JP2002212931A - Covering work for revetment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the structural stability and durability of covering work for preventing covering stones from being scoured due to wave overtopping into a harbor in revetment work for a breakwater. SOLUTION: In the covering work for revetment, surfaces of covering stone slopes 5A and 5B created on a back surface of a breakwater caisson 2 are covered with a concrete mat 21 manufactured of a cloth form. Plural wire ropes 30 are provided within the concrete mat 21 at prescribed intervals along the direction of extension of the revetment. The wire ropes 30 are inserted into a cylindrical net 31 extended approximately throughout the length, in a length-of-slope direction, of the inside of the concrete mat 21, one end of the wire rope 30 is anchored to the wall surface of the caisson 2, and the other end thereof is located on the slopes 5A and 5B for the purpose of anchorage of the lower end of the concrete mat 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a seawall covering work,
In particular, the present invention relates to a seawall covering work for improving the structural stability and durability of a concrete mat covering work to prevent scouring of the covering stone due to overtopping into a harbor in a seawall.

[0002]

2. Description of the Related Art Conventionally, breakwater revetments have been designed to have a structure and dimensions sufficient for anticipated waves and to maintain calm in a harbor. FIG. 6 is a cross-sectional view showing an example of a conventional breakwater embankment composed of a breakwater block hybrid embankment. In this breakwater embankment 50, a caisson 52 is installed on a waste stone foundation 51, a wave-dissipating block 53 having a predetermined slope is provided on the front of the caisson 52, and a covering stone 54 having a predetermined slope is built on the back. The peak height of this type of breakwater is generally determined based on the average high tide surface (HWL) taking into account the effect of overtopping on the port behind the breakwater.
However, it is possible that waves above the breakwater top will overtop and scour the cover stone on the back side of the caisson. Therefore, as shown in the figure, coating work for preventing scouring that covers the surface of the coating stone on the back side of the caisson is often performed. In addition to the asphalt mat work, a method of laying a cloth formwork along the slope on which the covering stone is piled and covering the inside with a concrete mat filled with concrete is used for this covering work.

[0003]

However, since the concrete used in the covering concrete work is plain concrete, the concrete between the slope and the top end face of the covering work is caused by uneven settlement of the slope. Cracks occur in the concrete at the bent portion 55a of the shoulder between the slopes, and in severe cases, the concrete of the mat is cut, and the concrete mat 55 on the slope is cut.
There is a possibility that B may be held only by friction with the slope. For this reason, a mat suspension and a supporter for supporting the mat from below are provided to prevent the concrete mat from sliding. However, since it is difficult to additionally construct a stable structure on a slope having only abandoned stones or the like, the concrete mat is often supported only by frictional resistance with the slope.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a revetment cladding work which achieves structural stability of a breakwater covering work.

[0005]

In order to achieve the above object, the present invention covers a surface of a covering stone slope constructed on the back of a breakwater caisson with a concrete mat formed by filling concrete in a cloth formwork. In the revetment covering work, the concrete mat is inserted at a predetermined interval along the revetment extension direction into a tubular net extending in the normal length direction of substantially the entire length in the concrete mat, and one end is connected to the caisson. It has a plurality of wire ropes fixed to the wall surface and the other end fixed to the lower end of the concrete mat located on the covering stone slope.

At this time, the height of the cylindrical net is approximately 1/2 of the mat thickness of the concrete mat filled with concrete, and the wire rope inserted through the cylindrical net has a thickness of the mat. It is preferable to dispose it at a substantially central position in the vertical direction.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a revetment covering apparatus according to the present invention. FIG. 1 shows a caisson 2 installed on a dumping stone foundation 1 and filled with filling sand 3 therein, a root solid block 4 and a covering stone slope 5 on the back of the caisson 2, and construction on the slope Revetment cladding 1
FIG. 2 is a schematic perspective view partially showing 0. [Structure of revetment cladding work] As shown in the figure, on the back side of a caisson 2 installed on a discarded stone foundation 1, a covering stone slope having a predetermined slope and a predetermined slope is formed to a predetermined height. 5 have been built. Further, a revetment covering work 10 is provided so as to cover the entire covering stone slope 5. The revetment covering work 10 is composed of a concrete mat 21 and a mortar mat 22 which are constructed on site using a cloth formwork 20. Of these, concrete mat 21
In the present embodiment, is laid over the entire top end face 5A of the covering stone slope 5 and the slope 5B in a range of a tide level of about -2.0 m from the lowest tide (LWL), and furthermore, a predetermined overlapping portion 22a ( In the present embodiment, a mortar mat 22 is laid down to the sea floor 23 with a length of 1.0 m).

The concrete mat 21 of the revetment cladding is a cast-in-place member having a mat thickness of about 300 mm by filling concrete into a cloth formwork 20, and a mortar mat 22 is similarly made of a cloth formwork. It is a cast-in-place member whose mat thickness becomes about 50 mm by filling mortar inside. In the present embodiment, these cloth mold frames 20 are formed in a bag-like form by connecting two woven fabrics made of polyester resin fibers with binding yarns (not shown) arranged at predetermined intervals. A frame (trade name: Tacom Matt) is used. The mat thickness at the time of completion of the concrete mat 21 is determined by the filling amount of the internal concrete, and a cloth form of each thickness is provided by previously determining the length of the binding yarn. In addition, the fiber used for the fabric mold is
Various woven fabrics can be used as long as they are general synthetic fibers having weather resistance.

[Structure of Concrete Mat] Here, the structure of the concrete mat 21 as a covering work will be described with reference to FIGS. FIG. 2 is a cross-sectional view showing a state in which the wire rope 30 is inserted through the entire concrete mat 21, FIG. 3 is a detailed view of a wire rope fixing end,
FIG. 4 is a schematic explanatory view showing an example of a means for holding the wire rope 30, and FIG. 5 is a layout diagram of each part such as a wire holding net 31, a concrete filling hole, etc. provided on the cloth formwork 20. .

Concrete is filled in a cloth formwork 20 spread on the top end face 5A and the slope face 5B of the covering stone slope 5,
The concrete mat 21 is completed. At this time, as shown in FIGS. 1 and 2, the concrete mat 21 is placed on the top end surface 5A and the upper part of the slope 5B, and the upper end 30a of the wire rope 30 accommodated in the mat is attached to the caisson wall surface 2a. Has been established. For this reason, even if the concrete mat 21 is cut at the bent shoulder 21a in the future, the concrete mat 21B is hung from the end of the mat 21A by several wire ropes 30, so that the concrete mat 21B is cut. Can be prevented from sliding down the slope 5B.

As shown in FIG. 2, the wire rope 30 accommodated in the concrete mat 21 extends over the entire length of the mat in the normal length direction (X direction).
1 (described below). The both ends 30a and 30b are, as shown in FIGS.
0a is fixed to the caisson wall surface 2a, and the lower end 30b is fixed to the mat end 21b via a predetermined anchor plate 35. In the present embodiment, the wire rope 30
Is used, but it is also preferable to use a resin-coated steel strand or the like to increase the corrosion resistance. Further, it is preferable that the wire diameter and the number of wires are appropriately determined according to the stability condition for preventing the concrete mat 21B from sliding on the slope.

[Means for Holding Wire Rope] Means for holding the wire rope 30 in the concrete mat will be described with reference to FIG. In this embodiment, the wire rope 30 is inserted into the wire holding net 31 in the present embodiment, and the position in the thickness direction and the longitudinal direction in the mat is held in the mat. In this embodiment, a resin net having a predetermined size is used for the wire holding net 31. The resin net is a net-like body manufactured by interweaving vinylon resin fibers in a lattice shape, and is sewn to a cloth frame in a substantially U-shape along the wire arrangement position when the raw fabric is sewn. As a result, the tubular body extending over the entire length of the cloth mold in the normal length direction (X direction) becomes the cloth mold 2.
0 is formed. The height of the wire holding net 31 is determined by the thickness (H) of the filled concrete mat 21.
Are set so that the height is 1/2 of the height. Thus, in a state where the wire rope 30 is inserted into the wire holding wire 31, the wire rope 30 can be located at a substantially central position in the thickness direction of the mat (see each drawing in FIG. 3).
The fiber used for the resin net may be any general synthetic fiber.

[Configuration of Wire Rope Fixing End] The configuration of the wire rope fixing end will be described with reference to FIG. FIG. 3A shows a fixing unit 30a on the wall surface of the caisson 2 at the upper end of the wire rope. As shown in the figure, a hole-in anchor 32 is attached to the caisson wall surface 2a in advance, and an eye nut 33 is screwed onto the hole-in anchor 32, and the eye nut 3
3, a loop-shaped end 30a of the wire rope 30 is fixed via a shackle 34. The anchor position of the caisson wall 2a is also set to be about half the height of the mat thickness H.

FIG. 3B shows the configuration of the wire rope anchoring end 30b at the lower end of the slope of the concrete mat 21B. As shown in FIG.
An eye bolt 36 is screwed into the center of the flange of an anchor plate 35 made of angle iron having a side of 300 mm. The loop end of the wire rope 30 is fixed to the eye bolt 36 via a shackle 37. The mat end 21b is installed on the upper end of the mortar mat 22 with a predetermined overlapping portion 22A.

[Layout Arrangement of Cloth Form] FIG. 5 is an arrangement diagram schematically showing the positional relationship of each part formed integrally with the cloth form 20. As shown in FIG. In the present embodiment, as shown in the drawing, a cloth mold 2 having a substantially square shape with a side of about 11 m in plan view.
When sewing No. 0, the wire holding net 31 is sewn to the form material over the entire length in the normal length direction (X direction).
The wire holding nets 31 are arranged at a pitch of about 2 m in the seawall extension direction (Y direction), and concrete filling holes 25 are arranged in the cloth portion therebetween at intervals of about 2 m in the normal length direction. . Concrete is filled using the concrete filling hole 25.

[Construction of Concrete Mat] In the construction of the covering work, it is preferable that the wire rope 30 is previously inserted into the tubular wire holding net 31 at the land yard. Then, the fabric form 20 into which the wire rope 30 is charged is carried into the site of the coating work, and the top end surface 5A
And it develops to the predetermined position on the slope 5B. Further, the ends 30a and 30b of the wire rope 30 are pulled out from the respective wire end take-out holes 24 (see FIG. 5) provided in the fabric form 20 and one end 30a is inserted into an anchor provided on the caisson wall surface 2a. The other end 30b is fixed to the anchor plate 35 at the lower end of the slope (see FIGS. 3A and 3B). From this state, the concrete filling hole 25 provided in the fabric form 20 is used to place the inside of the fabric form 20 at an appropriate position so that the thickness is substantially uniform from below the slope of the mat. Concrete is poured from the concrete filling hole 25. Concrete is usually poured from land using a concrete pump or the like. At this time, it is preferable that a part of the fabric form is held by a temporary suspending member such as a chain block or a suspending wire at a part of the covering work. Thereby, the lower end of the fabric form 20 is filled with concrete, and the weight of the fabric form 20 can be prevented from sliding down the slope.

Further, after completion, unequal settlement of the discarded stone foundation and the covering stone occurs, the concrete mat 21 is cut at the bent portion 21a of the slope, and the top end side and the slope side of the concrete mat are cut. In such a case, the wire rope 30 can surely hang the concrete mat 21B on the slope side, so that the concrete mat 21B can be prevented from sliding down the covering stone slope 5B.

[0018]

As is apparent from the above description, according to the present invention, it is possible to improve the structural stability and durability of a covering work for preventing scouring of covering stones on the backside of a breakwater due to waves overtopping the breakwater. This has the effect of improving the durability of the entire breakwater structure.

[Brief description of the drawings]

FIG. 1 is a partial sectional perspective view showing a breakwater structure (rear side) to which an embodiment of a seawall covering work according to the present invention is applied.

FIG. 2 is a schematic cross-sectional view showing an example of the seawall covering work of the present invention shown in FIG.

FIG. 3 is a partially enlarged cross-sectional view showing a fixing end of a wire rope used in the revetment cladding shown in FIG. 2;

FIG. 4 is a partial perspective view schematically showing a holding state of a wire rope by a wire holding net.

FIG. 5 is an allocation plan view showing an example of allocation of each part to a cloth mold.

FIG. 6 is a schematic sectional view showing an example of a conventional breakwater structure.

[Explanation of symbols]

 2 Caisson 5 Cover stone slope 5A Top end face 5B Slope 10 Coating work 20 Cloth formwork 21, 21A, 21B Concrete mat 21a Method shoulder bending part 30 Wire rope 30a, 30b Wire end 31 Wire holding net

Claims (2)

[Claims] Claims: 1. A seawall covering work in which a surface of a covering stone slope built on the back of a breakwater caisson is covered with a concrete mat formed by filling concrete in a fabric form, wherein the concrete mat extends in a seawall extending direction. At predetermined intervals along the length of the concrete mat, it is inserted into a cylindrical net extending almost the entire length in the normal length direction, one end is fixed to the caisson wall surface, and the other end is positioned on the covering stone slope. A seawall covering comprising a plurality of wire ropes fixed to the lower end of a concrete mat. 2. The height of the tubular net is approximately half the thickness of a concrete mat filled with concrete, and the wire rope inserted through the tubular net has a thickness of the mat. The revetment cladding according to claim 1, wherein the revetment is disposed at a substantially central position in the direction.