) Reduction of earth pressure due to increase in internal friction angle (b) Reduction of residual water level due to increase of water permeability (c) Reduction of earth pressure and reduction of residual water level in backfill prevention work These two points are not necessary if the design can sufficiently cope, and it is only necessary to prevent the outflow of the backfill earth and sand.
[0006]
FIG. 6 is a cross-sectional view showing such a backfilling work, in which a backstone 63 is stacked in a triangular shape with a gradient of about 1: 1.2 adjacent to the land side 62 of the case 61. A sheet (sand-prevention sheet) 64 for preventing discharge of landfill is laid on the piled backstone 63, and landfill 65 is reclaimed from the sheet.
[0007]
[Problems to be solved by the invention]
However, the backfilling work that can be expected to prevent the landfill outflow described above has the following problems. Since lining stones are piled up over the entire length of the quay and revetment, severe diving work is required for that purpose, and work for leveling the lining stones and laying sandproof sheets are complicated. It is too expensive to use as a preventive measure against landfill runoff at quay and revetment.
[0008]
The present invention was made to solve the above-mentioned problems of the prior art, and since the backfilling work can be easily performed, a quay / The purpose of this project is to provide a preventive structure for the revetment of the revetment.
[0009]
[Means for Solving the Problems]
The landfill discharge prevention structure of the first quay / revetment used as a reference of the present invention is located adjacent to the land side of the quay / revetment so that it has a downward slope toward the land side from the quay / revetment. After piled up stones, a sand-proof sheet was laid on the back lining stone, and the landfill on the land side of the quay and revetment, After installing the back lining stone input frame that covers the joint part, and then inserting the lining stone into the lining stone input frame, cover the lining stone together with the lining stone input frame with a sand-proof sheet, Incorporating clay.
[0010]
In the first quay and revetment landfill outflow prevention structure according to the present invention, the backside stone covering from the lower end to the upper end of the joint portion on the land side joint portion of the quay and revetment which is the weakest place for the landfill outflow After setting up the input frame and inserting the back lining stone into the back lining stone input frame, cover the back lining stone with the sand proofing sheet together with the lining stone input frame, and input the back lining soil from above. Yes.
[0011]
Therefore, the amount of back lining stone used is small, the cost and amount of work required for the back lining work can be reduced, and the effect of preventing the outflow of landfill can be sufficiently exhibited.
[0012]
The landfill discharge prevention structure of the second quay / revetment according to the present invention is adjacent to the land side of the quay / revetment using an L-shaped block, and has a downward slope toward the land side from the quay / revetment. In the structure for preventing outflow of landfill from the quay and revetment in which a sand proof sheet is laid on the backfill and landfill is reclaimed on it, the length of the L-shaped block is On the land side that is a certain distance away from both ends in the direction, a lining stone input wall for covering the joint portion of the L-type block with a lining stone is provided, and is formed between the lining stone input walls of adjacent L-type blocks. After inserting the back lining stone into the back lining stone input section, the back lining stone is covered with a sandproof sheet together with the lining stone input section, and the back lining soil is input from above.
[0013]
This landfill discharge prevention structure on the quay / revetment requires the same amount of cost and work as the first quay / revetment landfill outflow prevention structure, and can also fully demonstrate the effect of prevention of landfill discharge.
[0014]
In addition, when using an L-shaped block, by installing a back stone input wall for introducing a back stone in advance at a position away from the both ends in the longitudinal direction of the L-shaped block, The space between the lining stone input walls of adjacent L-shaped blocks can be used as the lining stone input portion, and no special frame is required.
[0015]
The third quay and revetment landfill outflow prevention structure used as a reference for this invention is a pair of lining stone input frames with a length higher than the sea level across the land side joint of the quay and revetment. After installing the mounting bracket vertically, mounting a backstone input frame with a U-shaped cross section and a height higher than the sea level to the mounting tool, and after inserting the backstone into the backstone input frame , The back soil is thrown in from above.
[0016]
This structure to prevent the reclamation of the landfill on the quay / revetment is a pair of lengths that are higher than the sea level, with a U-shaped back-filled stone insertion frame sandwiched between the landside joints of the quay / revetment. Since it only needs to be attached to the fitting for attaching the back stone input frame, construction can be performed easily.
[0017]
Also, since the height of the back lining stone input frame is higher than the sea level, the height of the lining stone at the joint is also higher than the sea level, and the lining stone is covered with a sand-proof sheet. Even without it, the backfill does not flow out of the joints.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view of a first embodiment used as a reference for a structure for preventing discharge of landfill on a quay and revetment according to the present invention. FIG. 1 (a) is an illustration of a backstone input frame installed in a joint part of a caisson. A perspective view, (b) is a plan view showing a connection portion between a caisson, a back lining stone input frame and a sand-proof sheet, and (c) is a back lining stone inserted into the back lining stone input frame and other portions. It is a top view which shows the state which injected | thrown-in soil.
[0019]
In this landfill prevention structure for berths and revetments, a lining stone input frame 4 for inserting the lining stone 8 is arranged at the joint 2 on the land side 3 between adjacent cases 1. . The shape of the side wall 4a of the lining stone input frame 4 is a right triangle, and the two side walls are connected by a plurality of connecting members 4b. And the inclined surface which goes down toward the land side 3 is formed by the inserted back lining stone 8.
[0020]
As shown in FIG. 1 (b), the back-filling stone insertion frame 4 manufactured in advance in the factory inserts the engaging portion 4 c into the slit portion of the insertion fitting 5 attached to the case 1. Thus, it is fixed to the case 1. Further, one end of a sandproof sheet 6 is fixed in the vertical direction on the side wall 4a of the back stone input frame 4, and a sandproof sheet fixing jig 7 is fixed to the other end of the sandproof sheet 6. Is attached. And the sandproof sheet fixing jig 7 is also inserted into the other slit portion of the insertion fitting 5 so that the back soil does not flow out between the case 1 and the back stone input frame 4. Yes.
[0021]
FIG. 1 (c) shows a state in which the back lining stone 9 is thrown around the back lining stone throwing frame 4 after the lining stone 8 is thrown into the lining stone throwing frame 4 arranged as described above. Yes. The sand-proof sheet 6 is pressed against the back-filling stone loading frame 4 by the inserted back-filling soil 9 so that the back-filling soil 9 cannot flow out between the case 1 and the back-filling stone loading frame 4. ing.
[0022]
Although not shown in FIG. 1 (c), the backside soil 9 is also introduced above the portion where the backstone 8 is finally stacked. A sand-proof sheet is laid on the top to prevent outflow of back soil from the slope.
[0023]
By adopting such a structure, it is possible to prevent installation errors in the direction perpendicular to the normal of the caisson (the longitudinal direction of the caisson) and torsion caused by uneven settlement due to consolidation after the caisson is installed. Since the structure is rich in flexibility, it can be sufficiently dealt with.
[0024]
In addition, in Fig.1 (a), the code | symbol 10a is the seabed ground, and the code | symbol 10b is a basic rubble mound.
[0025]
Next, a second embodiment of the structure for preventing discharge of landfill on a quay / revetment according to the present invention will be described with reference to FIG. FIG. 2 is an explanatory view of the second embodiment of the structure for preventing discharge of landfill on the quay and revetment according to the present invention. FIG. 2 (a) is an L-shaped caisson provided with lining stone input walls at both longitudinal ends. (B) is a perspective view showing a back pebbles input frame formed between the lining stone input walls of two adjacent L-shaped caissons, (c) is a back view of the back pedestal input frame. It is a perspective view which shows the state which put in a stone.
[0026]
In this berth / revetment landfill outflow prevention structure, the front wall 11 is located on the sea side 12 and the bottom slab 13 is located on the land side 14 to prevent the front wall 11 from collapsing along the longitudinal direction. The L-shaped caisson 16 is provided with a plurality of stiffeners 15 and the L-shaped caisson has a side sandwiching a right angle so as to be positioned at a distance T from the both ends in the longitudinal direction. 16 is provided with a substantially triangular lining stone input wall 17 in contact with the front wall 11 and the bottom slab 13, and the end wall for forming the joint portion 18 of the adjacent L-shaped caisson 16 at both ends. 19 is provided.
[0027]
FIG. 2 (b) shows two L-shaped caissons manufactured as described above arranged in the longitudinal direction so that the plate surfaces of the end wall 19 provided at the end are in contact with each other. However, one backside stone input wall 17 is located on each of the left and right sides of the two wall walls 19 that are in contact with the plate surface. In between, a back stone input part 20 is formed.
[0028]
FIG. 2 (c) shows that the back slab 21 is put into the back slab insert 20 formed by the two back slab inserts 17 around the joint 18 of the L-shaped caisson 16 described above. Shows the state. In the case of this embodiment, the L-shaped caisson 16 and the back-filling stone input wall 17 can be formed integrally, so that it is not necessary to arrange a sandproof sheet at the contact portion between them. Further, as in the case of the first embodiment, there is no need to attach a backstone input frame.
[0029]
Therefore, after inserting the back lining stone 21 into the back lining stone input section 20, a sandproof sheet (not shown) is laid on the back lining stone 21 and then the back lining soil is input. Good.
[0030]
Next, a third embodiment as a reference for the landfill outflow prevention structure of the quay and revetment of the present invention will be described with reference to FIG. FIG. 3 is an explanatory view of a third embodiment used as a reference for the landfill outflow prevention structure of the quay and revetment of the present invention. FIG. A perspective view and (b) are top views which show the connection part of a case and a back lining stone insertion frame.
[0031]
In this berth / revetment landfill outflow prevention structure, a lining stone input frame 34 for inserting the lining stone 36 is arranged at the joint 32 portion of the land side 33 between adjacent cases 31. . The shape of the lining stone input frame 34 has a U-shaped horizontal cross section, and by inserting the engaging portion 34 c into the slit portion of the mounting bracket 35 attached to the case 31, Fixed to case 1.
[0032]
Then, after attaching the back lining stone input frame 34, the back lining stone 36 is input into the back lining stone input frame 34, and the back lining soil is input from above. Since the height of the lining stone input frame 34 is higher than the sea level outside the case 31, the height of the lining stone can be made higher than the sea level, and it is put on the lining stone. Since the backfill soil does not contact seawater, the backfill soil will not be sucked into the seawater even if a sand-proof sheet is not placed on the backfill stone.
[0033]
【The invention's effect】
According to the present invention, it is possible to prevent outflow of landfill on the quay and revetment at a low cost.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram of a first embodiment used as a reference for a landfill outflow prevention structure for a quay and revetment according to the present invention, and (a) is a backstone input frame installed in a joint part of a caisson. (B) is a plan view showing a connection portion between a caisson, a back stone input frame and a sand-proof sheet, and (c) is a back surface stone placed on the back stone input frame and the other part. It is a top view which shows the state which injected the earth.
FIG. 2 is an explanatory view of a second embodiment of a structure for preventing discharge of landfill on a quay wall / revetment according to the present invention, wherein FIG. 2 (a) is an L-shaped cage provided with lining stone input walls at both longitudinal ends. (B) is a perspective view showing a back stone input frame formed between the back wall input walls of two adjacent L-shaped caissons, (c) is a back stone input frame. It is a perspective view which shows the state which injected the backfill stone.
FIG. 3 is an explanatory view of a third embodiment used as a reference for the landfill outflow prevention structure of a quay and revetment according to the present invention, and (a) is a backstone input frame installed in a joint part of a caisson. (B) is a top view which shows the connection part of a case and a back stab stone input frame.
FIG. 4 is a plan view showing a landfill outflow prevention method from a joint portion of a caisson using a conventional bag joint.
FIG. 5 is a plan view showing a landfill outflow prevention method from a joint portion of a caisson using a conventional joint plate.
FIG. 6 is a cross-sectional view showing a conventional backfilling work with a landfill outflow prevention effect.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 2 Joint 3 Land side 4 Backing stone insertion frame 5 Insert metal fitting 6 Sand protection sheet 7 Sand protection sheet fixing jig 8 Back stone 9 Backing soil 11 Front wall 12 Sea side 13 Bottom plate 14 Land side 15 Stiffener 16 L-shaped caisson 17 Back stone input wall 18 Joint part 19 Tsum wall 20 Back stone input part 21 Back stone 31 Case 32 Joint 33 Land side 34 Back stone input frame 35 Mounting bracket 36 Backstone

Claims (1)

  Adjacent to the land side of the quay / revetment using L-shaped blocks, pile up a backstone so that it has a downward slope toward the land side from the quay / revetment, and then put a sand barrier on the backside stone. -In a structure for preventing landfill runoff from a quay or revetment in which landfill is buried, and a land portion on the land side at a certain distance from both longitudinal ends of the L-type block, After installing a lining stone into the lining stone input section formed between the lining stone input walls of adjacent L-shaped blocks, A structure to prevent the outflow of landfill from the quay and revetment, which is covered with a sand-proof sheet together with the back-filling stone input section, and back-filled soil is input from above.

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