JP5273663B2 - Anchor structure using anticorrosion PC strand, construction method thereof, and composite anchor member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anchor structure using an anticorrosive prestressed concrete (PC) strand having high durability and achieving excellent workability in construction work and to provide a construction method for this anchor structure. <P>SOLUTION: In this anchor structure A, a plurality of anticorrosive PC strands 2 to be arranged in a drilled hole H formed on a construction face S are fixed in an opening part of the drilled hole H while the strands 2 are tightly stretched to give tension force of each strand 2 onto the construction face S as compressive force. This anticorrosive PC strand 2 is arranged in a corrugated sheath 4, and a region in the corrugated sheath between the anticorrosive PC strand 2 and the corrugated sheath 4 is divided into a region 1 and a region 2 by a partitioning member 5. Primary grout 10, a delayed hardening resin 20 (an anticorrosive material), and secondary grout are arranged in the region 1, the region 2, and a region 3 between the drilled hole H and the corrugated sheath 4, respectively. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an anchor structure using an anticorrosion PC strand for improving the durability of an existing concrete structure, a construction method thereof, an anticorrosion PC strand assembly used for the anchor structure, and a composite anchor member. . In particular, the present invention relates to an anchor structure for reinforcing a concrete structure that is difficult to reconstruct, such as a dam, a breakwater, and an underground station building, a method for constructing the anchor structure, an anticorrosion PC strand assembly, and a composite anchor member. is there.

  Conventionally, an anchor structure for reinforcing a slope of a retaining wall is known (for example, see Patent Document 1). This anchor structure is configured by fixing a plurality of anticorrosion PC strands arranged in a drilling hole formed on the slope of the retaining wall, which is a construction surface, to the opening of the drilling hole in a tensioned state. And this anchor structure reinforces a retaining wall by providing the tension | tensile_strength of each anticorrosion PC strand as a compressive force to a construction surface.

  FIG. 3 is a diagram illustrating an example of an anchor structure. A method for forming such an anchor structure will be described below.

  In order to form the anchor structure B, first, a plurality of anticorrosion PC strands 110 are arranged in the hole H formed from the concrete construction surface S covering the surface of the ground G toward the ground G. Each strand 110 is accommodated in one sheath 130 while being separated from each other by a spacer 120. When the strand 110 is arranged in the hole H, one end of the sheath 130 is peeled off by a predetermined length, and the strand 110 is exposed at that portion. At the end of the peeled sheath 130, a water stop portion 140 that seals the gap between the sheath 130 and the strand 110 is formed.

  Next, the end of the anticorrosion PC strand 110 exposed to the outside from the hole H is temporarily fixed to the ground G with the anchor disk D and the anchor plate P, and the hole H is sealed. When the arrangement of the strand 110, the anchor disk D, and the anchor plate P is completed, the grout is injected into the hole H. When a predetermined time has elapsed from filling of the grout H to the grout, the grout is cured. Here, the illustrated strand 110 has an exposed portion (fixing length portion) and a portion covered by the sheath 130 (free length portion) with the water stop portion 140 sealing the opening portion of the sheath 13 as a boundary. It is divided. Therefore, only the exposed portion of the strand 110 is fixed to the hole H when the grout is cured.

  Finally, the strand 110 protruding from the anchor disk D is tensioned and fixed to the anchor disk D with the wedge W, thereby completing the anchor structure B. The tension applied to the strand 110 is transmitted to the construction surface S via the wedge W, the anchor disk D, and the anchor plate P.

Japanese Patent Laid-Open No. 5-125656

  In recent years, based on the lessons learned from the Great Hanshin-Awaji Earthquake, anchor structures have been applied to concrete structures that cannot be easily remodeled, such as existing dams, breakwaters, and underground station buildings. It is recommended to do. When an anchor structure is applied to such a concrete structure, a required characteristic is to have long-term reliability, that is, durability. However, if the conventional anchor structure such as Patent Document 1 described above is applied to the reinforcement of a concrete structure such as a dam as it is, the durability of the anchor structure may not be sufficient.

  As shown in FIG. 3, the exposed portion (fixed length portion) of the strand 110 is only covered by the grout, so that it is completely waterproof against water that oozes out from the ground G into the hole H. It is hard to say that measures are being taken. When the strands 110 are rusted, the durability of the anchor structure B is lowered. Therefore, it is important to take a waterproof measure against the bare strands 110. In particular, in the anchor structure B provided in a concrete structure such as a dam or a breakwater in an environment where a large amount of water exists, it is expected that the importance of waterproofing measures is high.

  Further, when the hole H is formed in the concrete structure, since the inner peripheral surface of the hole H is hard, the exposed strand 110 may come into contact with the inner peripheral surface of the hole H to be damaged. Therefore, it is necessary to carefully insert the strand 110 into the hole H, and workability when constructing the anchor structure B is not good.

  The present invention has been made in view of the above circumstances, and one of its purposes is an anchor structure using an anticorrosion PC strand having high durability and excellent workability during construction, and a method for constructing this anchor structure. It is to provide. Another object of the present invention is to provide an anticorrosion PC strand assembly suitable for the construction of the anchor structure, and a composite anchor member.

<Anchor structure>
The present invention applies the tension of the anticorrosion PC strand as a compressive force to the construction surface by fixing the anticorrosion PC strand placed in the drilling hole formed on the construction surface in a tensioned state at the opening of the drilling hole. The present invention relates to an anchor structure using an anticorrosion PC strand. The anticorrosion PC strand provided in the anchor structure is a resin-coated PC strand. And the anchor structure of this invention is a corrosion prevention PC strand by partitioning the corrugated sheath in the corrugated sheath between the corrosion prevention PC strand and the corrugated sheath in the longitudinal direction of the corrosion prevention PC strand. A partition member that divides the hole into a free length portion on the opening side of the drilling hole and a fixing length portion on the back side of the drilling hole, and a primary grout filled in the rear side of the drilling hole with the partitioning member sandwiched in the corrugated sheath inner region And a secondary grout filled between the drilling hole and the corrugated sheath, and an anticorrosive material filled on the construction surface side with the partition member sandwiched in the corrugated sheath inner region.

  By setting it as the structure of this invention, since the whole anticorrosion PC strand in a drilling hole is covered with the corrugated sheath and it is not in the state of being exposed, the PC strand of an anticorrosion PC strand is very hard to corrode. Moreover, since the anticorrosion PC strand in the anchor structure of the present invention is in a state protected by the corrugated sheath during the construction work of the anchor structure, it is arranged in a state with almost no damage. Therefore, the anchor structure of the present invention has very high durability, and can continuously apply a predetermined tension force to the construction surface over a long period of time.

  Further, according to the anchor structure of the present invention, the inner diameter of the drilling hole can be reduced even when the same number of anticorrosion PC strands are arranged as compared with the conventional anchor structure. In the conventional anchor structure, the interval between the anticorrosion PC strands arranged in one sheath must be a predetermined value or more, and since the sheath receives the tension of all the anticorrosion PC strands, A predetermined interval is also required between the inner peripheral surface. On the other hand, in the anchor structure of the present invention, since one anticorrosion PC strand is accommodated in one corrugated sheath, the tension force received by one sheath is smaller than the conventional one. Therefore, although the intervals between the plurality of corrugated sheaths arranged in the hole must be set to a predetermined value or more, the sheaths can be arranged relatively densely. As a result, if the anchor structure of the present invention is compared with the conventional anchor structure, the anchor structure of the present invention can be formed with smaller drilling holes.

<Anti-corrosion PC strand assembly>
The anticorrosion PC strand assembly of the present invention includes an anticorrosion PC strand composed of a resin-coated PC strand, a corrugated sheath that accommodates the anticorrosion PC strand therein, and an area in the corrugated sheath between the anticorrosion PC strand and the corrugated sheath Is provided with a partition member that partitions the anticorrosion PC strand into a fixing length portion and a free length portion. Furthermore, the anticorrosion PC strand of the present invention is filled in the corrugated sheath inner region with a hardened primary grout filled on one side with the partition member in between and the corrugated sheath inner region on the other side with the partition member in between. An anticorrosive material.

  According to the anticorrosion PC strand assembly of the present invention, since the entire anticorrosion PC strand is covered with the corrugated sheath, the anticorrosion PC strand is hardly damaged when the anticorrosion PC strand is inserted into the hole. Further, in the state where the anticorrosion PC strand is arranged in the drilling hole, the PC strand is protected by the triple anticorrosion structure of the resin coating, the corrugated sheath, and the filler (primary grout or anticorrosive material) in the sheath. . Therefore, the anchor structure formed using the anticorrosion PC strand assembly of the present invention has very high durability and can continue to impart a predetermined tension to the construction surface over a long period of time.

  In the anticorrosion PC strand assembly of the present invention, the corrugated sheath is preferably formed of a transparent resin.

  According to this configuration, it is possible to confirm the filling state of the grout and the anticorrosive material inside the sheath from the outside of the corrugated sheath. Therefore, an anchor structure is not constructed using an anticorrosion PC strand assembly that is not sufficiently filled with primary grout or anticorrosion material.

  In the anticorrosion PC strand assembly of the present invention, the anticorrosion material may be a delayed curing resin.

  When the anchor structure is constructed using the anticorrosion PC strand assembly, the anticorrosion PC strand in a tensioned state is fixed over almost the entire length. Therefore, the tension of the anticorrosion PC strand is difficult to loosen over a long period of time.

  In the anticorrosion PC strand assembly of the present invention, the anticorrosion material may be a rust inhibitor that does not harden over time.

  When the anchor structure is constructed using the anticorrosion PC strand assembly, the anticorrosion PC strand is not restrained by the rust preventive agent, so that the anticorrosion PC strand can be re-tensioned. Therefore, if the anticorrosion PC strand is re-tensioned every predetermined period, a predetermined tension can be applied to the construction surface over a long period of time.

<Composite anchor member>
The anticorrosion PC strand assembly of the present invention described above can be handled as a composite anchor member in which a plurality of anticorrosive PC strand assemblies are combined into one. That is, the composite anchor member of the present invention includes a plurality of the anticorrosion PC strand assemblies of the present invention and spacers that hold the anticorrosion PC strand assemblies in a separated state.

  By using a composite anchor member, a predetermined number of anticorrosion PC strand assemblies can be collectively arranged in the drilling hole. Therefore, an anchor structure can be constructed easily and in a short time.

<Construction method of anchor structure>
Moreover, the anchor structure for reinforcing the said structure by giving compressive force to a concrete structure using the corrosion-proof PC strand assembly | attachment body of this invention can be constructed | assembled. That is, the present invention is a method of constructing an anchor structure for reinforcing a concrete structure by applying prestress to a concrete structure installed on the ground, and includes the following steps.
-The process of inserting the anticorrosion PC strand assembly of this invention in the drilling hole formed in the construction surface of the concrete structure.
-The process of filling the secondary grout into the drilling hole.
A process of tensioning and fixing the anticorrosion PC strand after the secondary grout is cured.

  According to the anchor structure construction method of the present invention, an anchor structure having a predetermined durability can be constructed. In particular, in the anticorrosion PC strand assembly of the present invention used in this method, the anticorrosion PC strand is protected by a corrugated sheath, and excessive cautiousness is not required when inserting the anticorrosion PC strand into the drilling hole. For this reason, the anchor structure construction method of the present invention is superior to the conventional method in terms of workability.

  Moreover, in the construction method of the anchor structure of the present invention, when a plurality of anticorrosion PC strand assemblies to be inserted into the drilling holes are used, it is preferable to insert them in the state of a composite anchor member. In this way, since the required number of anticorrosion PC strand assemblies can be inserted into the drilling holes at once, an anchor structure can be constructed with good workability.

  The anchor structure of the present invention has very high durability, and can continue to impart a predetermined tension to the construction surface over a long period of time. Therefore, according to the anchor structure of the present invention, it is possible to reinforce a concrete structure that is difficult to be reconstructed, such as a dam, a breakwater, and an underground station building, and maintain the concrete structure over a long period of time.

The schematic which applied the anchor structure of this invention to the dam body (concrete structure) of a dam is shown. It is a schematic block diagram which shows the main part of an anchor structure. It is the schematic of the conventional anchor structure.

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

  FIG. 1 is a schematic view in which the anchor structure of the present invention is applied to a dam body C (concrete structure). FIG. 2 is a schematic configuration diagram showing main parts of the anchor structure.

  First, the hole H is formed in the dam body C (see FIG. 1). The drilling hole H penetrates the dam body C and reaches the ground G at a position deeper than the dam body C.

  Next, the anticorrosion PC strand assembly 1 of the present invention is prepared (see FIG. 2). The anticorrosion PC strand assembly 1 includes a corrugated sheath 4 and a single anticorrosive PC strand 2 disposed in the corrugated sheath 4. For example, the corrugated sheath 4 may be formed of a transparent resin such as polyethylene for the purpose of confirming a filling state of a substance (described later) filled in the corrugated sheath 4, or for the purpose of ensuring strength. For example, you may form with metals, such as stainless steel. Moreover, the anticorrosion PC strand 2 has the resin coating 3 on the surface as a countermeasure against corrosion. An example of the resin coating 3 is an epoxy resin.

  In the corrugated sheath 4 of the anticorrosive PC strand assembly 1, a region formed between the anticorrosive PC strand 2 and the corrugated sheath 4 is divided into two regions R1 and R2, and a liquid is formed between both regions. A partition member 5 (for example, elastic rubber, sponge, cured resin, or the like) that regulates body movement is provided. An already hardened grout 10 is arranged in this region R 1, and the anticorrosion PC strand 2 is fixed to the corrugated sheath 4. On the other hand, the region R2 is filled with a delayed curing resin 20, and is cured within several years after the anchor structure is constructed. The partition member 5 is usually provided so as to be at the position of the ground G below the levee body C when the anticorrosion PC strand assembly 1 is disposed in the hole H.

  The partition member 5 can be formed as follows, for example. First, a sponge or elastic rubber is previously attached to the partition member attachment position of the anticorrosion PC strand 2, and a delayed curing resin such as two-component foamed urethane is applied to the part. Then, the corrugated sheath 4 is put on the outer periphery of the strand 2 before the resin is cured, and the partition member 5 is formed by curing the resin. Such a partition member 5 should just have sealing force of the grade which the primary grout with which area | region R1 was filled does not leak.

  When inserting the anti-corrosion PC strand assembly 1 into the drilling hole H, a composite anchor member in which a plurality of anti-corrosion PC strand assembly 1 is combined into one is made, and this composite anchor member is inserted into the drilling hole H. To do. Here, depending on the position of the partition member 5 in the above-described anticorrosion PC strand assembly 1, the region R <b> 1 in the cable 1 inserted into the hole H is disposed at a position completely surrounded by the ground G. By setting the region R1 in this manner, prestress can be applied to the dam body C when the anticorrosion PC strand 2 of the anticorrosion PC strand assembly 1 is tensioned and fixed.

  The composite anchor member is formed by preparing a plurality of anticorrosion PC strand assemblies 1 and holding each assembly 1 in a separated state by spacers 6. The spacer 6 may be a plate-like member having a plurality of through holes, for example. In this case, after inserting the assembly 1 into each through hole, the assembly 1 and the spacer 6 are integrated together by filling a gap between the through hole and the assembly 1 with resin or the like. It ’s fine. The composite anchor member may be assembled at the construction site, or assembled at the factory and brought into the site.

  After the composite anchor member is disposed in the hole H, the anchor plate P is disposed so as to contact the construction surface S, and the joint pipe J and the anchor disk D are sequentially disposed on the plate P.

  The joint pipe J includes a bottomed pipe part and a flange part extending in the radial direction of the pipe part on the opening side of the pipe part, and one anticorrosion PC strand assembly 1 can be inserted into the bottom of the pipe part one by one. It has a through hole. The anchor plate P is a flat plate-like member, and has a through hole through which the pipe portion of the joint pipe J can be inserted. The anchor disk D has a through hole through which the assembly 1 can be inserted one by one at a position corresponding to the through hole of the joint pipe J.

  If the joint pipe J is arranged on the anchor plate P, the pipe portion of the joint pipe J penetrates through the through hole of the anchor plate P and is arranged in the drilling hole H, and at the through hole of the pipe portion of the joint pipe J The assembly 1 is inserted. And the area | region R3 between the drilling hole H and a composite anchor member is formed by the pipe | tube part bottom face of the joint pipe J by sealing the clearance gap between the through-hole of the joint pipe J and the assembly body 1. FIG.

  Further, if the anchor disk D is arranged on the flange portion of the joint pipe J, the anticorrosion PC strand 2 is arranged in a state of protruding from the through hole of the disk D, and a region R4 is formed in the pipe section of the joint pipe J. .

  Next, cement-based secondary grout is injected into the region R3 in a state where the above-described members P, J, and D are arranged. The injection of the secondary grout may be performed by a communication pipe (for example, a hose penetrating the members D and J) communicating with the region R3 from the outside.

  When the secondary grout injected into the region R3 is cured, the anticorrosion PC strand 2 of the anticorrosion PC strand assembly 1 is tensioned. Here, the strand 2 is fixed to the corrugated sheath 4 by the primary grout 10, and the corrugated sheath 4 is fixed to the hole H by the secondary grout. Therefore, even if the strand 2 is tensioned, the strand 2 in the region R1 functions as a fixing length portion that keeps its position without substantially extending. On the other hand, since the strand 2 in the region R2 is surrounded by the delayed curing resin 20 and is not fixed to the corrugated sheath 4, the strand 2 functions as a free length portion that can be extended. In this state, the strand 2 is fixed to the anchor disk D by the wedge W while the anticorrosion PC strand 2 is tensioned. The fixed strand 2 applies a compressive force to the construction surface S (that is, the bank body C) via the wedge W, the anchor disk D, the joint pipe J, and the anchor plate P.

  Finally, the tertiary grout is filled into the region R4 from the grout filling hole provided in the anchor disk D to complete the anchor structure. The anchor structure A thus completed has high corrosion resistance because there is no portion where the anticorrosion PC strand 2 is exposed in the hole H. That is, the strand 2 is maintained in a healthy state over a long period of time, and a predetermined tension can be continuously applied to the dam body C. Further, in the anchor structure A of the present embodiment, the strand 2 is constrained by curing the delayed curing resin 20 in the region R2 several years after the construction, so that the tension introduced into the strand 2 is not easily loosened.

  In addition, this invention is not necessarily limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably. For example, when the anticorrosive material filled in the region R2 is a rust preventive agent (such as grease) that does not cure over time, the anticorrosion PC strand 2 can be an anchor structure A that can be re-tensioned.

  INDUSTRIAL APPLICABILITY The anchor structure and its construction method, the anticorrosion PC strand assembly, and the composite anchor member can be suitably used for reinforcing concrete structures that are not easily remodeled, such as dams, breakwaters, and underground station buildings.

C Dam body (concrete structure) G Ground S Construction surface H Drill hole W Wedge D Anchor disk J Joint pipe P Anchor plate A Anchor structure 1 Corrosion-proof PC strand assembly 2 Corrosion-proof PC strand 3 Resin coating 4 Corrugated sheath 5 Partition member 6 Spacer 10 Primary grout 20 Delay curing resin (corrosion protection material)
R1 to R4 region B anchor structure 110 anticorrosion PC strand 120 spacer 130 sheath 140 waterstop

Claims (3)

By fixing a plurality of anticorrosion PC strands arranged in the drilling hole formed on the construction surface to the opening of the drilling hole in a tensioned state, the tension of the anticorrosion PC strand is applied to the construction surface as a compressive force. An anchor structure using an anticorrosion PC strand for
The anticorrosion PC strand is a resin-coated PC strand,
A corrugated sheath for individually storing each anticorrosion PC strand one by one,
By partitioning the area inside the corrugated sheath between the anticorrosive PC strand and the corrugated sheath in the longitudinal direction of the anticorrosive PC strand, the anticorrosive PC strand is divided into a free length portion on the opening side of the drilling hole and a fixing length portion on the back side of the drilling hole. A partition member that divides into
A primary grout filled in the back side of the drilling hole across the partition member in the corrugated sheath inner region;
A secondary grout filled between the drilling hole and the corrugated sheath;
An anticorrosive material filled on the construction surface side across the partition member in the area inside the corrugated sheath, and
An anchor structure using an anticorrosion PC strand, comprising: A plurality of anticorrosive PC strand assemblies having the following configuration ;
A composite anchor member comprising a spacer for holding each anticorrosion PC strand assembly in a separated state.
The anti-corrosion PC strand assembly is
An anticorrosion PC strand comprising a resin-coated PC strand;
A corrugated sheath that houses a single anticorrosion PC strand;
A partition member that divides the anticorrosion PC strand into a fixing length portion and a free length portion by partitioning a region in the corrugated sheath between the anticorrosion PC strand and the corrugated sheath in the longitudinal direction of the anticorrosion PC strand;
Of the corrugated sheath region, a hardened primary grout filled on one side with the partition member in between;
Of the corrugated sheath region, the anticorrosive material filled in the other across the partition member,
Is provided. A method for constructing an anchor structure for reinforcing a concrete structure by applying prestress to a concrete structure installed on the ground,
Corrosion PC strand assembly body having the following configuration and a step of inserting a drilling formed on the construction surface of the concrete structure,
Filling a secondary grout into the drilling hole;
After the secondary grout is cured, a step of tensioning and fixing the anticorrosion PC strand;
An anchor structure construction method characterized by comprising:
The anti-corrosion PC strand assembly is
An anticorrosion PC strand comprising a resin-coated PC strand;
A corrugated sheath that houses a single anticorrosion PC strand;
A partition member that divides the anticorrosion PC strand into a fixing length portion and a free length portion by partitioning a region in the corrugated sheath between the anticorrosion PC strand and the corrugated sheath in the longitudinal direction of the anticorrosion PC strand;
Of the corrugated sheath region, a hardened primary grout filled on one side with the partition member in between;
Of the corrugated sheath region, the anticorrosive material filled in the other across the partition member,
Is provided.

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