JP5288201B2 - Impact resistance reinforcement method and impact resistance reinforcement structure for existing caisson - Google Patents

Description

  The present invention relates to an impact-resistant reinforcing method and an impact-resistant reinforcing structure for an existing caisson for performing impact-resistant reinforcement on a wave-dissipating block-covered caisson breakwater or a seawall.

  In the case of breakwater-block-covered caisson-type breakwaters and revetments, many cases of damage have been reported in which the wave-dissipating block moves due to the force of waves during high waves and collides with the caisson wall, causing cracks and holes. Yes. An example of the damage situation in a general caisson type breakwater is shown in FIG. FIG. 9 is a schematic diagram showing how the wave-dissipating block collides with the caisson.

  A general breakwater block type caisson breakwater is constructed by constructing a breakwater body 10 on a mound 20 laid on the seabed, and a wavebreak block 50 is placed on the side where the waves of the breakwater body 10 collide (for example, the open ocean side). It has a stacked structure. The breakwater main body 10 has a caisson 13 installed on a mound 20 laid on the seabed, and a filling material 14 such as sand is filled in the caisson 13, and a lid concrete 12 and an upper concrete 11 are placed on the upper part of the caisson 13. (See FIG. 2).

  In such a caisson-type breakwater, when high waves are generated due to the influence of a typhoon or the like, the wave-dissipating block 50 is moved by the energy of the waves and collides with the breakwater main body 10 as shown in FIG. There is a risk of scratching. If the caisson wall 15 is perforated, the filling material (not shown) filled in the caisson 13 flows out to reduce the weight of the caisson 13, thereby reducing the stability against breakwater sliding.

  As a method for improving the impact resistance of the existing caisson 13, the following two methods can be considered. FIG. 10 is a schematic diagram showing a first example of a conventional impact resistance reinforcing method, and FIG. 11 is a schematic diagram showing a second example of the conventional impact resistance reinforcing method.

  As shown in FIG. 10, the first impact resistance reinforcing method is to temporarily remove the wave-dissipating block 50 installed outside the caisson wall 15, and cast concrete so that the concrete thickness of the caisson wall 15 increases. The reinforcing wall 200 is formed by adding a cushioning material or a steel plate to the front surface of the caisson wall 15.

  As shown in FIG. 11, the second impact-resistant reinforcement method temporarily removes the upper concrete 11 placed on the upper part of the caisson 13 and removes the filler 14 and replaces the filler 14 with concrete 220. Or the iron plate 210 is attached to the inner surface of the caisson wall 15.

  Conventionally, various shear reinforcement methods for general reinforced concrete structures have been proposed (see Patent Document 1). In the technique described in Patent Document 1, a hole having a predetermined depth is drilled at a predetermined position of a reinforced concrete structure to be reinforced, and a rod-shaped reinforcing member is inserted into the hole, and then a self-curing filler is filled. It is what you do.

JP 2002-275927 A

  However, various disadvantages may occur in the conventional method described above. That is, in the first example of the conventional impact resistance reinforcing method, the work of removing the wave-dissipating block 50 is necessary, and the cost increases. Moreover, during the period when the wave-dissipating block 50 is removed, the breakwater is in an unstable state against waves. Furthermore, the wave-dissipating block 50 is in a stable state due to subsidence due to long-term waves and meshing of the wave-dissipating blocks 50, but by re-installing the wave-dissipating block 50, it was in a very stable state. The wave-dissipating block 50 returns to the initial unstable state.

  Moreover, in the 2nd example of the conventional impact-resistant reinforcement method, the removal work of the upper concrete 11 and the lid concrete 12 and the extraction work of the filling material 14 are required, and cost rises. Moreover, the breakwater is in an unstable state against waves during the period in which the upper concrete 11 is removed and the filling material 14 is removed.

  In addition, in the structure described in Patent Document 1, in a structure such as a reinforced concrete foundation, when the existing structure cannot secure sufficient safety against shear failure, only the shear strength is increased by increasing the amount of reinforcing bars. It is to improve. Therefore, as in the present invention, in a wall-shaped reinforced concrete structure, it is not possible to suppress bending deformation and improve resistance to punching shear failure. In addition, in the basic concrete that is the subject of the technique described in Patent Document 1, the reinforcing bars of the column members are usually fixed, or there are shear reinforcing bars installed at the time of new construction. It is not realistic to insert a reinforcing member from Furthermore, considering that the self-curing filler is poured, it is impossible to reinforce the target structure in the lateral direction.

  Moreover, the upper structure of a general wall structure has the superstructure of reinforced concrete, or the shear reinforcement reinforcement is arrange | positioned in the reinforcement of the wall itself, and it is difficult to perform reinforcement construction. In addition, there is a case where the upper concrete is not present in a wall portion of a structure such as a waterway or a semi-underground road, but in such a structure, there is no need for impact resistance reinforcement in the first place. On the other hand, the caisson wall has upper concrete on its upper part, but since unreinforced concrete is usually used, there is no restriction on drilling. Further, the caisson wall is generally not provided with a shear reinforcing bar, and a reinforcing member can be inserted into the caisson wall.

  The present invention has been proposed in view of the above-described circumstances, and it is not necessary to remove the wave-dissipating block disposed on the front surface of the caisson wall, to remove the upper concrete, and to remove the filling material at low cost. An object of the present invention is to provide an impact-resistant reinforcing method and an impact-resistant reinforcing structure for an existing caisson capable of performing impact-resistant reinforcement on a caisson-type breakwater or revetment covered with a wave-dissipating block.

The impact-resistant reinforcing method and impact-resistant reinforcing structure of the existing caisson of the present invention have the following characteristics in order to achieve the above-described object.
That is, the impact-resistant reinforcement method for an existing caisson of the present invention is a method for impact-resistant reinforcement for a wave-dissipating block-covered caisson breakwater and a revetment, and is a reinforced concrete wall constituting the outer surface of the existing caisson The step of drilling the reinforcing member insertion hole from the upper side of the (caisson wall) toward the lower inside of the reinforced concrete wall (caisson wall), and the bending resistance in the reinforcement member insertion hole and the resistance to punching shear failure Including a step of inserting a reinforcing member for improving the strength and a step of filling a filler in the reinforcing member insertion hole.

  In addition, it is preferable to include a step of performing a roughening process on the inner wall surface of the reinforcing member insertion hole after the reinforcing member insertion hole is drilled.

  The impact-resistant reinforcement structure of the existing caisson of the present invention is an impact-resistant reinforcement structure for the caisson-type breakwater and revetment of a wave-dissipating block covering, from above the reinforced concrete wall (caisson wall) constituting the outer surface of the existing caisson, Reinforcing member insertion hole perforated downward in the interior of the reinforced concrete wall (caisson wall) and reinforcement for insertion into the reinforcing member insertion hole to suppress bending deformation and to improve the resistance to punching shear failure A member and a filler filled in the reinforcing member insertion hole are provided.

  According to the impact-resistant reinforcement method and impact-resistant reinforcement structure of the existing caisson of the present invention, the reinforced concrete wall (caisson wall) that forms the outer surface of the existing caisson without moving the wave-dissipating block or removing the filling material The reinforcement member insertion hole is drilled from the upper side of the reinforced concrete wall (caisson wall) to the lower inside, and the reinforcement member is inserted into the reinforcement member insertion hole and filled with a filler. Further, it is possible to suppress bending deformation and improve the resistance to punching shear fracture. Furthermore, since the wave-dissipating block is not moved, the stable state of the wave-dissipating block is not disturbed, and the impact-proof reinforcement work can be performed while the breakwater and the revetment remain stable against waves.

  In addition, the roughening treatment is performed in the reinforcing member insertion hole, whereby the adhesive force of the reinforcing member is further strengthened.

The schematic diagram which shows the procedure of the impact-resistant reinforcement method of the existing caisson which concerns on embodiment of this invention. The schematic diagram of the caisson-type breakwater of the wave-dissipating block covering type which applies the impact-resistant reinforcement method and the impact-resistant reinforcement structure of the existing caisson concerning embodiment of this invention. The schematic diagram which shows a part of structure of a caisson wall. The cross-sectional schematic diagram (before construction) which shows the specific example of the impact-resistant reinforcement structure of the existing caisson. The cross-sectional schematic diagram which shows the specific example of the impact-resistant reinforcement structure of the existing caisson (1st Embodiment). The cross-sectional schematic diagram which shows the specific example of the impact-resistant reinforcement structure of the existing caisson (2nd Embodiment). The cross-sectional schematic diagram which shows the specific example of the impact-resistant reinforcement structure of the existing caisson (3rd Embodiment). The cross-sectional schematic diagram which shows the specific example of the impact-resistant reinforcement structure of the existing caisson (4th Embodiment). The schematic diagram which shows a mode that a wave-dissipating block collides with a caisson. The schematic diagram which shows the 1st example of the conventional impact-resistant reinforcement method. The schematic diagram which shows the 2nd example of the conventional impact-resistant reinforcement method.

<Outline of impact resistance reinforcement method and impact resistance reinforcement structure>
Hereinafter, with reference to the drawings, an embodiment of an impact resistance reinforcement method and an impact resistance reinforcement structure of an existing caisson according to the present invention will be described. FIG. 1 is a schematic diagram illustrating a procedure of an impact resistance reinforcing method for an existing caisson according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a caisson type breakwater of a wave-dissipating block covering type to which the impact resistance reinforcement method and impact resistance reinforcement structure of an existing caisson according to an embodiment of the present invention are applied, and FIG. 3 is a diagram of the structure of a caisson wall. It is a schematic diagram which shows a part. 3A is a schematic cross-sectional view of the caisson wall, FIG. 3B is a schematic vertical cross-sectional view of the caisson wall, and FIG. 3C is a schematic side cross-sectional view of the caisson wall.

  The impact-resistant reinforcement method and the impact-resistant reinforcement structure of the existing caisson according to the embodiment of the present invention are for performing impact-resistant reinforcement on the wave-dissipating block-covered caisson-type breakwater and revetment, and in particular, bending deformation In addition, it is possible to improve the resistance to punching shear fracture. In the following embodiment, a caisson type breakwater will be described, but the present invention can of course be applied to a wave-dissipating block-covered caisson type revetment.

<Dissipating block-covered caisson breakwater>
As shown in FIG. 2, the wave-dissipating block-covered caisson type breakwater to which the impact-resistant reinforcement method and the impact-resistant reinforcement structure of the existing caisson according to the embodiment of the present invention are applied is formed on the mound 20 laid on the seabed. The main body 10 is constructed, and a wave-dissipating block 50 is stacked on the side where the waves of the breakwater main body 10 collide (for example, the open ocean side). The breakwater main body 10 has a covering stone 30 laid on a mound 20 laid on the seabed, a caisson 13 is set on the covering stone 30, and a filling material 14 such as sand is filled inside the caisson 13. The lid concrete 12 and the upper concrete 11 are placed on the upper part of the caisson 13. A root block 40 is installed on the side surface of the lower end portion of the caisson 13. The caisson 13 has a caisson wall 15 made of reinforced concrete as an outer shell, and an inner filler 14 is filled in the outer shell.

<Procedure for impact resistance reinforcement method>
Here, the structure of the caisson wall 15 on the front side can be considered as a surface member that is long in the vertical direction when the space between the two partition walls is considered. And as a failure mode, the bending failure of a short side direction, the bending failure of a long side direction, and a punching shear failure can be assumed. Among these failure modes, it can be considered that the punching of the caisson wall 15 in the wave-dissipating block 50 is particularly affected by the punching shear failure. Therefore, in the impact resistance reinforcement method for the existing caisson according to the embodiment of the present invention, as shown in FIG. 3, in the caisson wall 15 for the purpose of suppressing bending deformation and improving the resistance to punching shear failure, A reinforcing member is embedded in the interior surrounded by the reinforcing bars.

  That is, inside the caisson wall 15, as shown in FIGS. 3A to 3C, a reinforcing bar 60 is provided on the front side facing the wave-dissipating block 50 and on the back side where the wave-dissipating block 50 is the other side. Is arranged. The reinforcing bar 60 includes a main reinforcing bar and a power distribution reinforcing bar that is substantially orthogonal to the main reinforcing bar. In the caisson wall 15 having such a structure, a region where the reinforcing bar 60 is not arranged exists between the reinforcing bar 60 arranged on the front side and the reinforcing bar 60 arranged on the back side. By embedding a reinforcing member, bending deformation can be suppressed and the resistance to punching shear failure can be improved.

  The impact resistance reinforcing method for the existing caisson according to the present embodiment is performed in the procedure shown in FIGS. When the wave-dissipating block 50 is moved by the energy of waves and collides with the breakwater main body 10 with respect to the caisson 13 before the impact resistance reinforcement is performed, there is a possibility that a hole is formed in the caisson wall 15 (see FIG. 1A). ). Therefore, first, the reinforcing member insertion hole 80 is drilled from above the upper concrete 11 toward the lower interior of the caisson wall 15 by using a drilling device 70 such as a concrete core cutter or a crawler drill (FIG. 1B). Subsequently, a roughening bit (not shown) is attached to the tip of the rod 90, and the rod 90 is rotated to thereby roughen the inner surface of the reinforcing member insertion hole 80 (FIG. 1 (c)). . The roughening process may be omitted depending on the shape and properties of the reinforcing member 100 inserted into the reinforcing member insertion hole 80.

  Then, the reinforcing member 100 is inserted into the reinforcing member embedded region (see FIG. 3) of the reinforcing member insertion hole 80 from above the reinforcing member insertion hole 80 (FIG. 1D). Subsequently, the filling nozzle 110 is inserted into the upper portion of the reinforcing member insertion hole 80 (FIG. 1E), and the filler 120 is filled into the gap of the reinforcing member insertion hole 80 (FIG. 1F). The filler 120 is preferably a self-curing type, for example, non-shrink mortar.

<Impact-resistant reinforcement structure>
Next, a specific configuration of the existing caisson impact-resistant reinforcement structure according to the embodiment of the present invention will be described. 4-8 is a cross-sectional schematic diagram which shows the specific example of the impact-resistant reinforcement structure of the existing caisson. 4 to 8 show caisson walls located on the wave-dissipating block side.

  The impact-resistant reinforcing structure of the existing caisson according to the embodiment of the present invention is constructed by the above-described procedure, but the diameter, depth, position, etc. of the perforations are different depending on the reinforcing member 100 to be used. Hereinafter, the impact-resistant reinforcement structure of the existing caisson according to the embodiment of the present invention will be described for each reinforcing member 100 to be used.

  FIG. 4 is a schematic cross-sectional view of the caisson wall before impact resistance reinforcement. As shown in FIG. 4, reinforcing bars 60 are arranged on both opposing wall surfaces inside the caisson wall 15 before impact resistance reinforcement. In the example shown in FIG. 4, a plurality of reinforcing bars 60 are arranged in the longitudinal direction and the longitudinal direction of the caisson wall 15.

<First Embodiment>
The impact-resistant reinforcing structure according to the first embodiment is a reinforcing member in which a plurality of reinforcing bars 130a are arranged in a substantially vertical direction. That is, in the impact-resistant reinforcement structure according to the first embodiment, as shown in FIG. 5, the reinforcing member insertion holes 80 are drilled downward from the upper part of the caisson wall 15 at a predetermined interval. Reinforcing bars 130a are respectively inserted therein, and fillers (not shown) are filled in the gaps of the reinforcing member insertion holes 80.

<Second Embodiment>
The impact-resistant reinforcement structure according to the second embodiment is obtained by inserting a plurality of H-shaped steels 130b in a substantially vertical direction as a reinforcing member. That is, in the impact-resistant reinforcement structure according to the second embodiment, as shown in FIG. 6, the reinforcing member insertion holes 80 are drilled downward from the upper part of the caisson wall 15 at predetermined intervals. The H-shaped steel 130b is inserted into each of them, and a filler (not shown) is filled in the gaps of the reinforcing member insertion holes 80. In order to increase the fixing power, it is preferable to use H-shaped steel with protrusions having a plurality of protrusions on the outer surface of the flange and both surfaces of the web. In addition to the H-shaped steel 130b, various shape steels such as equilateral angle steel and groove steel may be used as the reinforcing member.

<Third Embodiment>
The impact-resistant reinforcing structure according to the third embodiment is obtained by arranging a plurality of mesh-like reinforcing bars 130c arranged in a substantially vertical direction and a substantially horizontal direction as reinforcing members. That is, in the impact-resistant reinforcement structure according to the third embodiment, as shown in FIG. 7, the reinforcing member insertion holes 80 are drilled downward from the upper part of the caisson wall 15 at predetermined intervals. At this time, a series of transverse reinforcing member insertion holes 80 are formed as a whole so that adjacent reinforcing member insertion holes 80 overlap each other. Then, a mesh-like reinforcing bar 130 c in which reinforcing bars 60 are arranged in two orthogonal directions is inserted into the reinforcing member insertion hole 80, and a filler (not shown) is filled in the gap portion of the reinforcing member insertion hole 80.

<Fourth Embodiment>
The impact-resistant reinforcing structure according to the fourth embodiment has a fiber reinforcing sheet 130d inserted as a reinforcing member. That is, in the impact-resistant reinforcement structure according to the fourth embodiment, as shown in FIG. 8, the reinforcing member insertion holes 80 are drilled downward from the upper part of the caisson wall 15 at a predetermined interval. At this time, the reinforcing member insertion holes 80 that form a horizontal series as a whole are formed such that adjacent reinforcing member insertion holes 80 overlap each other. Then, the fiber reinforcing sheet 130 d is inserted into the reinforcing member insertion hole 80, and a filler (not shown) is filled in the gap portion of the reinforcing member insertion hole 80. As the fiber reinforcing sheet 130d, a carbon fiber sheet, an aramid fiber sheet, or the like can be used.

DESCRIPTION OF SYMBOLS 10 Breakwater main body 11 Upper concrete 12 Cover concrete 13 Caisson 14 Filling material 15 Caisson wall 20 Mound 30 Cover stone 40 Root solid block 50 Wave breaking block 60 Rebar 70 Punching device 80 Reinforcement member insertion hole 90 Rod 100 Reinforcement member 110 Filling nozzle 120 Filler 130a Reinforcing bar 130b H-shaped steel 130c Mesh-like reinforcing bar 130d Fiber reinforcing sheet 200 Reinforcing wall 210 Iron plate 220 Concrete

Claims (3)

A method for impact-resistant reinforcement of a wave-dissipating block-covered caisson-type breakwater and revetment,
A step of drilling a reinforcing member insertion hole from above the reinforced concrete wall constituting the outer surface of the existing caisson, toward the lower inside of the reinforced concrete wall;
Inserting a reinforcing member for suppressing bending deformation and improving resistance to punching shear fracture in the reinforcing member insertion hole;
Filling the reinforcing member insertion hole with a filler;
An impact-resistant reinforcing method for an existing caisson, characterized by comprising:   2. The impact resistance reinforcing method for an existing caisson according to claim 1, further comprising a step of roughening the inner wall surface of the reinforcing member insertion hole. An anti-shock reinforcement structure for a wave-dissipating block-covered caisson breakwater and revetment,
Reinforcing member insertion holes drilled from above the reinforced concrete wall constituting the outer surface of the existing caisson, toward the lower inside of the reinforced concrete wall;
A reinforcing member for inserting into the reinforcing member insertion hole to suppress bending deformation and to improve the resistance to punching shear fracture;
A filler filled in the reinforcing member insertion hole;
An existing caisson impact-resistant reinforcement structure characterized by comprising

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