JP2007132064A - Joint closing structure for existing caisson revetment work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the suction of backfilling sand etc. by rapidly closing a joint, when an excessive gap is formed in the joint between adjacent caissons, for example, due to unevenness caused on a foundation, in existing caisson revetment work. <P>SOLUTION: A filter material storage hole 11 is formed along the height direction of the caisson 2 by partially cutting opposed side surfaces 2a of the adjacent caissons 2. In a tubular filter material 15, a filling stone 14 with a particle diameter of 1-2 cm which is housed in the hole 11 and infilled inside brings a part of an outer peripheral surface into close contact with the side wall surface 2a of the caisson, and makes the joint between the adjacent caissons 2 closed. The filter material 15 has its outside diameter set slightly smaller in dimension than the inside diameter of the hole 11. The joint closing structure comprises the hole 11 and the filter material 15. This can prevent the suction of the backfilling sand 3 etc. by closing the joint made by the unevenness etc. of the adjacent caissons 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joint blockage structure for an existing caisson revetment. In an existing caisson revetment, when an excessive gap occurs in the joint between adjacent caissons due to unevenness occurring in the foundation, the joint is quickly closed. In addition, the present invention relates to a joint blockage structure for an existing caisson revetment that can prevent sucking back sand and the like.

  Conventionally, in quay construction such as harbors, caisson revetment works as gravity structures in which concrete caissons (boxes) are continuously arranged on a rubble foundation and filled with sand filled in each caisson. Often built.

  However, in these caisson revetments, the land subsidence under the rubble foundation and unequal subsidence occurs in the foundation due to scouring, and excessive gaps are created in the joints between adjacent caissons. There is a situation in which sucking phenomenon (outflow to the sea area) of backfill sand and the like filling the back of the caisson (mountain side) occurs from the gap.

  In order to prevent the back sand from sucking out from the joint between the existing caissons, there is a countermeasure work such as covering the front (sea side) of the joint between adjacent caissons with a rubber plate. The surface must be cleaned to remove marine deposits, and these are underwater construction, which increases the cost of construction and, in the caisson revetment, the attached rubber plates are exposed to waves, so it is durable. There was a problem.

  Therefore, a repairable method (Patent Document 1) has been proposed in which joints between existing caissons are formed only by construction from the ground. In addition, there is also a joint material (Patent Document 2) in which a joint material made of an elastic body is inserted into a gap between caissons and brought into close contact with a concrete surface, and is elastically deformed between joints to block the joint. Proposed.

JP 2000-352035 A Japanese Patent Laid-Open No. 10-311015

  By the way, in the joint repair method disclosed in Patent Document 1, as repair work, concrete drilling from the top of the caisson, a protective tube into the drilled hole, insertion of a protective member, fluid filler into the tube All processes such as filling are performed on land. That is, a bag-like body such as a rubber tube is inserted in the hole cut so as to straddle the gap between the caissons, and the fluid filler is filled therein. ing. Further, a rubber frame or the like is inserted into the hole to protect the rubber tube.

  In the joint repair method disclosed in Patent Document 1, many processes are required from drilling to filling with a filler, and there are problems that the materials used are various and the construction is complicated. Further, even when in use, the main material of the fluid filler is a relatively poor durability material such as asphalt mastic, which causes a problem in the durability of the repaired portion. For this reason, there is a possibility that the repair must be performed again in a relatively short period.

  Moreover, since the cross-sectional shape of the tubular body made of the elastic body disclosed in Patent Document 2 is deformed so as to close the joint between the caissons, it is inserted between the joints and therefore is not exposed to waves. For this reason, although the durability of the member is improved, it is necessary to clean the caisson surface at the position where the pipe is installed in advance as described above to remove marine deposits and the like, and in the gap near the bottom of the caisson. Underwater work by divers and others is necessary to insert the tube securely. Therefore, the object of the present invention is to solve the problems of the above-described conventional technology, and by using a simple structure, it is possible to reliably close the joints between the existing caissons by the work from the land. It is to provide an occlusion structure.

  In order to achieve the above-mentioned object, the present invention cuts a part of the facing surface of the adjacent caisson side wall surface, and forms a filter material accommodation hole formed along the height direction of the caisson, and the inside of the filter accommodation hole. And a cylindrical filter material that closes a part of the outer peripheral surface to the caisson side wall surface and closes the joints of the adjacent caisson by a filling material that is housed in and filled inside.

  At this time, the cylindrical filter material is set to an outer diameter dimension slightly smaller than the inner diameter of the filter material accommodation hole, and a part of the outer peripheral surface of the cylindrical filter material is filled in the caisson side wall surface in a state where the filling material is filled. It is preferable to adhere.

  The cylindrical filter material is preferably configured by sewing a nonwoven fabric into a cylindrical shape. Furthermore, it is preferable to use a stone material having a particle diameter of 1 to 2 cm as the filling material.

  According to the present invention, it is possible to reliably prevent sucking of backfill sand from the gap generated in the caisson revetment by the joint blockage structure composed of a simple structure, and further, the caisson immovable settlement occurs and the gap is expanded. Therefore, the joint blockage effect can be maintained for a long time.

  Hereinafter, the following examples will be described with reference to the accompanying drawings as the best mode for carrying out the joint closing structure of the existing caisson revetment of the present invention.

  FIG. 1 is a perspective view showing a part of a revetment work by existing caissons 2, 2... Constructed on a rubble foundation 1. FIG. As shown in the figure, these caissons 2 are displaced due to uneven settlement of the rubble foundation 1 as a substructure, and adjacent joints are in an open state from the time of installation. Therefore, in order to prevent the backfill sand 3 from being sucked out from the gap between the caissons 2 to the sea 4 side, the joint closing structure 10 of the present invention is applied to the joint 5 between the caissons 2 and 2. Has been. In addition, in FIG. 1, the dimension of the joint 5 between the caisson 2 and the joint blockage structure 10 is expanded and shown with respect to the dimension as a structure of the caisson 2 for description.

  The joint closing structure 10 shown in FIG. 1 is provided in the vicinity of the back side of the caisson 2 in the depth direction, and includes substantially semicircular grooves 11 formed substantially vertically on the side wall surfaces 2a of the opposing caisson 2. The tubular filter material 15 is provided upright so as to be fitted along the filter housing hole 12, and the filling material 14 is densely filled in the tubular filter material 15.

  Hereinafter, a procedure for incorporating the joint closing structure 10 of the present invention into the joint 5 of the existing caisson 2 having a gap is described with reference to FIGS. At that time, the configuration of the cylindrical filter member 15 will be described with reference to FIGS. 3 and 4.

  FIG. 2A is a partial plan view schematically showing the joint 5 of the caisson 2 in which a gap is opened from a predetermined joint dimension for some reason. The opening of the joint 5 between the caissons 2 generated by the unequal settlement of the rubble foundation 1 is about several cm at most, and the present invention assumes a structure that enables this degree of joint closure. Therefore, the case where the entire caisson 2 revetment collapses greatly to the sea area due to a lateral flow phenomenon during an earthquake or the like is outside the scope of application of the present invention.

  First, in order to attach the joint closing structure 10 of the present invention between the caissons 2, as shown in the figure, it is constituted by a substantially semicircular groove 11 formed in the opposing side wall surface 2a of the existing caisson 2 and a gap. The filter housing hole 12 is formed. This filter housing hole 12 is installed on the upper surface of the caisson 2 so as to straddle the joint 5 between the opposite caissons 2, and attached to the tip of the long rod to attach a ring-shaped cutter of a predetermined diameter, While holding the long rod using a centering device (not shown), a substantially semicircular groove 11 is formed in the caisson side wall surface 2a so as to be lowered substantially vertically from the top surface to the bottom of the caisson 2 and between the caissons 2. It is a formed circular hole.

  In addition, although the diameter of this filter accommodation hole 12 changes with separation | separation of the opposing caisson 2, in this Example, the cutter diameter of the concrete core cutter to be used is (phi) 150-200mm according to the opening of the joint 5 between the caisson 2. scheduled. That is, since the average opening of the joint 5 between the caisson 2 is about several tens to 10 cm, the depth of the substantially semicircular groove 11 formed by scraping the concrete side wall surface 2a is about 50 mm or less. Set the diameter. At this time, since the depth of the substantially semicircular groove 11 is smaller than the minimum cover (usually 10 cm) of the reinforcing bar arranged in the caisson 2, the reinforcing bar is not exposed in the substantially semicircular groove 11 portion of the filter housing hole 12.

  In addition, since the drilling of the filter housing hole 12 is an operation of drilling the side wall surface 2a of the opposing caisson 2 in a substantially semicircular shape, a cutting device or the like that can cut or scrape the concrete side wall surface 2a. For example, in addition to a circular hole drilling device such as a core cutter, various cutting devices and hole drilling devices that can perform the same function can be used. It is also possible to use a cutter using a water jet that can be set so that the spray nozzle forms a circular orbit corresponding to the cutter diameter.

  FIG. 2B is a plan view showing a state in which the tubular filter material 15 is inserted into the filter housing hole 12 constituted by the open portion of the joint 5 of the caisson 2 and the substantially semicircular groove 11. FIG. 3A is a partial perspective view showing a part of the shape of the tubular filter material 15 shown in FIGS. 2B and 2C in an enlarged manner. In this embodiment, as the cylindrical filter material 15, a non-woven fabric having a thickness of about 5 mm using polypropylene resin fibers in which reinforcing wires are arranged along the vertical direction as shown in FIG. 3A is used. ing. Since high-density polyester yarn is used as the reinforcing wire, an increase in the tensile strength in the longitudinal direction can be expected. As a specific product of this cylindrical filter material, for example, there is Diabase HS (registered trademark) manufactured by Mitsubishi Chemical Corporation. When the river gravel is densely filled in the tubular filter material 15 as shown in FIG. 5B, the nonwoven fabric is slightly stretched in the circumferential direction. The diameter is slightly increased.

  In the present invention, as shown in FIG. 2C, the filling material 14 is placed in the cylindrical filter material 15 which is set to a slightly smaller outer diameter by the filter housing hole as shown in FIG. And the diameter of the tubular filter material 15 is increased, so that the tubular filter material 15 can be brought into close contact with the inner peripheral surface of the filter housing hole 12 that is initially drilled. Thereby, the clearance gap produced between the caissons 2 with the cylindrical filter material 15 can be obstruct | occluded completely, and the suction of the backfill sand 3 from this clearance gap can be prevented reliably. Since the cylindrical filter material 15 is elastically deformed, it can be inserted and used even if its outer diameter is slightly larger than the inner diameter dimension of the filter housing hole 12. The outer peripheral surface of 15 can be appropriately adhered to the inner peripheral surface of the filter housing hole 12.

  As the filling material 14, it is preferable to use a stone material such as river gravel whose individual particle shapes are relatively rounded as a material that does not damage the nonwoven fabric of the filter material during filling. As for the particle size, if the particle size distribution is about 1 to 2 cm and the particle size is in a predetermined range, the bulk volume is less likely to be reduced even if the filter material is densely packed in the filter, and the diameter of the filter material is increased. You can expect enough. A single-grain artificial stone such as an artificial lightweight aggregate is also preferable because of its good filling property and easy bulk volume. Moreover, if the particle diameters are relatively uniform and the filling property is good, recycled materials such as blast furnace slag and recycled crushed stone of waste concrete can also be used as the stone material of the present invention.

  FIG. 2B is a partial plan view showing a state in which the filter housing hole 12 is closed using a modification of the tubular filter material 15. As shown in FIG. 4A, the flat filter material 16 is formed by extending the both ends of two flat nonwoven fabrics 17 and 17 made of the same material as the cylindrical nonwoven fabric shown in FIG. The cylindrical filter material 15 is sewn in the direction, and in the initial state, as shown in FIG. The flat filter material 16 is inserted into the joint 5 of the caisson 2 where the substantially semicircular groove 11 is formed, and the filling material 14 is filled between the two nonwoven fabrics 17 and 17. Then, as shown in FIGS. 2 (d) and 4 (b), the sewn portion 16a on the side of the filter material 16 is positioned in the gap portion of the joint 5 of the caisson 2, and the filling material 14 is filled. The portion with the expanded cross section forms a substantially circular cross section along the inner peripheral surface of the substantially semicircular groove 11 of the filter housing hole 12 and is in close contact with the inner peripheral surface of the filter housing hole 12. Thereby, also in this modification, the same effect as the cylindrical filter material 15 mentioned above can be acquired. Furthermore, as another modification of the cylindrical filter material 15, one flat filter material having a predetermined width is folded in half in the longitudinal direction so as to have a half-width dimension, and an end portion along the longitudinal direction is sewn. It may be cylindrical.

  Next, a construction method for joint blockage will be described. As described above, first, the filter housing hole 12 is formed by drilling from the upper surface to the bottom of the caisson 2 so as to straddle the caisson joint 5 with the concrete core cutter. Then, a pipe (not shown) slightly longer than the depth of the filter housing hole 12 is inserted into the tubular portion of the tubular filter material 15, and the tubular filter 15 is inserted into the filter housing hole 12 together with the pipe in the inserted state. Insert to the bottom inside. Thereafter, while dropping the filling material 14 from the opening at the top of the pipe, only the pipe is pulled up to fill the filling material 14 from the bottom to the top surface of the filter housing hole 12. In addition, it is preferable that the pipe to be used has a structure in which a plurality of pipes having a predetermined length are jointed. Thereby, when filling the filling material 14, when the pipe is pulled up with the filling operation, it can be removed at the connection position of the pipe, so that the charging position of the filling material 14 is kept at a substantially constant height. There is an advantage that the filling material filling operation can be performed easily.

The state explanation perspective view which showed the installation state of the existing caisson in which the joint closure structure of the existing caisson revetment of this invention was integrated. The construction sequence diagram which showed typically the construction procedure of the joint blockage structure of this invention. The fragmentary perspective view which showed the partial shape of the cylindrical filter material. The fragmentary perspective view which showed the partial shape of the modification of a cylindrical filter material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rubble foundation 2 Caisson 3 Backfill sand 10 Joint block structure 12 Filter accommodation hole 14 Filling material 15 Cylindrical filter material 16 Flat filter material 17 Nonwoven fabric

Claims (4)

  A part of the facing surface of the adjacent caisson side wall is cut, a filter material accommodation hole formed along the height direction of the caisson, and a filling filled in the filter accommodation hole. An existing caisson revetment joint blockage structure comprising: a cylindrical filter material that closes a part of the outer peripheral surface of the caisson side wall surface with a material and blocks the joint of the adjacent caisson.   The cylindrical filter material is set to have an outer diameter that is slightly smaller than the inner diameter of the filter material accommodation hole, and a part of the outer peripheral surface of the cylindrical filter material is in close contact with the caisson side wall surface in a state filled with the filling material. The joint closing structure for an existing caisson revetment according to claim 1.   The joint closure structure of the existing caisson revetment according to claim 1, wherein the tubular filter material is formed by sewing a nonwoven fabric into a tubular shape.   The joint filling structure of the existing caisson revetment according to claim 1, wherein the filling material is a stone having a particle diameter of 1 to 2 cm.

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