JP7031970B2 - How to repair PC structures - Google Patents

Description

The present invention relates to a method for repairing a PC structure formed by introducing prestress into concrete by a tension material.

The PC structure formed by introducing prestress into concrete by the tension material is concerned about deterioration of concrete due to aging due to the passage of time and repeated load due to the passage of vehicles and the like. When concrete deteriorates in a normal RC structure, it is repaired by scraping the concrete at the repaired part and then placing new concrete in the scraped part. However, when concrete deteriorates in a PC structure, various repair methods have been proposed, but the present situation has not yet been established. In addition, in the case of a PC structure, if the deteriorated concrete is scraped, the prestress borne by the deteriorated concrete will be borne by other undamaged concrete, reinforcing bars, etc. at the beginning of the design. Since an excessive stress acts on the PC structure, buckling of the PC structure may occur.

Conventionally, as a technique for repairing a PC structure, a method for repairing a PC structure disclosed in Patent Document 1 and a fixing device for a PC tension material disclosed in Patent Document 2 have been proposed.

In the method of repairing a PC structure disclosed in Patent Document 1, concrete is scraped to expose a tension material passing through a portion to be repaired, an intermediate fixing tool is attached to the exposed tension material, and an intermediate fixing tool is used to end the PC structure. The concrete is further removed up to the part, and new concrete is placed on the deleted concrete. However, in the method for repairing a PC structure disclosed in Patent Document 1, not only the damaged part but also the concrete is removed from the intermediate fixing tool to the end portion of the PC structure, so that the area for cutting the concrete is widened. As a result, there was a problem that it took a long time to construct.

The fixing device for the PC tension material disclosed in Patent Document 2 is made of PC steel by inserting two wedge members each having a slit between the PC steel stranded wire and the inner circumference of the truncated cone-shaped tapered hole. The line is fixed in the middle. However, in the PC tensioning material fixing device disclosed in Patent Document 2, it is necessary to remove the PC steel stranded wire to the last when repairing the PC structure, so that it takes time to remove the PC steel stranded wire. There was a point.

Japanese Unexamined Patent Publication No. 2015-086534 Japanese Unexamined Patent Publication No. 2011-184894

Therefore, the present invention has been devised in view of the above-mentioned problems, and an object thereof is to prevent buckling of the PC structure when repairing the PC structure, and the construction period. It is an object of the present invention to provide a repair method of a PC structure which can shorten the time.

The method for repairing a PC structure according to the first invention is a method for repairing a PC structure formed by introducing prestress into concrete by a tension material, and a reinforcing member extended in the longitudinal direction of the tension material is used. The installation process of installing across the repair target area, which is the area from one end to the other end in the direction parallel to the longitudinal direction of the tension material in the repair target part to be repaired, and the concrete scraping in the repair target part. , A repair process in which new concrete is placed in place of the scraped concrete to repair the repair target portion, and a removal in which the reinforcing member is removed after the new concrete placed in the repair step is hardened. Each of the above-mentioned protrusions arranged on both sides of the repair target area by using the above-mentioned PC structure having a protrusion portion which is previously provided with a protrusion in a direction orthogonal to the material axis. It is characterized in that the reinforcing member is erected between the portions .

The method for repairing a PC structure according to the second invention is characterized in that, in the first invention, the reinforcing member is installed facing the surface different from the surface on which the repair target portion is formed in the installation step. And.

The method for repairing a PC structure according to a third aspect of the invention is that, in the first invention or the second invention , the PC structure is a box girder having a space formed inside, and in the installation step, the PC structure is a box girder. It is characterized in that the reinforcing member is arranged in an internal space.

The method for repairing a PC structure according to a fourth aspect of the present invention is the surface in which the repair target portion is formed and the surface on which the repair target portion is formed in the installation step in any one of the first invention to the third invention. It is characterized in that the reinforcing member is installed so as to face the back surface of the above.

The method for repairing a PC structure according to a fifth aspect of the present invention is the method for repairing a PC structure according to any one of the first to fourth inventions, in which in the installation step, a pressing force is applied toward the outside in the longitudinal direction of the reinforcing member. It is characterized in that the reinforcing member is installed.

According to the present invention, by providing an installation process in which a reinforcing member extended in the longitudinal direction of the tension material is installed across the repair target area, the reinforcing member installed in the installation process is in a state of bearing a compressive force. , It is possible to repair the part to be repaired by placing new concrete in place of the scraped concrete. Therefore, according to the present invention, it is possible to prevent buckling of the PC structure when repairing the PC structure.

Further, according to the present invention, in the repair process, it is only necessary to scrape the damaged repair target portion, and the concrete is cut down to the end portion of the PC structure as is performed by the conventional method for repairing the PC structure. Since it is not necessary to do so, it is possible to shorten the construction period by shortening the time for the concrete scraping work.

It is a perspective view of the PC structure used in the repair method of the PC structure to which this invention is applied. FIG. 3 is an enlarged perspective view showing a repair target portion in the PC structure of FIG. 1. In (a), in the method of repairing a PC structure to which the present invention is applied, a PC structure in which a reinforcing member is erected on each of the projecting portions previously projected on both sides in the material axial direction across the repair target area is provided. It is a side view which shows, and (b) is the 3A-3A'cross-sectional view of (a). (A) is a side view showing a PC structure in which a reinforcing member is erected on each fixing member attached to both sides in the material axial direction across the repair target area in the method for repairing a PC structure to which the present invention is applied. Yes, (b) is a 4A-4A'cross-sectional view of (a). (A) is a side view showing a PC structure in which a reinforcing member is erected on a projecting part and a fixing member in the method of repairing a PC structure to which this invention is applied, and (b) is 5A of (a). -5A'is a cross-sectional view, and (c) is a 5B-5B'cross-sectional view of (a). (A) is a cross-sectional view showing a PC structure provided with a tension material having a lumber orthogonal direction Y as a longitudinal direction in a method for repairing a PC structure to which the present invention is applied, and (b) is a cross-sectional view thereof. It is a top view of the PC structure. It is a perspective view which shows the PC structure which used the box girder in the repair method of the PC structure to which this invention was applied. In the method of repairing a PC structure to which the present invention is applied, the PC structure as a box girder in which a reinforcing member is erected on each of the projecting portions previously projected on both sides in the material axial direction across the repair target area is shown. It is a side sectional view, and (b) is the 8A-8A'cross-sectional view of (a). (A) is a side sectional view showing a PC structure as a box girder in which a reinforcing member is erected on each of the projecting portions that are projected in advance in the method for repairing the PC structure to which the present invention is applied. b) is a side sectional view showing a PC structure as a box girder in which a reinforcing member is erected on each fixing member in the method for repairing a PC structure to which the present invention is applied. It is a side sectional view which shows the PC structure provided with the tension material as an outer cable in the repair method of the PC structure to which this invention was applied.

Hereinafter, a mode for carrying out a method for repairing a PC structure to which the present invention is applied will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a PC structure 1 used in a method for repairing a PC structure to which the present invention is applied. FIG. 2 is an enlarged perspective view showing a repair target portion 2 in the PC structure 1 of FIG. 1.

The method for repairing a PC structure to which the present invention is applied is applied to a PC structure 1 formed by introducing prestress into concrete by a tension material 8.

As shown in FIG. 1, the PC structure 1 is a girder material made of concrete having a substantially T-shaped cross section, and a tension material 8 extended in the material axial direction X as a longitudinal direction is arranged inside the concrete. There is. The PC structure 1 is used in a bridge or the like, and a plurality of PC structures 1 are arranged in a direction Y orthogonal to the material axis and placed on a bridge lower structure such as a pier or an abutment (not shown). Here, the longitudinal direction of the PC structure 1 is defined as the material axis direction X, the direction horizontally intersecting the material axis direction X is defined as the material axis orthogonal direction Y, and the direction vertically intersecting the material axis orthogonal direction Y is defined as the height direction Z. do. The PC structure 1 is not limited to the girder material, and may be formed by introducing prestress into concrete by a tension material, and may be, for example, a PC floor slab.

The PC structure 1 is manufactured in a factory or the like, and prestress is introduced into concrete. In the PC structure 1, the prestress to be introduced may be introduced by a prestressed method or may be introduced by a post tension method. In the PC structure 1, prestress is introduced in the material axial direction X by the tension material 8.

The PC structure 1 is provided with concrete projecting portions 9 projecting in advance in the lumber axis orthogonal direction Y at both end portions 1a and 1b and the intermediate portion 1c in the lumber axis direction X. The projecting portion 9 is a so-called cross girder, and concrete is placed between a plurality of PC structures 1 adjacent to each other in the material axis orthogonal direction Y, so that a plurality of adjacent PC structures 1 are adjacent to each other in the material axis orthogonal direction Y. The PC structures 1 of the above are connected to each other.

If the PC structure 1 is damaged due to aging due to the passage of time, repeated load due to the passage of vehicles, etc., the damaged part is removed as the repair target part 2 to be actually repaired, and a new one is used. It is necessary to cast and repair concrete.

The PC structure 1 according to the present embodiment describes a case where the repair target portion 2 is formed on the bottom surface 11, but in the PC structure according to the present invention, the repair target portion 2 is formed on the upper surface 12, the side surface 13, and the like. It may be something that is done.

The PC structure 1 has a repair target area 20 which is an area from one end 2a to the other end 2b in the material axial direction X horizontally parallel to the longitudinal direction of the tension material 8 in the repair target portion 2. That is, the repair target area 20 includes a virtual line 20a cut vertically with respect to the material axis direction X so as to include one end portion 2a of the material axis direction X of the repair target portion 2, and the material axis direction of the repair target portion 2. It is an area between the virtual line 20b cut vertically with respect to the material axis direction X so as to include the other end 2b of X.

Next, a method of repairing the PC structure to which the present invention is applied will be described.

FIG. 3A shows, in the method of repairing a PC structure to which the present invention is applied, a reinforcing member is provided on each of the projecting portions 9 and 9 which are preliminarily projected on both sides of the material axial direction X across the repair target area 20. 3 is a side view showing a PC structure 1 in which 3 is erected, and FIG. 3 (b) is a cross-sectional view taken along the line 3A-3A'of FIG. 3 (a).

The repair method of the PC structure to which the present invention is applied includes an installation step of installing a reinforcing member 3 extended in the material axial direction X horizontally parallel to the longitudinal direction of the tension material 8 across the repair target area 20. After the repair process of scraping the concrete in the repair target part 2 and placing new concrete in place of the scraped concrete to repair the repair target part 2, and after the new concrete cast by the repair process has hardened, It is provided with a removal step of removing the reinforcing member 3.

The reinforcing member 3 is configured to be expandable and contractible in the material axial direction X of the PC structure 1. The reinforcing member 3 has a jack 31 configured to be expandable and contractible, and a rod-shaped member 32 attached to the jack 31. The rod-shaped member 32 has a longitudinal direction extending in the material axial direction X, and a synthetic member made of steel, concrete, steel, concrete, or the like is used.

In the present embodiment, the reinforcing member 3 describes a form in which the jack 31 is attached to one end side of the rod-shaped member 32. In the present invention, although not shown, the reinforcing member 3 is provided at both ends of the rod-shaped member 32. A jack 31 may be attached to the side, or a rod-shaped member 32 may be attached to both ends of the jack 31. Further, in the present invention, the reinforcing member 3 may be composed of only the rod-shaped member 32 by omitting the configuration of the jack 31, or may be composed of only the rod-shaped member 32 by omitting the configuration of the rod-shaped member 32 and only the jack 31. It may be composed of.

In the installation process, first, the reinforcing member 3 is erected between the projecting portions 9 and 9 arranged on both sides of the repair target area 20. In this installation step, the reinforcing member 3 is erected between the projecting portions 9 and 9 projecting from the end portion 1a and the intermediate portion 1c in the material axial direction X of the PC structure 1. At this time, in the PC structure 1, the projecting portions 9 and 9 are arranged on both sides of the lumber axial direction X with the repair target area 20 interposed therebetween, so that the reinforcing member 3 is located between the projecting portions 9 and 9. By erection, the reinforcing member 3 extended in the longitudinal direction of the tension member 8 is installed across the repair target area 20.

Further, in the installation process, the reinforcing member 3 is installed so as to face the surface different from the surface on which the repair target portion 2 is formed. That is, in the present embodiment, since the repair target portion 2 is formed on the bottom surface 11 of the PC structure 1, the reinforcing member 3 is arranged so as to face the side surface 13 of the PC structure 1.

In the installation process, the reinforcing member 3 may be installed so as to face the surface on which the repair target portion 2 is formed. At this time, in the installation step, when the repair target portion 2 is formed on the bottom surface 11 of the PC structure 1, the reinforcing member 3 may be arranged so as to face the bottom surface 11 of the PC structure, or the PC structure may be arranged. When the repair target portion 2 is formed on the side surface 13 of the object 1, the reinforcing member 3 may be arranged so as to face the side surface 13 of the PC structure 1.

In the installation step, the reinforcing members 3 are arranged on both sides of the PC structure 1 so as to face the side surfaces 13 and 13 of the PC structure 1, respectively.

When the reinforcing member 3 is installed in the installation process, the jack 31 of the reinforcing member 3 is extended in the material axial direction X so that the jack 31 comes into contact with the projecting portion 9 provided at the end portion 1a of the PC structure 1. At the same time, the rod-shaped member 32 is brought into contact with the projecting portion 9 provided in the intermediate portion 1c of the PC structure 1, and the reinforcing member 3 is installed. Further, when installing the reinforcing member 3 in the installation process, by extending the jack 31 in the longitudinal direction of the reinforcing member 3, the reinforcing member 3 is pressed against the projecting portion 9 and a pressing force is applied to the reinforcing member 3. In this state, the reinforcing member 3 may be installed.

Next, in the repair step, first, the concrete in the repair target portion 2 is scraped to a predetermined depth by an electric breaker, a water jet, or the like. At this time, the entire surface of the concrete in the repair target portion 2 may be chipped in the depth direction, or only a part of the concrete surface in the repair target portion 2 may be chipped in the depth direction.

In the repair process, the concrete scraping work in the repair target portion 2 causes the prestress (compressive force) borne by the repair target portion 2 to be borne by the reinforcing member 3 installed in the installation process. Then, in the repair process, in a state where the reinforcing member 3 installed in the installation process bears the compressive force, new concrete is placed in place of the chipped concrete to repair the repair target portion 2.

Next, in the removal step, the reinforcing member 3 is removed after the new concrete placed in the repair step is hardened. Regarding the removal of the reinforcing member 3, the jack 31 and the rod-shaped member 32 are separated from the projecting portion 9 by contracting the jack 31 in the material axial direction X, and the reinforcing member 3 is removed.

In the removal process, by removing the reinforcing member 3, the compressive force borne by the reinforcing member 3 can be borne by the new concrete cast and hardened in the repair process, resulting in a new hardened concrete. Prestress can be introduced.

The method for repairing a PC structure to which the present invention is applied is provided with an installation step of installing a reinforcing member 3 extended in the longitudinal direction of the tension member 8 across the repair target area 20 to reinforce the reinforcement installed in the installation process. With the compressive force applied to the member 3, new concrete can be placed in place of the chipped concrete to repair the repair target portion 2. Therefore, the method for repairing the PC structure to which the present invention is applied can prevent the PC structure 1 from buckling when the PC structure 1 is repaired.

The method for repairing a PC structure to which the present invention is applied requires only scraping the damaged repair target portion 2 in the repair step, and is the end portion of the PC structure as is performed by the conventional method for repairing a PC structure. Since it is not necessary to cut the concrete up to the point and the area for chipping the concrete can be reduced, the time for the chipping work of the concrete can be shortened and the construction period can be shortened.

The method for repairing a PC structure to which the present invention is applied omits the work of installing an intermediate fixing tool attached to a tension material for introducing a new prestress used in the conventional method for repairing a PC structure. Since the repair target portion 2 can be repaired, the construction period can be shortened.

In the method of repairing a PC structure to which the present invention is applied, a reinforcing member 3 is provided on each of the projecting portions 9 and 9 of the PC structure 1 which are projected in advance on both sides of the lumber axial direction X with the repair target area 20 interposed therebetween. Since it is erected, it is possible to easily install the reinforcing member 3 that bears the compressive force in the repair process, and as a result, the construction period can be shortened.

In the repair method of the PC structure to which the present invention is applied, the reinforcing member 3 that can be expanded and contracted in the material axial direction X is used, so that the reinforcing member 3 is installed in the installation process and the reinforcing member 3 is removed in the removal process. The work to be done can be easily performed, and as a result, the construction period can be shortened.

In the method for repairing a PC structure to which the present invention is applied, the reinforcing member 3 used for repairing the repair target portion 2 in the PC structure 1 is replaced with the reinforcing member 3 in the PC structure 1 by removing the reinforcing member 3 in the removing step. Since it can be diverted when repairing the repair target portion 2 of the above or when repairing the repair target portion 2 in another PC structure 1, it is possible to reduce the construction cost.

Further, in the method of repairing a PC structure to which the present invention is applied, the reinforcing member 3 is installed between the projecting portions 9 in a state where a pressing force is applied in the longitudinal direction of the reinforcing member 3 in the installation process. That is, since the reinforcing member 3 is in a state where the pressing force is applied, a force is applied so that both the projecting portions 9 and 9 are separated from each other on both sides in the material axial direction X. Therefore, in the method of repairing a PC structure to which the present invention is applied, when the reinforcing member 3 is removed in the removing step, the forces acting on both the projecting portions 9 and 9 try to return in a direction approaching each other. As a result, it is possible to introduce a large amount of prestress to the new concrete that has been cast and hardened in the repair process.

In the method of repairing a PC structure to which the present invention is applied, the reinforcing member 3 is installed so as to face a surface different from the surface on which the repair target portion 2 is formed in the installation process. That is, in the method for repairing a PC structure to which the present invention is applied, since the reinforcing member 3 is not arranged so as to face the surface on which the repair target portion 2 is formed in the installation process, the concrete in the repair target portion 2 is scraped in the repair process. The work of placing new concrete on the scraped concrete and the work of placing new concrete on the scraped concrete can be easily performed without being hindered by the reinforcing member 3, and as a result, the construction period can be shortened. It will be possible.

FIG. 4A shows, in the method of repairing a PC structure to which the present invention is applied, reinforcing members 3 are erected on the fixing members 4 and 4 attached to both sides of the lumber axial direction X with the repair target area 20 interposed therebetween. It is a side view which shows the PC structure 1, and FIG. 4 (b) is a cross-sectional view of 4A-4A'of FIG. 4 (a).

The PC structure 1 is connected to another PC structure 1 adjacent to each other in the material axis orthogonal direction Y via a concrete padding portion 91.

As the fixing member 4, a synthetic member made of steel, concrete, steel, concrete, or the like is used for fixing the reinforcing member 3. The fixing member 4 is arranged so as to project so as to project in the material axis orthogonal direction Y of the PC structure 1, and is attached to both side surfaces 13 and 13 of the PC structure 1, respectively.

In the method of repairing a PC structure to which the present invention is applied, in the installation process, the fixing members 4 and 4 for fixing the reinforcing members 3 are provided on both sides of the repair target area 20 on both sides of the side surface 13 of the PC structure 1. A reinforcing member 3 is erected between the fixing members 4 and 4, respectively. Further, when the reinforcing member 3 is installed in the installation process, the jack 31 is extended in the longitudinal direction of the reinforcing member 3, so that the reinforcing member 3 is pressed against the fixing member 4 and a pressing force is applied to the reinforcing member 3. Then, the reinforcing member 3 may be installed between the fixing members 4.

To attach the fixing member 4, for example, when concrete is used as the fixing member 4, a formwork having a predetermined size is installed on the side surface 13 of the PC structure 1, and concrete is placed in the formwork. , The fixing member 4 is attached to the side surface 13.

The attachment of the fixing member 4 is not limited to this, and the side surface 13 of the PC structure 1 is drilled with a drill, a water jet, a long bit drill, or the like, and the drilled hole is filled with a bolt as the fixing member 4 or a PC. The fixing member 4 may be attached to the side surface 13 by inserting a steel material, a urbon material, or the like. Further, in the mounting work of the fixing member 4, when the drilling work is not performed, the fixing member 4 may be mounted on the side surface 13 by driving an anchor as the fixing member 4 into the side surface 13.

In the embodiment shown in FIG. 4, the fixing member 4 has been described as being attached to the side surface 13 of the PC structure, but the present invention is not limited to this, and the fixing member 4 may be attached to the bottom surface 11, the top surface 12, or the like of the PC structure. good.

The method for repairing a PC structure to which the present invention is applied is particularly reinforced when the reinforcing member 3 is erected on each of the fixing members 4 and 4 attached to both sides of the material axial direction X with the repair target area 20 interposed therebetween. Since the length of the member 3 in the material axial direction X is sufficient to be the length between the fixing members 4 and 4 to be erected, the reinforcing member 3 is erected on each of the projecting portions 9 and 9 of the PC structure 1. The length of the reinforcing member 3 in the material axial direction X can be shortened, and the construction cost can be further reduced.

In the method of repairing the PC structure to which the present invention is applied, in the removing step, the fixing member 4 may be removed at the same time as the reinforcing member 3 is removed, or only the reinforcing member 3 is removed to remove the fixing member 4. May be left in the PC structure 1.

FIG. 5A is a side view showing the PC structure 1 in which the reinforcing member 3 is erected between the projecting portion 9 and the fixing member 4 in the method for repairing the PC structure to which the present invention is applied. (B) is a cross-sectional view of 5A-5A'of FIG. 5 (a), and FIG. 5 (c) is a cross-sectional view of 5B-5B'of FIG. 5 (a).

In the method for repairing a PC structure to which the present invention is applied, in the installation process, the projecting portion 9 is projected by using the PC structure 1 having the projecting portion 9 projecting in advance in the material axis orthogonal direction Y. A fixing member 4 for attaching the reinforcing member 3 is attached to the opposite side of the projecting portion 9 with the repair target area 20 interposed therebetween, and the reinforcing member 3 is erected between the projecting portion 9 and the fixing member 4. Further, when installing the reinforcing member 3 in the installation process, by extending the jack 31 in the longitudinal direction of the reinforcing member 3, the reinforcing member 3 is pressed against the projecting portion 9 and the fixing member 4 and pushed against the reinforcing member 3. The reinforcing member 3 may be installed between the projecting portion 9 and the fixing member 4 with the pressure applied.

In the method of repairing a PC structure to which the present invention is applied, in particular, when the reinforcing member 3 is erected between the projecting portion 9 and the fixing member 4, only the fixing member 4 on one side is used as the PC structure in the installation process. Since it may be attached to 1, the construction can be simplified as compared with the case where the reinforcing member 3 is erected on each of the fixing members 4 and 4 attached to both sides of the material axial direction X across the repair target area 20, and as a result, the construction can be simplified. It is possible to reduce the construction cost.

In the method of repairing a PC structure to which the present invention is applied, in particular, when the reinforcing member 3 is erected between the projecting portion 9 and the fixing member 4, the length of the reinforcing member 3 in the material axial direction X is projected. Since the length between the installation portion 9 and the fixing member 4 is sufficient, the length of the reinforcing member 3 in the material axis direction X is longer than that in the case where the reinforcing member 3 is erected on each of the projecting portions 9 and 9 of the PC structure 1. It is possible to shorten the length and further reduce the construction cost.

FIG. 6A is a cross-sectional view showing a PC structure 1 provided with a tension member 81 having a material axis orthogonal direction Y as a longitudinal direction in a method for repairing a PC structure to which the present invention is applied. (B) is a plan view of the PC structure 1.

In the PC structure 1, prestress is introduced in the material axial direction X by the tension material 8. Further, the PC structure 1 is connected to another PC structure 1 adjacent to each other in the material axis orthogonal direction Y via a concrete padding portion 91. A tension member 81 having the material axis orthogonal direction Y as the longitudinal direction is arranged in the PC structure 1 and the filling portion 91 adjacent to each other. As a result, prestress is introduced into the PC structure 1 even in the direction Y orthogonal to the material axis.

In the PC structure 1 according to the embodiment shown in FIG. 6, the repair target portion 2 includes the upper surfaces 12 and 12 of the PC structures 1 and 1 adjacent to each other in the material axis orthogonal direction Y, and these PC structures 1 and 1. Are formed in a padding portion 91 that connects the two to each other.

The PC structure 1 includes a repair target area 20 which is an area from one end 2a to the other end 2b of the material axial direction X horizontally parallel to the longitudinal direction of the tension material 8 in the repair target portion 2, and the repair target portion 2. Has a repair target area 21 which is an area from one end 2c to the other end 2d in the material axis orthogonal direction Y horizontally parallel to the longitudinal direction of the tension member 81. That is, the repair target area 20 includes a virtual line 20a cut vertically with respect to the material axis direction X so as to include one end portion 2a of the material axis direction X of the repair target portion 2, and the material axis direction of the repair target portion 2. It is an area between the virtual line 20b cut vertically with respect to the material axis direction X so as to include the other end 2b of X. Further, the repair target area 21 includes a virtual line 21c cut vertically with respect to the material axis orthogonal direction Y so as to include one end portion 2c of the material axis orthogonal direction Y of the repair target part 2, and the material of the repair target part 2. It is an area between the virtual line 20d cut vertically with respect to the material axis orthogonal direction Y so as to include the other end 2d in the axis orthogonal direction Y.

As the reinforcing member 3 installed across the repair target area 21, a reinforcing member 3 that can be expanded and contracted in the material axis orthogonal direction Y is used.

In the method of repairing a PC structure to which the present invention is applied, in the installation process, the fixing members 4 and 4 for fixing the reinforcing members 3 on both sides of the repair target area 20 are provided on the upper surface 12 of the PC structure 1. A reinforcing member 3 is erected between the fixing members 4 and 4, respectively. Further, when the reinforcing member 3 is installed in the installation process, the jack 31 is extended in the longitudinal direction of the reinforcing member 3, so that the reinforcing member 3 is pressed against the fixing member 4 and a pressing force is applied to the reinforcing member 3. Then, the reinforcing member 3 may be installed between the fixing members 4.

Further, in the method of repairing a PC structure to which the present invention is applied, in the installation process, the fixing members 4 and 4 for fixing the reinforcing members 3 on both sides of the repair target area 21 are attached to the PC structure 1. It is attached to the upper surface 12 respectively, and the reinforcing member 3 is erected between the fixing members 4 and 4, respectively. Further, when the reinforcing member 3 is installed in the installation process, the jack 31 is extended in the longitudinal direction of the reinforcing member 3, so that the reinforcing member 3 is pressed against the fixing member 4 and a pressing force is applied to the reinforcing member 3. Then, the reinforcing member 3 may be installed between the fixing members 4.

The method for repairing a PC structure to which the present invention is applied is particularly reinforced when the reinforcing member 3 is erected on each of the fixing members 4 and 4 attached to both sides of the material axial direction X with the repair target area 20 interposed therebetween. Since the length of the member 3 in the material axis direction X is sufficient to be the length between the respective fixing members 4 and 4 to be erected, the length of the material axis direction X of the reinforcing member 3 can be shortened. It is possible to reduce the construction cost.

The method for repairing a PC structure to which the present invention is applied is particularly when the reinforcing member 3 is erected on each of the fixing members 4 and 4 attached to both sides of the material axis orthogonal direction Y with the repair target area 21 interposed therebetween. Since the length of the reinforcing member 3 in the orthogonal direction Y of the material axis is sufficient for the length between the fixing members 4 and 4 to be erected, it is possible to shorten the length of the reinforcing member 3 in the orthogonal direction of the material axis Y. It is possible to further reduce the construction cost.

As described above, the method of repairing the PC structure to which the present invention is applied is the PC structure 1 in which the tension member 8 extended in the lumber direction X and the tension member 81 extended in the lumber orthogonal direction Y are arranged. Can also be applied.

In the method of repairing the PC structure to which the present invention is applied, in the removing step, the fixing member 4 may be removed at the same time as the reinforcing member 3 is removed, or only the reinforcing member 3 is removed to remove the fixing member 4. May be left in the PC structure 1.

Although not shown, the method of repairing the PC structure to which the present invention is applied includes the upper surface 12 on which the repair target portion 2 is formed and the bottom surface 11 which is the back surface of the upper surface 12 on which the repair target portion 2 is formed. The reinforcing member 3 may be installed so as to face the lower surface 16.

FIG. 7 is a perspective view showing the PC structure 1 in which the box girder is used in the method for repairing the PC structure to which the present invention is applied.

As the PC structure 1, a box girder having an outer surface 10 composed of a bottom surface 11, an upper surface 12 and a side surface 13 and an inner surface 14 surrounding an internal space 15 is used. In the PC structure 1, the tension material 8 is arranged in the concrete. In the PC structure 1, the repair target portion 2 is formed on the bottom surface 11 of the outer surface 10.

FIG. 8 shows, in the method of repairing a PC structure to which the present invention is applied, a reinforcing member 3 is erected on each of the projecting portions 9 and 9 which are projected in advance on both sides of the material axial direction X with the repair target area 20 interposed therebetween. It is a side view which shows the PC structure 1 as a box girder, and FIG. 8 (b) is a cross-sectional view of 8A-8A'of FIG. 8 (a).

The PC structure 1 has projecting portions 9 projecting in the material axis orthogonal direction Y at both end portions 1a and 1b in the material axis direction X. The projecting portion 9 is a so-called horizontal girder.

In the method of repairing a PC structure to which the present invention is applied, first, in the installation process, a reinforcing member 3 is erected between the projecting portions 9 and 9 arranged on both sides of the repair target area 20. In this installation step, the jack 31, the rod-shaped member 32, and the stiffener 33 of the reinforcing member 3 are installed in the space 15 inside the PC structure 1. In the installation process, buckling of the reinforcing member 3 can be prevented by installing a stiffener 33 such as a jack extended in the material axis orthogonal direction Y and the height direction Z, respectively, in the internal space 15. ..

In the method of repairing a PC structure to which the present invention is applied, first, in the installation process, a reinforcing member 3 is erected between the projecting portions 9 and 9 arranged on both sides of the repair target area 20. In this installation step, the reinforcing member 3 is erected between the projecting portions 9 and 9 projecting from both end portions 1a and 1b in the material axial direction X of the PC structure 1. At this time, in the PC structure 1, since the projecting portions 9 and 9 are arranged on both sides of the lumber axial direction X with the repair target area 20 interposed therebetween, the reinforcing member 3 is placed between the projecting portions 9 and 9. By erection, the reinforcing member 3 extended in the longitudinal direction of the tension member 8 is installed across the repair target area 20.

The method for repairing a PC structure to which the present invention is applied is provided with an installation step of installing a reinforcing member 3 extended in the longitudinal direction of the tension member 8 across the repair target area 20 to reinforce the reinforcement installed in the installation process. With the compressive force applied to the member 3, new concrete can be placed in place of the chipped concrete to repair the repair target portion 2. Therefore, the method for repairing the PC structure to which the present invention is applied can prevent the PC structure 1 from buckling when the PC structure 1 is repaired.

Further, in the repair method of the PC structure to which the present invention is applied, it is only necessary to scrape only the damaged repair target portion 2 in the repair step, and the PC structure as is performed by the conventional method of repairing the PC structure. Since it is not necessary to cut concrete up to the end and the area for chipping concrete can be reduced, the time for chipping concrete can be shortened and the construction period can be shortened. ..

In the present embodiment, in the installation process, when the repair target portion 2 is formed on the outer surface 10 of the PC structure 1, the reinforcing member 3 is arranged so as to face the inner surface 14 of the PC structure 1. Therefore, in the method for repairing a PC structure to which the present invention is applied, since the reinforcing member 3 is not arranged so as to face the surface on which the repair target portion 2 is formed in the installation process, the concrete in the repair target portion 2 is placed in the repair process. The work of scraping and the work of placing new concrete on the scraped concrete can be easily performed without being hindered by the reinforcing member 3, and as a result, the construction period can be shortened. Is possible.

Further, in the method of repairing a PC structure to which the present invention is applied, by installing the reinforcing member 3 in the space 15 inside the PC structure 1, the reinforcing member 3 does not fall below the PC structure 1. It will be possible to construct safely.

FIG. 9A shows a reinforcing member in each of the projecting portions 91 and 91 projecting in advance on both sides of the material axial direction X across the repair target area 20 in the method for repairing a PC structure to which the present invention is applied. 3 is a side sectional view showing a PC structure 1 as a box girder on which 3 is erected. Although the tension material 8 is omitted in FIG. 9A, it is assumed that the tension material 8 is extended with the material axial direction X as the longitudinal direction.

The PC structure 1 is provided in advance in the internal space 15 with a projecting portion 91 as an intermediate partition wall at a predetermined interval in the material axis direction X. The projecting portion 91 as an intermediate partition wall is provided to resist the cross-sectional deformation of the PC structure 1.

In the method of repairing a PC structure to which the present invention is applied, in the installation process, a reinforcing member 3 is erected between the projecting portions 91 and 91 arranged on both sides of the repair target area 20 and the tension member 8 is installed. The reinforcing member 3 extended in the longitudinal direction of the above is installed across the repair target area 20.

The method for repairing a PC structure to which the present invention is applied is provided with an installation step of installing a reinforcing member 3 extended in the longitudinal direction of the tension member 8 across the repair target area 20 to reinforce the reinforcement installed in the installation process. With the compressive force applied to the member 3, new concrete can be placed in place of the chipped concrete to repair the repair target portion 2. Therefore, the method for repairing the PC structure to which the present invention is applied can prevent the PC structure 1 from buckling when the PC structure 1 is repaired.

Further, in the repair method of the PC structure to which the present invention is applied, in the repair process, only the damaged repair target portion 2 needs to be scraped, and the area for scraping the concrete can be reduced, so that the concrete is scraped. The work time can be shortened and the construction period can be shortened.

FIG. 9B shows, in the method of repairing a PC structure to which the present invention is applied, reinforcing members 3 are erected on the fixing members 4 and 4 attached to both sides of the lumber axial direction X with the repair target area 20 interposed therebetween. It is a side sectional view which shows the PC structure 1 as a box girder. Although the tension material 8 is omitted in FIG. 9B, it is assumed that the tension material 8 is extended with the material axial direction X as the longitudinal direction.

In the method of repairing a PC structure to which the present invention is applied, in the installation process, the fixing members 4 and 4 for fixing the reinforcing members 3 on both sides of the repair target area 20 are provided on the inner surface 14 of the PC structure 1. A reinforcing member 3 is erected between the fixing members 4 and 4, respectively.

The method for repairing a PC structure to which the present invention is applied is provided with an installation step of installing a reinforcing member 3 extended in the longitudinal direction of the tension member 8 across the repair target area 20 to reinforce the reinforcement installed in the installation process. With the compressive force applied to the member 3, new concrete can be placed in place of the chipped concrete to repair the repair target portion 2. Therefore, the method for repairing the PC structure to which the present invention is applied can prevent the PC structure 1 from buckling when the PC structure 1 is repaired.

Further, in the repair method of the PC structure to which the present invention is applied, in the repair process, only the damaged repair target portion 2 needs to be scraped, and the area for scraping the concrete can be reduced, so that the concrete is scraped. The work time can be shortened and the construction period can be shortened.

FIG. 10 is a side sectional view showing a PC structure 1 provided with a tension material 8 as an outer cable in a method for repairing a PC structure to which the present invention is applied.

In the PC structure 1, a tension material 8 as an outer cable is provided in the internal space 15, and the projecting portion 92 as a fixing portion for fixing the tension material 8 and the tension material 8 are deflected. It has a projecting portion 93 as a deflecting portion for arranging. The projecting portion 92 and the projecting portion 93 are preliminarily projected from the inner surface 14 of the PC structure 1 in the direction Y perpendicular to the material axis. The PC structure 1 is not limited to the one in which the tension member 8 as an outer cable is provided in the internal space 15, and may be one in which the tension material 8 is provided on the outer surface 10 side.

In the method for repairing a PC structure to which the present invention is applied, in the installation process, a PC structure having the projecting portions 92, 93 projecting in advance in the direction Y orthogonal to the material axis is used, and the projecting portions 92, 93 are provided with the projecting portions 92, 93. A fixing member 4 for attaching the reinforcing member 3 is attached to the opposite side of the projecting portions 92 and 93 with the repair target area 20 sandwiched between the projecting surfaces. Then, in the installation process, the reinforcing member 3 is erected between the projecting portion 92 and the fixing member 4 and between the projecting portion 93 and the fixing member 4, and the reinforcing member is extended in the longitudinal direction of the tension member 8. 3 is installed across the repair target area 20.

Although not shown, in the method of repairing a PC structure to which the present invention is applied, in the installation process, a reinforcing member is provided between the projecting portions 92 and 92 arranged on both sides of the repair target area 20. 3 may be erected, and the reinforcing member 3 extended in the longitudinal direction of the tension member 8 may be installed across the repair target area 20. Further, although not shown, in the method of repairing a PC structure to which the present invention is applied, in the installation process, a reinforcing member is provided between the projecting portions 93 and 93 arranged on both sides of the repair target area 20. 3 may be erected, and the reinforcing member 3 extended in the longitudinal direction of the tension member 8 may be installed across the repair target area 20.

The method for repairing a PC structure to which the present invention is applied compresses the longitudinal reinforcing member 3 of the tension member 8 into the reinforcing member 3 installed in the installation process by providing an installation step of installing the tension member 8 across the repair target area 20. It is possible to repair the repair target portion 2 by placing new concrete in place of the scraped concrete in a state where the force is applied. Therefore, the method for repairing the PC structure to which the present invention is applied can prevent the PC structure 1 from buckling when the PC structure 1 is repaired.

In the repair process of the PC structure to which the present invention is applied, only the damaged repair target portion 2 needs to be scraped, and the area for scraping the concrete can be reduced. The time can be shortened and the construction period can be shortened.

In the above-described form, the mode in which the tension member 8 as the outer cable is provided on the PC structure 1 as the box girder has been described, but the PC structure 1 as the girder having a substantially T-shaped cross section is outside. A tension member 8 as a cable may be provided.

Although the examples of the embodiments of the present invention have been described in detail above, all of the above-described embodiments are merely examples of specific examples in carrying out the present invention, and the technical aspects of the present invention are thereby used. The scope should not be construed in a limited way.

1: PC structure 1a: end 1b: end 1c: middle part 10: outer surface 11: bottom surface 12: top surface 13: side surface 14: inner surface 15: space 2: repair target part 2a: end part 2b: end part 20: Area to be repaired 21: Area to be repaired 3: Reinforcing member 31: Jack 32: Rod-shaped member 33: Stiffening material 4: Fixing member 8: Tension material 9: Protruding part 91: Protruding part 92: Protruding part 93: Protruding part Setting part 99: Filling part X: Material axis direction Y: Material axis orthogonal direction Z: Height direction

Claims (5)

It is a repair method for PC structures formed by introducing prestress into concrete by tension material.
A reinforcing member extended in the longitudinal direction of the tension material is installed across the repair target area, which is an area from one end to the other end in the direction parallel to the longitudinal direction of the tension material in the repair target portion to be repaired. Installation process and
A repair process in which the concrete in the repair target portion is scraped and new concrete is placed in place of the scraped concrete to repair the repair target portion.
It is provided with a removal step of removing the reinforcing member after the new concrete placed by the repair step is hardened .
In the installation step, the PC structure having a projecting portion projecting in advance in the direction orthogonal to the lumber axis is used, and the projecting portion is located between the projecting portions arranged on both sides of the repair target area. A method of repairing a PC structure, which comprises installing a reinforcing member . The method for repairing a PC structure according to claim 1, wherein in the installation step, the reinforcing member is installed facing the surface different from the surface on which the repair target portion is formed. The PC structure is a box girder in which a space is formed inside.
The method for repairing a PC structure according to claim 1 or 2 , wherein in the installation step, the reinforcing member is arranged in a space inside the PC structure. The installation step according to claim 1 to 3 , wherein the reinforcing member is installed so as to face the surface on which the repair target portion is formed and the back surface of the surface on which the repair target portion is formed. The method for repairing a PC structure according to any one of the above. The PC structure according to any one of claims 1 to 4 , wherein in the installation step, the reinforcing member is installed in a state where a pressing force is applied toward the outside in the longitudinal direction of the reinforcing member. How to repair things.

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