JP2012097433A - Reinforcement body of concrete structure, reinforcement structure of concrete structure, and reinforcement method of concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement body and a reinforcement structure of a concrete structure, capable of efficiently reinforcing the concrete structure which is difficult to reconstruct.SOLUTION: A reinforcement body 2 of the concrete structure (dam body C of a dam) includes a PC cable 10, a block body 20 and a tensile force transmission body 30, and a reinforcement structure 1 comprises a plurality of the reinforcement bodies 2. One end 11 and the other end 12 of the PC cable 10 are respectively fixed to the part of ground G in drilling holes H1 and H2. The block body 20 is arranged at the upper end part of the dam body C, and curves and supports the intermediate part of the PC cable 10 so as to be convex vertically upwards. A support block (tensile force transmission body) 30 is interposed between the block body 20 and the upper end face of the dam body C, maintains the PC cable 10 in a tense state, and also transmits a part of the tensile force of the PC cable 10 to the upper end face of the dam body C.

Description

  The present invention relates to a method for reinforcing a concrete structure, such as a dam, a breakwater, an underground station building, or the like, which reinforces a concrete structure that is difficult to renovate with a PC cable, and a reinforcing body for a concrete structure constructed by the reinforcing method. The present invention relates to a reinforcing structure for a concrete structure including a plurality of reinforcing bodies.

  In recent years, based on the lessons learned from the Great Hanshin-Awaji Earthquake, it has been recommended to reinforce concrete structures such as existing dams, breakwaters, and underground station buildings that cannot be easily rebuilt. For example, Patent Documents 1 to 3 propose a structure in which a concrete structure is reinforced by an anchor structure using a PC cable.

  FIG. 5 is a schematic view of a reinforcement body of a concrete structure formed by applying an anchor structure to a dam body C (concrete structure). In this reinforcing body, the PC cable 10 is inserted into the hole H that penetrates the dam body C and reaches the ground G, and fixes one end of the PC cable 10 to the ground G and fixes the other end of the PC cable 10 to the ground G. It is fixed to the upper part of the dam body C by means of the tool D. By the reinforcing body having such a configuration, the dam body C can be reinforced by applying a compressive force to the dam body C.

JP 2010-174553 A JP 2010-174554 A JP 2010-174555 A

  However, in the reinforcement body of the concrete structure to which the above-described anchor structure is applied, it takes a little time to install the fixing tool composed of a plurality of members. In particular, when a huge concrete structure such as a dam is reinforced, the number of reinforcing bodies also increases. Therefore, it is desired to improve the construction efficiency of each reinforcing body, thereby improving the construction efficiency of the reinforcing structure.

  The present invention has been made in view of the above circumstances, and one of its purposes is a concrete structure reinforcement body that can be efficiently constructed, and a reinforcement structure of a concrete structure comprising a plurality of the reinforcement bodies. Is to provide. Another object of the present invention is to provide a method for reinforcing a concrete structure for efficiently reinforcing a concrete structure that is difficult to be remodeled.

  The reinforcement body of a concrete structure of the present invention relates to a reinforcement body of a concrete structure that reinforces a concrete structure by applying a tension force of a strained PC cable as a compressive force to the concrete structure. The concrete structure to be reinforced has two drilling holes that reach the ground through the concrete structure from its upper end. The reinforcing body of the concrete structure of the present invention reinforces the concrete structure using these drilling holes, and includes a PC cable, a block body, and a tension transmission body. One end of the PC cable provided in the reinforcing body of the present invention is fixed to the ground portion in one drilling hole, and the other end is fixed to the ground portion in the other drilling hole. The block body is a member disposed at the upper end portion of the concrete structure, and has a curved portion that supports the middle portion of the PC cable by curving it so as to protrude vertically upward. The tension transmission body is interposed between the block body and the upper end surface of the concrete structure to maintain the PC cable supported by the block body in a tensioned state, and the tension of the PC cable. It is a member that transmits a part to the upper end surface of the concrete structure.

  According to the reinforcing body for a concrete structure of the present invention, the concrete structure can be reinforced without using a fixing tool. Therefore, it is possible to reduce the time and labor for constructing a fixing tool composed of a plurality of members, and it is possible to reduce the overall number of parts of the reinforcing body.

  Further, according to the reinforcing body of the present invention, it is possible to save the trouble of constructing a rust prevention structure for the fixing tool. Since the fixing tool is usually made of an iron-based material, a rust prevention structure that covers the periphery of the fixing tool is essential. On the other hand, the reinforcing body of the present invention that does not use a fixing tool does not require a rust prevention structure for the fixing tool. Of course, in the reinforcing body of the present invention, it is preferable to construct a rust prevention structure around the block body that tensions the PC cable, but the rust prevention structure may be very simple compared to the rust prevention structure of the fixing tool. . That is, even if the rust prevention structure is constructed in the reinforcing body of the present invention, the labor for constructing the rust prevention structure is much smaller than the labor for constructing the rust prevention structure of the conventional fixing tool.

  Furthermore, since the reinforcing body of the present invention has a simple configuration that does not use a fixing tool, there is an advantage that it is excellent in economic efficiency.

  As one form of the reinforcing body of the concrete structure of the present invention, the curved portion may be formed by a curved bowl-shaped guide body through which the PC cable is guided. In that case, it is preferable that the guide body is embedded in the block body so that the inner peripheral surface thereof is exposed at the upper end surface of the block body.

  By forming the curved portion with the guide body, the intermediate portion of the PC cable can be disposed on the block body simply by placing the intermediate portion of the PC cable on the guide body exposed from the concrete structure. The guide body can be made of steel or polyethylene.

  As one form of the reinforcing body of the concrete structure of the present invention, the curved portion may be formed by a curved pipe body through which the PC cable is inserted. In that case, it is preferable that the tubular body is embedded in the block body.

  By forming the bending portion with the tubular body, the PC cable can be bent with high accuracy. Further, the curved PC cable can be protected from the outside. This tubular body can be composed of a steel pipe or a polyethylene pipe.

  As one form of the reinforcing body of the concrete structure of the present invention, the PC cable is preferably fixed to the curved portion by a grout.

  According to the said structure, the movement of the PC cable with respect to a bending part can be suppressed. As a result, it is possible to prevent the outer peripheral surface of the PC cable from being rubbed and damaged by the curved portion.

  As one form of the reinforcing body of the concrete structure of the present invention, the tension transmitting body may be a jack that lifts the block body from the upper end surface of the concrete structure.

  As shown in the reinforcing method of the concrete structure of the present invention described later, in order to construct the reinforcing body of the concrete structure of the present invention, a jack for lifting the block body from the upper end surface of the concrete structure is used. If this jack is used as it is as a tension transmission body of the reinforcing member of the present invention, the PC cable can be re-tensioned quickly by the jack as necessary.

  As one form of the reinforcing body of the concrete structure of the present invention, the tension transmitting body may be a support block interposed between the block body and the upper end surface of the concrete structure.

  According to the said structure, after constructing | assembling the reinforcement body of this invention concrete structure using a jack, even if the jack is removed, predetermined compression force can be provided to a concrete structure. In this case, the jack can be reused for another purpose. For example, when a plurality of reinforcing bodies are formed on one concrete structure, each reinforcing body can be constructed sequentially with a small number of jacks. Of course, the removed jack can be used for purposes other than constructing the reinforcing body of the present invention.

  As one form of the reinforcing body of the concrete structure of the present invention, the PC cable is preferably a multi-cable.

  If it is a multi-cable in which a plurality of strands obtained by twisting a plurality of strands are further twisted and accommodated in a sheath, the plurality of strands can be handled integrally. By handling a plurality of strands as one body, it is possible to reduce variations in the tension force introduced into each strand, and to avoid variations in the compressive force applied to the concrete structure.

  When the concrete structure is actually reinforced using the above-described concrete structure reinforcing body of the present invention, it is preferable to use a plurality of the reinforcing bodies. That is, a reinforcing structure for a concrete structure formed by providing a plurality of reinforcing bodies of the present invention in one concrete structure.

  There is a limit to the compressive force that can be applied to concrete structures with a single reinforcement. Therefore, it is preferable to construct a reinforcing structure of the concrete structure with a plurality of reinforcing bodies so that a desired compressive force can be applied to the concrete structure.

  When the concrete structure for constructing the reinforcing structure is a dam, a plurality of the reinforcing bodies of the present invention are preferably juxtaposed in the width direction of the dam.

  By arranging reinforcements in the width direction of the dam, the entire dam can be reliably reinforced. Here, the width direction of the dam is the direction of the river width.

On the other hand, the method for reinforcing a concrete structure of the present invention is a method for reinforcing a concrete structure for reinforcing a concrete structure by applying a tension force of a tensioned PC cable as a compressive force to the concrete structure, The following steps are provided.
-The process of forming two drilling holes that penetrate the concrete structure from the upper end of the concrete structure and reach the ground.
・ A step of placing a jack at the upper end of the concrete structure.
A step of arranging a block body having a curved portion that is curved so as to protrude vertically upward on the jack.
A step of arranging an intermediate portion of the PC cable in the curved portion and fixing one end and the other end of the PC cable to a ground portion in different drilling holes.
The step of lifting the block body vertically upward with the jack and tensioning the PC cable to which both ends are fixed.
By passing through the above process, a block body is pulled down toward a concrete structure with a part of tension of a PC cable, and compressive force is given to a concrete structure.

  According to the above-described method for reinforcing a concrete structure of the present invention, it is possible to construct a reinforcing body and a reinforcing structure of the concrete structure of the present invention that can reinforce the concrete structure without using a fixing tool.

  As a form of the reinforcing method of the concrete structure of the present invention, further comprising a step of removing a jack by interposing a support block between a block body lifted vertically upward and an upper end surface of the concrete structure. preferable. In this case, a compressive force is applied to the concrete structure via the support block.

  According to the said structure, the reinforcement body and reinforcement structure of this invention concrete structure which can continue providing compressive force to a concrete structure even if a jack is removed can be constructed | assembled.

  According to the reinforcing body and the reinforcing structure of the concrete structure of the present invention, the concrete structure can be reinforced without using a fixing tool.

It is the schematic of the water storage dam reinforced with the reinforcement structure which concerns on Embodiment 1. FIG. It is the schematic which shows the installation state of the reinforcement structure in the upper end surface vicinity of the dam body of a water storage dam, Comprising: (A) is the schematic of the reinforcement structure corresponding to FIG. 1, (B) is a reinforcement structure different from (A). FIG. (A)-(C) is explanatory drawing which shows the construction method of each reinforcement body with which the reinforcement structure which concerns on Embodiment 1 is equipped over time. 6 is a schematic view showing a part of a reinforcing body provided in a reinforcing structure according to Embodiment 2. FIG. It is the schematic of the bank body of the water storage dam reinforced with the conventional anchor structure.

  Hereinafter, an example in which the reinforcing structure of the concrete structure of the present invention is applied to the reinforcement of a bank of a water storage dam will be described with reference to the drawings.

<Embodiment 1>
As shown in FIGS. 1 and 2, the concrete structure reinforcement structure 1 of the present invention comprises a plurality of concrete structure reinforcement bodies 2 provided in the width direction of the dam body C of the water storage dam (in FIG. Reinforcing bodies 2 are lined up in the direction). Each reinforcing body 2 includes a PC cable 10, a block body 20, and a support block (tension force transmission member) 30, and reinforces the dam body C by applying a compressive force to the dam body C of the water storage dam. To do. Hereinafter, the construction method of the reinforcing structure 1 will be described, and the configuration of each reinforcing body 2 of the reinforcing structure 1 will be described in detail.

  First, when constructing each reinforcing body 2 of the reinforcing structure 1, the holes H <b> 1 and H <b> 2 are formed from the upper end portion of the bank body C toward the ground G. The drilling holes H1 and H2 may be formed vertically downward so that the distance from each other gradually increases toward the ground G, but they are formed vertically downward so as to be parallel to each other. Is preferred. When the drill holes H1 and H2 are formed vertically below, when the PC cable 10 is inserted into the drill holes H1 and H2 and is tensioned as will be described later, the tension force is compressed most efficiently. It can be converted into power to do.

  The drilling holes H1 and H2 may be formed so as to line up in the thickness direction of the levee body C as shown in FIG. 2 (A), or the width of the dam body C as shown in FIG. 2 (B). You may form so that it may rank with a direction. Further, the interval between the hole H1 and the hole H2 is set to be twice or more the minimum bending radius set for the PC cable 10 inserted into the holes H1 and H2. By doing so, as shown in FIG. 1, even if one end 11 of one PC cable 10 is inserted into the hole H1, and the other end 12 is inserted into the other hole H2, the PC cable 10 is damaged by bending. Can be prevented.

  Further, a PC cable 10 is prepared for constructing the reinforcing body 2. In the PC cable 10, for example, a plurality of strands in which a plurality of strands are twisted and integrated with an insulating coating such as epoxy, and a plurality of strands are twisted together and then stored in a polyethylene sheath together with a rust inhibitor such as wax Cables can be used. In addition, as described in Patent Documents 1 to 3, a PC cable or the like in which a single strand or a plurality of strands are housed in a corrugated sheath can be used.

  In addition to the PC cable 10, a block body 20 having a size that can be disposed on the upper end surface of the bank body C is prepared. The block body 20 includes a guide body (curved portion) 21 that bends the PC cable 10 so as to protrude vertically upward. The guide body 21 is a bowl-shaped member produced by halving the bending tube, and is embedded in the upper end surface of the block body 20 so that the inner peripheral surface thereof is exposed from the block body 20. The material of the block body 20 is not particularly limited as long as it has a predetermined strength. For example, concrete can be used. The material of the guide body 21 is not particularly limited as long as it has a predetermined strength and is excellent in corrosion resistance. For example, steel excellent in rigidity and corrosion resistance, polyethylene inexpensive and excellent in corrosion resistance, and the like can be used.

  When the PC cable 10 and the block body 20 are prepared, the jack J is arranged on the upper end surface of the bank body C and the block body 20 is placed on the jack J as shown in FIG.

  Next, the sheaths at both ends of the prepared PC cable 10 are peeled off, the strands of the PC cable 10 are exposed, and the exposed portions are fixed to an unmoving body with grout or the like. In the present embodiment, as shown in FIG. 1, one end 11 of the PC cable 10 is inserted into the hole H1, fixed to the ground G portion in the hole H1, and the other end 12 of the PC cable 10 is fixed to the hole H2. And fixed to the portion of the ground G in the drilling hole H2. When the one end 11 and the other end 12 are fixed, an intermediate portion of the PC cable 10 is disposed on the inner peripheral surface of the guide body 21 and the PC cable 10 is stretched as loosely as possible. By these operations, the middle portion of the PC cable 10 is supported by the guide body 21 and is bent so as to protrude vertically upward.

  When the fixing of both ends of the PC cable 10 is completed, the block body 20 is lifted vertically upward by the jack J as shown by the white arrow in FIG. By doing so, the intermediate part of the PC cable 10 to which both ends are fixed is also lifted vertically upward, and the PC cable 10 is tensioned. The introduction load introduced into the PC cable 10 by tensioning the PC cable 10 is preferably about 60% of the standard tensile load.

  In addition, you may integrate the PC cable 10 which finished tension | tensile_strength with the guide body 21 by grout. Further, after tensioning the PC cable 10, grout or the like may be injected into the holes H1 and H2, and the holes H1 and H2 may be integrated with the PC cable 10 in the holes H1 and H2. In this case, the PC cable 10 cannot be re-tensioned, but the strength of the dam body C can be improved as compared with leaving the drilling holes H1 and H2, and the PC cable 10 in the drilling holes H1 and H2 can be improved. It is also possible to strengthen the rust prevention.

  When the PC cable 10 is tensioned with the jack J and a predetermined load is introduced to the PC cable 10, it can be made of concrete or the like between the block body 20 and the upper end surface of the dam body C as shown in FIG. A plurality of support blocks 30 are interposed. And the jack J is loosened, the jack J is removed from the upper end surface of the bank body C, and the block body 20 is supported only by the support block 30 as shown in FIG. Further, a rust prevention structure may be constructed by covering the entire portion above the bank C from the state of FIG. 3C with a rust prevention cap or the like and filling the cap with a rust prevention agent.

  One reinforcing body 1 shown in FIGS. 1 and 2 can be completed by the series of steps described above. Thereafter, as shown in FIG. 2, the reinforcement structure 1 of the concrete structure including the plurality of reinforcement bodies 2 arranged in parallel in the width direction of the bank body C by repeating the formation of the reinforcement body 1 in the width direction of the bank body C. Build up.

  In each reinforcing body 2 of the completed reinforcing structure 1, as shown in FIG. 1, the block body 20 is pulled down vertically by the tension force introduced into the PC cable 10. The block body 20 compresses the bank body C via the support block 30, and the bank body C is reinforced.

<Modified Embodiment>
In the reinforcing body 2 shown in the first embodiment, a jack J that lifts the block body 20 may be used as a tension transmitting body. In that case, in constructing the reinforcing body 2, the block body 20 is lifted by the jack J as shown in FIG. 3A, and then the jack J is placed on the upper end surface of the dam body C as it is.

  According to the said structure, even if the tension | tensile_strength of the PC cable 10 loosens with the passage of time after construction of the reinforcement body 2, the PC cable 10 can be quickly re-tensioned. Re-tensioning of the PC cable 10 may be performed automatically. In that case, a sensor for monitoring the tension of the PC cable 10 may be provided, and a control mechanism for controlling the jack J based on the detection result of the sensor may be provided.

<Embodiment 2>
A reinforcing body in which the configuration of the bending portion provided in the block body is different from that of the first embodiment described above will be described with reference to FIG.

  FIG. 4 is a schematic view showing a formation state of the reinforcing body 2 ′ of the present embodiment in the vicinity of the upper end surface of the bank body C. As shown in FIG. 4, the block body 20 ′ of the reinforcing body 2 ′ includes a tubular body 22 that bends the PC cable 10 so as to protrude vertically upward, like the guide body shown in the first embodiment. The tube body 22 is embedded in the block body 20 ′ so that both end portions thereof are opened on the side surfaces of the block body 20 ′.

  According to the tubular body 22, the intermediate portion of the PC cable 10 bent into a hairpin shape can be effectively protected. Even if the outer periphery of the PC cable 10 is not damaged at the intermediate portion, a large bending stress is applied. Therefore, the PC cable 10 may be damaged by an external impact. The possibility can be reduced with the tube 22.

  The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, after the reinforcement structure 1 is completed as shown in FIG. 2, all the block bodies 20 of the reinforcement structure 1 may be integrally covered with concrete as indicated by a two-dot chain line in the figure. By doing so, the bulk of the bank body C can be increased, and the upper surface of the bank body C can be flattened to secure a passage for maintenance.

  The reinforcing body and the reinforcing structure of the concrete structure of the present invention can be suitably used for reinforcing a concrete structure such as a dam, a breakwater, and an underground station building that is not easily remodeled.

C Dyke body (concrete structure)
G Ground H, H1, H2 Drilling hole D Fixing tool 1 Reinforcing structure 2, 2 'Reinforcing body 10 PC cable 11 One end 12 Other end 20, 20' Block body 21 Guide body (curved portion) 22 Tube body (curved portion)
30 Support block (tension force transmission body)
J jack

Claims (11)

A concrete structure reinforcement body that reinforces a concrete structure by applying a tension force of a strained PC cable as a compressive force to the concrete structure,
In the concrete structure, two drill holes reaching the ground through the concrete structure from the upper end of the concrete structure are formed,
The reinforcing body is
A PC cable having one end fixed to the ground portion in one of the drilling holes and the other end fixed to the ground portion in the other drilling hole;
A block body that has a curved portion that supports the middle portion of the PC cable so as to protrude vertically upward, and is disposed at an upper end portion of the concrete structure;
The PC cable, which is interposed between the block body and the upper end surface of the concrete structure, maintains the tension of the PC cable supported by the block body, and a part of the tension of the PC cable is applied to the concrete structure. A tension transmitting body that transmits to the upper end surface;
A reinforcing body for a concrete structure, comprising: The bending portion is a curved bowl-shaped guide body through which the PC cable is guided,
The reinforcing body for a concrete structure according to claim 1, wherein the guide body is embedded in the block body so that an inner peripheral surface thereof is exposed at an upper end surface of the block body. The bending portion is a curved tube body through which the PC cable is inserted,
The reinforcing body for a concrete structure according to claim 1, wherein the tubular body is embedded in the block body.   The said PC cable is being fixed to the said curved part by grout, The reinforcement body of the concrete structure as described in any one of Claims 1-3 characterized by the above-mentioned.   The reinforcing member for a concrete structure according to any one of claims 1 to 4, wherein the tension transmitting body is a jack that lifts the block body from an upper end surface of the concrete structure.   The said tension transmission body is a support block interposed between the said block body and the upper end surface of a concrete structure, The concrete structure as described in any one of Claims 1-4 characterized by the above-mentioned. Reinforcing body.   The said PC cable is a multi-cable, The reinforcement body of the concrete structure as described in any one of Claims 1-6 characterized by the above-mentioned.   A reinforcing structure for a concrete structure formed by providing a plurality of reinforcing bodies for a concrete structure according to any one of claims 1 to 7 in one concrete structure. When the concrete structure is a dam,
The reinforcing structure for a concrete structure according to claim 8, wherein a plurality of the reinforcing bodies are juxtaposed in the width direction of the dam. A method of reinforcing a concrete structure for reinforcing a concrete structure by applying a tension force of a strained PC cable as a compressive force to the concrete structure,
Forming two drill holes reaching the ground through the concrete structure from the upper end of the concrete structure;
Placing a jack on the upper end of the concrete structure;
A step of placing a block body having a curved portion that is curved so as to protrude vertically upward on the jack;
A step of arranging an intermediate portion of the PC cable in the curved portion, and fixing one end and the other end of the PC cable to a ground portion in separate drilling holes;
Lifting the block body vertically upward with the jack and tensioning the PC cable with both ends fixed;
With
A method of reinforcing a concrete structure, wherein the block body is pulled down toward the concrete structure with a part of the tension of the PC cable to apply a compressive force to the concrete structure. Furthermore, a step of removing the jack by interposing a support block between the block body lifted vertically upward and the upper end surface of the concrete structure,
The method for reinforcing a concrete structure according to claim 10, wherein a compressive force is applied to the concrete structure through the support block.

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