JP5476654B2 - Reinforcing body for concrete structure, reinforcing structure for concrete structure, and method for reinforcing concrete structure - Google Patents

Description

  The present invention relates to a method for reinforcing a concrete structure that reinforces a concrete structure that is difficult to be reconstructed with a PC cable, such as a dam or an underground station building, a reinforcing body for a concrete structure constructed by the reinforcing method, and the reinforcing body It is related with the reinforcement structure of the concrete structure provided with two or more.

  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 levee body C by 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 order to reinforce a concrete structure with the anchor structure described above, it is necessary to form a hole in the concrete structure, and when the hole is formed, the durability of the concrete structure is reduced. There is concern about it.

  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 reinforce a concrete structure that is difficult to remodel without forming a hole in the concrete structure, Another object of the present invention is to provide a reinforcing structure for a concrete structure including a plurality of reinforcing bodies. Another object of the present invention is to provide a method for reinforcing a concrete structure for reinforcing the concrete structure without forming a drilling hole.

  The reinforcing body of a concrete structure of the present invention is a reinforcing body of a concrete structure that reinforces a concrete structure by applying a tension force of a tensioned PC cable as a compressive force to the concrete structure, and includes a PC cable, A block body and a tension transmission body are provided. One end of the PC cable is fixed to a non-moving body different from the concrete structure, and the other end is fixed to another non-moving body on the opposite side of the non-moving body with the concrete structure interposed therebetween. 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 force transmitting 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 one of the tension forces of the PC cable. It is a member which transmits a part to the upper end surface of a concrete structure.

  According to the reinforcing body of a concrete structure of the present invention, the concrete structure can be reinforced without making a hole in the concrete structure.

  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 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.

  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.

  By the way, in the reinforcing body of the present invention, most of the PC cable is exposed to the outside. On the other hand, a multi-cable having a sheath on the outermost periphery is not easily damaged even when exposed to the external environment. Therefore, if the reinforcing body includes a multi-cable, a compressive force can be applied to the concrete structure over a long period of time. .

  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.
・ 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 separate non-moving bodies at positions sandwiching the concrete structure.
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 making a hole in the concrete structure.

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

  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 making a hole in the concrete structure portion.

It is the schematic of the sabo 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 bank body of the sabo dam shown in 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 sabo 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 sabo dam body 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 sabo dam. 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 transmitting member) 30, and reinforces the dam body C by applying a compressive force to the dam body C of the sabo 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, in constructing each reinforcing body 2 of the reinforcing structure 1, the PC cable 10 is prepared. 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 preventive agent 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 constructing the reinforcing body 2, a block body 20 having a size that can be arranged on the upper end surface of the bank body C is prepared in addition to the PC cable 10. A curved tube body (curved portion) 21 is embedded in the block body 20. Both end portions of the tube body 21 are open to the side surface of the block body 20 so that the PC cable 10 can be inserted into the tube body 21. 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 tube 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. Further, the PC cable 10 is inserted into the tube body 21 of the block body 20. The intermediate portion of the PC cable 10 inserted through the tube body 21 is supported by the tube body 21 and is curved so as to protrude vertically upward.

  Next, the sheaths at both ends of the PC cable 10 are peeled off, the strands of the PC cable 10 are exposed, and the exposed portions are fixed to a non-moving body with a grout or the like. In the present embodiment, as shown in FIG. 1, one end 11 of the PC cable 10 is fixed to a portion of the ground G located at a position lower than the block body 20 on the left side of the dam body C, and the PC cable 10 The other end 12 is fixed to a portion of the ground G that is on the right side of the paper surface from the dam body C. When the one end 11 and the other end 12 are fixed, the PC cable 10 is stretched as loosely as possible. In addition, when fixing the other end 12 that is submerged in the drawing, the water in the vicinity thereof is drained.

  Here, the position where the one end 11 and the other end 12 of the PC cable 10 are fixed is preferably a position close to the dam body C. For example, when the inclination of the PC cable 10 with respect to the horizontal plane perpendicular to the direction of gravity is θ, θ is preferably 45 ° or more, and more preferably 60 ° or more (less than 90 °). The larger the θ is, the shorter the total length of the PC cable 10 can be. Moreover, since the vertical component of the tension force of the PC cable 10 increases as θ increases, the compressive force that can be applied to the dam body C by the single PC cable 10 can be increased.

  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.

  The tensioned PC cable 10 may be integrated with the tube body 21 by grouting. In that case, the gap between the open end of the tube body 21 and the PC cable 10 may be sealed with a known water stop structure such as a rubber boot described in FIG. 1 of JP-A-2007-309028, for example.

  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 vertically downward component of 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 guide body 22 that bends the PC cable 10 so as to protrude vertically upward, like the tube body shown in the first embodiment. The guide body 22 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 ′. .

  According to the guide body 22, when the PC cable 10 is disposed on the guide body 22, the PC cable 10 can be disposed so as to be hooked from above the guide body 22, so that the reinforcement body 2 ′ can be easily formed. become. Here, the PC cable 10 arranged on the guide body 22 may be integrated with the guide body 22 by grout or the like.

  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 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 Tubular body (curved portion) 22 Guide 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,
A PC cable having one end fixed to a non-moving body different from the concrete structure and the other end fixed to another non-moving body on the opposite side of the non-moving body with the concrete structure interposed therebetween;
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 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 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 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,
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 fixing an intermediate portion of the PC cable to the curved portion, and fixing one end and the other end of the PC cable to separate non-moving bodies in a position sandwiching a concrete structure;
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 tension force transmitting body is interposed between the block body lifted vertically upward and the upper end surface of the concrete structure, and the step of removing the jack is provided.
The method for reinforcing a concrete structure according to claim 10, wherein a compressive force is applied to the concrete structure through the tension transmission body.

Images