KR100271230B1 - Hybrid method for repairing and reinforcing cracked beams of bridge using external bent pre-stressed wire - Google Patents

Abstract

PURPOSE: A method for reinforcing a bridge mold is provided to supply a reliable and safe mold reinforcing method by using an attaching typed repairing process with a stiffener and a repairing process with a PS steel wire. CONSTITUTION: A method for reinforcing a bridge mold comprises a first stage installing at least one middle supporting bracket(42) on a middle portion of a lower end of a bridge mold(32); a second stage locating an anchorage fixing a steel wire on both end portions of the bridge mold; and a third stage repairing dropping of the bridge mold by extending the steel wire supported on the anchorage. A PS steel wire repairs process repairing crack of the damaged bridge mold by extending the PS steel wire. Moreover, a first stiffener attaching typed reinforcing process adhering the first stiffener(50) on a floor portion of the bridge mold.

Description

Hybrid method for repairing and reinforcing cracked beams of bridge using external bent pre-stressed wire}

The present invention relates to a complex reinforcement method of a damaged bridge mold using a bent external steel wire to repair and reinforce a concrete structure such as a bridge mold severely damaged by excessive load or traffic increase, More specifically, in a structure such as a concrete structure such as a bridge, when the mold collapses due to cracks and deterioration, cracks are severely used by using a repair method using a PS steel wire and a reinforcement method of attaching a reinforcement material. The present invention relates to a complex reinforcement method of damaged bridge molds using a bent external steel wire to repair and reinforce the damaged bridge molds.

In general, in a concrete structure, when the load capacity is insufficient, that is, as shown in FIG. 1, when the bridge mold 32 installed on the bridge 30 does not overcome the load, a bending tensile crack due to bending or deflection occurs and ultimately, Leads to the collapse of the bridge. Currently, the repair and reinforcement of the bridge is widely used external prestressing method using PS steel wire, or adhesive repair reinforcement method using steel sheet or carbon fiber. The most representative method of repairing reinforcement method is steel reinforcement repair method with steel plate injection method and crimping method. In case of carbon fiber or glass fiber, crimping method is typical repair method and injection method is used for steel plate reinforcement method. The reinforcing material is a method of injecting epoxy resin therebetween at intervals of about 2 to 5 millimeters (mm) from an existing structure. In the case of injection method, it is a method used when it is difficult to use the crimping method because the spacing between the reinforcement and the existing structure is not constant because the construction state of the existing structure is poor. In the case of the steel plate crimping method, epoxy is applied between the surface of the structure and the adhesive surface of the reinforcement to directly attach the reinforcement to the structure.When the surface state of the existing structure is good, it is possible to attach the reinforcing member directly to the structure. It is the applicable method. In addition, the crimping repair reinforcement method using carbon fiber or glass fiber is similar to the crimping method of steel sheet, but since the reinforcement itself is not rigid, construction is similar to wallpaper wallpaper.

All of these attachable repair reinforcement methods are appropriately cut and processed by reinforcing members, which are difficult to work with due to the heavy weight of these reinforcing materials. It is light and easy to work with. It uses various kinds of special fiber materials such as carbon fiber, glass fiber, boron fiber, Keveler fiber, aramid fiber and so on. Among these special fiber materials, carbon fiber is the most widely used material based on the research results, and other fibers are still in use.

However, such a repair and repair reinforcement method is difficult to take care in quality control because problems such as dropping of the reinforcement may occur later if the quality control of materials and construction is not thoroughly.

In addition, the external prestressing method using the PS steel wire is also a very promising repair reinforcement method. There are many bridges that can be repaired and reinforced using the PS steel wire. The maintenance reinforcement method using the PS steel wire is classified into three types according to how the anchor of the end is installed. That is, the anchor of the end is installed in the abdomen significantly away from the point, the method of fixing using anchor bolts to the mold surface near the point, and the method of surrounding the end of the mold with a steel bracket. As a simple example of such a reinforcement technique using a PS steel wire, a method of closing a crack by tensioning a tension member of a main ship through a fixing device in which a PS steel wire is disposed to surround a side lower end of a bridge mold in which a crack has occurred is known. In addition, as another example, a repair method and a repair device for a bridge mold using a steel wire disclosed in Korean Patent Publication No. 96-4668. In this method, the PS steel wire is guided and supported by using both end brackets and intermediate support brackets, and the steel wire is tensioned through a fixing fixture fixed to the both end support brackets, thereby raising and repairing the portion cracked by the deflection of the bridge mold upwards. Be sure to

However, this method of repairing bridge molds using PS steel wires also stresses the edges of the PS steel wires and brackets when the PS steel wires or brackets are tense, or at the edges of parts where the PS steel wires and the bridge molds directly or indirectly contact each other. This is concentrated, or the stress is unevenly acted between the bracket and the bracket may cause cracking in a portion of the bridge mold, which may lead to fracture. The effect is noticeably diminished.

In addition, in the case of using only the above-described repairing reinforcement method using a steel plate, etc., there is a problem that the repair reinforcement effect is very small in the state that a lot of cracks and sagging occurs in the existing bridge, using only the external prestressing method using PS steel In this case, there is a limit in applying tensile force due to stress concentration in the anchorage, and there is a problem that it is very difficult to determine the tension force to be applied to external prestressing if the tension force in the existing PS beam is not known. Therefore, when the damage of the existing bridge is considerably progressed, the combined reinforcement reinforcement method and the reinforcement reinforcement method using the PS steel wire are combined to secure durability and reliability after the bridge repair.

In addition, if the damage of the bridge mold is not great or the reinforcement is sufficient only by the attachment repair reinforcement method and the attachment force of the reinforcement is complete, after the completion of the repair reinforcement process of the present invention, the PS steel wire is removed to increase the load capacity only by the attachment repair reinforcement method. It is also possible to expect. This is a slight modification of the existing retrofit reinforcement method, and it is also a method to compensate for the difference between the existing experiment and the field conditions to prove the effectiveness of the retrofit reinforcement method. In other words, in the laboratory, repair reinforcement effect is measured by attaching reinforcement reinforcement to newly manufactured beam which is not damaged, but in actual bridge structure, the mold of bridge is already damaged by cracking and sagging due to self and dead weight. The state is in a state where deformation has occurred over a long period of time, and the internal stress is redistributed due to dry shrinkage or creep of the concrete. Therefore, if prestressing is performed with PS steel wire prior to attachable reinforcement, these residual stresses in existing bridges can be removed. Therefore, the reinforcement in real bridge is expected to have the same reinforcement effect as in the laboratory. Because.

Using the bent external PS steel wire as in the present invention is a structurally more advantageous form of reinforcement than when using a straight external steel wire. This is because when the external steel wire is bent, due to the upward force generated in the bent portion, in addition to applying the compressive force due to the tension of the steel wire to the concrete, it is possible to more effectively enhance the load capacity of the bridge. However, when using the bent PS steel wire, there is a problem in that it is difficult to attach the adhesive reinforcement because of the brackets located in the middle of the mold. Therefore, it is necessary to change the design of the intermediate bracket and improve the installation method to achieve the reinforcement effect to be achieved in the present invention.

The technical problem to be solved by the present invention, in order to solve the above-mentioned conventional problems, the repair reinforcement process using the PS steel wire bent in the mold in the case of a severely damaged bridge that has already undergone a significant cracking process and the adhesive repair using the reinforcement The combined use of the reinforcement process provides a safer, more durable, and more engineering and reliable method for repairing bridge molds.

1 is a side view showing flexural tensile cracks in damaged bridge molds.

FIG. 2 is a side view illustrating the repair process step of closing the crack by pulling the bent PS steel wire to the damaged bridge mold of FIG.

FIG. 3 is a side view for explaining a step of locally attaching a first reinforcing material by an attachable reinforcement method to a cracked portion of a bridge mold bottom after closing the crack using the PS steel wire of FIG. 2.

4 is a side view for explaining a step of attaching a second reinforcing material as a whole on the bottom of the bridge mold after attaching the first reinforcing material of FIG.

FIG. 5 is a side view for explaining the step of attaching the third reinforcement to the bottom and the side of the bridge mold as a whole after attaching the second reinforcement of FIG. 4.

FIG. 6 is a view for explaining a method of constructing a reinforcement and a saddle in a mold when attaching the reinforcement of FIGS. 3 to 5.

7 is a view for explaining the shape and installation position of the birds shown in FIG. 6 more easily.

<Description of the code | symbol about the principal part of drawing>

30 ... piers, 32 ... bridge molds

34 ... anchorage, 36 ... steel wire

40 ... slab, 42 ... intermediate support bracket

44.Horbo, 50.First reinforcement

52 ... second stiffener, 54 ... third stiffener

In order to achieve the above object, the composite reinforcement method of a damaged bridge mold using a bent external steel wire of the present invention is a method for repairing and strengthening a bridge mold in which flexural tensile cracks are generated or may be generated. Installing at least one intermediate support bracket, positioning a fixing unit for fixing the steel wire at both ends of the bridge mold, and after the fixing unit, the bracket and the steel wire are installed, the steel wire supported by the fixing unit is tensioned to sag the bridge mold. PS steel wire repair process for correcting the cracks of the damaged bridge mold by tensioning the PS steel wire damaged bridge mold including repairing; And a first reinforcement type reinforcement process for attaching the first reinforcement to the local portion of the bottom of the bridge mold.

The crack repair process using the PS steel wire may be any one of various types of PS steel wire repair and reinforcement methods that are used if the steel wire arrangement in the middle of the saddle other than the method according to the drawings presented in the present invention. The repair and reinforcement process using the PS steel wire has various methods such as a method of using a transport hole as a fixing device of the steel wire. In addition, even if there are birds in the middle, the reinforcement can be easily attached by improving the design and installation method of the birds, so that in the case of using a structurally advantageous bending external steel wire, parallel to the attachable reinforcement method is possible. It was.

Preferably the present invention further includes a second reinforcement attachment process for attaching a second reinforcement over the entire bottom of the bridge beam.

More preferably, the present invention further includes a third reinforcing material attaching process for attaching a third reinforcing material attached to surround the bottom and side surfaces of the bridge beam as a whole.

In the case of the present invention, since the degree of adhesive repair reinforcement process is a matter to be determined through expert design according to the damaged state of the bridge, it is not necessary to attach the attachment repair reinforcement process in three steps, and repair by only one step attachment. Reinforcement may be possible and, if necessary, multistage reinforcement of three or more levels is possible.

Hereinafter, with reference to the accompanying drawings, an embodiment of a complex reinforcing method of a damaged bridge mold using a bent external steel wire according to the present invention will be described in more detail.

According to FIG. 1 which shows the mold which a crack generate | occur | produced, the bridge mold 32 is put on the bridge 30, and the cross beam 44 is put between bridge molds. In addition, the slab 40 is mounted on the top of the bridge molds to provide a road for traffic of vehicles or the like. In case of damage to the structure due to increased traffic volume or heavy vehicles passing through these bridges, or if the material of the component itself such as slab 40 or mold 32 is damaged due to long-term deterioration, it is prevented. Reinforcement work is needed to do this. In the present invention, for this purpose, a repair reinforcement method using a PS steel wire and an adhesive repair reinforcement method are used in combination as shown in FIGS. 2 to 5. In particular, a feature of the present invention is that the bridge mold that has already undergone cracking is first corrected for cracking using a PS steel wire, and then repaired and reinforced by attaching at least one adhesive reinforcement locally or throughout the crack portion of the mold. If the load-bearing capacity is sufficient by the adhesive reinforcement alone, the reinforcing process may be completed only by the adhesive repair reinforcement method by removing the external steel wire that corrected the crack.

FIG. 2 is a side view for explaining a step of closing a crack generated in the mold by tensioning the PS steel wire by installing the anchor and the saddle of the mold of the bridge in which the crack is generated in FIG. 1; At this time, as described above, as a repair method using the PS steel wire can be applied to all the various types of fixing methods that have been used conventionally, in this figure will be selected in detail one method. According to FIG. 2, cracking of the damaged bridge mold 32 is corrected by tensioning the PS steel wire 36 so as to surround the damaged bridge mold 32 as a whole through the anchorage 34 supporting and guiding the PS steel wire 36. Here's how. The method applied in FIG. 2 is a fixing device for fixing the PS steel wire 36 to both ends of the bridge mold 32 of the bridge mold in order to repair and reinforce the mold 32 of the bridge in which flexural tensile cracking may occur or occur. Positioning 34, installing the steel wire 36 through the anchorage 34 so as to surround both ends of the beam, and after the steel wire 36 is installed, one or two in the middle of the mold. It installs more than one bird to tension the steel wire (36) supported in the anchorage 34 to correct the deflection of the PC beam, and at the same time generating an upward force in the middle of the mold and has a step of repairing. Here, as a way to insert the convex gap member 46 between the steel wire and the contact surface of the both ends of the beam in order to solve the stress imbalance caused by the tension of the steel wire 36, the load is not beaten or struck The portion is subjected to a force lifted up by birds connected to the tensioned PS steel wire. In this case, it may be necessary to make a hole through which the steel wire can pass through the cross beam 44 of the bridge depending on the fixing position of the end portion. Also, it is desirable to install the saddle after breaking the lower part of the existing concrete mold to make it easier to attach the reinforcement after tensioning the outer steel wire.

FIG. 3 is a side view for explaining a step of locally attaching the first reinforcement 50 by an attachment type after closing the crack using the PS steel wire of FIG. 2 and having a crack at the bottom of the bridge mold 32. . According to Figure 3, after closing the crack using the PS steel wire, the first reinforcing material 50 to cover the cracked portion is attached to the bottom of the mold, the tension force acting on the bottom when the vehicle load is applied in the future It is to be evenly transmitted to the first reinforcement 50 to increase the load capacity of the bridge. Here, as described above, the reinforcing material attaching method is applicable to both injection and compression, the material used as the reinforcing material may be used both steel sheet or special fiber material. This special fiber material uses carbon fiber, glass fiber, boron fiber, Kevlar fiber, aramid fiber, etc.

4 is a side view for explaining a step of attaching the second reinforcement 52 over the entire length to the bottom of the bridge mold after attaching the first reinforcement 50 of FIG. According to FIG. 4, as described in FIG. 3, the reinforcement is locally attached to the cracked portion of the bridge mold, and then the second reinforcement 52 is placed over the first reinforcement 50 to increase the overall load capacity of the bridge mold. Attach. Since the method of attaching the second reinforcing material 52 or the material of the reinforcing material used here is the same as those of the first reinforcing material 50, a detailed description thereof will be omitted.

FIG. 5 is a side view for explaining a step of attaching the third reinforcement 54 to the bottom and the side of the bridge mold as a whole after attaching the second reinforcement 52 of FIG. 4. After the second reinforcement 52 is attached in FIG. 4, the cracks and crack projections at the bottom of the mold are reinforced locally or entirely, but the cracks and crack projections at the sides of the mold are not repaired and in FIG. A third reinforcement 54 is attached surrounding the bottom and both sides. In addition, the third reinforcement 54 may be attached to extend to the top of the mold to cover all of the side surfaces, may include only the bottom flange of the mold, and a large shear force near the point portion of the mold is greatly applied. It may be attached so as to surround the first and second reinforcing materials 50 and 52 on both sides and the bottom only on the portion. Since the third reinforcement 54 is attached to the side and bottom of the bridge mold inside the steel wire so as not to contact the PS steel wire 36, the above-described method or material for attaching the first reinforcement 50 may be used. Will be omitted.

6 shows that when the reinforcement attached to the reinforcement 52 of FIGS. 3, 4, and 5 is bent by the saddle, the reinforcement effect does not occur properly, and since the destruction of the reinforcement attached later may start, How to install the bottom of the existing concrete mold (60) by breaking the bottom of the existing concrete mold in a proper manner, and the bottom of the saddle to coincide with the bottom of the concrete mold by injecting epoxy (61) between the existing concrete mold It is shown. In this figure, the steel wire 36 located in the saddle shows a bent shape, the reinforcing brace 62 is installed to withstand the upward force acting on the steel wire is shown, the attachment reinforcement (50) attached after the tension of the wire ) Shows the location of the in detail.

FIG. 7 is a cross-sectional view of the birds shown in order to more easily describe the shape and installation position of the birds shown in FIG. 6, showing the shape of the bracket, the position of the steel wire 36, the installation position 50 of the attachable reinforcement, and the like. , Shows the position of the anchor bolt 63 required for the installation of the birds.

After the attachment reinforcement is completed, it is also possible to remove the external PS steel wire that had a function of closing the crack so that the load capacity can be increased only by the attached reinforcement. In this case, the recovered external PS steel wire and parts may be used again in the next construction. If the degree of such damage is severe or difficult to recycle, and there is a need to secure a greater safety factor, there is no problem even if the installed steel wire is left in place.

So far, as a preferred embodiment of the present invention has been described a repair reinforcement method for attaching the first to third reinforcement sequentially after closing the crack using the PS steel wire, as another embodiment only the first reinforcement or the second reinforcement Or a third reinforcement in combination with the first reinforcement and the second reinforcement to increase the load capacity of the crack site and the crack prediction site. In addition, after the completion of the attached repair reinforcement process, the method of removing the PS steel wire used to close the crack and giving the prestressing effect to the attached reinforcing material is also included. It also includes a variety of external tension methods that are currently used to apply external prestressing.

As described above, in the case of using only the conventional reinforcing reinforcement method using a steel sheet or carbon fiber, the reinforcing reinforcement effect is very small in the state where many cracks and saggings occur in the existing bridges. In case of using only the external prestressing method, there is a limit in applying tensile force due to the concentration of stress in the anchorage, and in case of not knowing the tension of the existing PS beam, it is very difficult to determine the tension applied to the external prestressing. In order to repair and reinforce the damaged bridge mold according to the present invention, the damaged load site is closed by using a PS steel wire, and then the load carrying capacity of the structure is adopted by adopting a complex repair and reinforcement process for attaching a reinforcement to the bridge mold including the crack site. Can greatly increase the durability of the structure It works.

Claims (6)

A repair and reinforcement method for repairing a bridge mold in which flexural tensile cracking or deflection is seriously generated or may occur, the method comprising: installing at least one intermediate support bracket at an intermediate portion of a lower surface of a bridge mold, and having a steel wire at both ends of the bridge mold. Positioning the anchorage to fix the damage, and after the fixing unit, the bracket and the steel wire are installed, repairing the sagging of the bridge mold by tensioning the steel wire supported by the anchorage to damage the bridge mold by tensioning the PS steel wire PS steel wire repair process for correcting cracks in bridge molds; And a first reinforcing member attaching reinforcing step of attaching a first reinforcing material to a local portion of the bottom of the bridge mold after the PS steel wire repairing step is performed. The method of claim 1, wherein the reinforcing reinforcement process using the PS steel wire is made of a bent PS steel wire having an intermediate saddle, including a method of having a fixing device at both ends or using a transport hole in the PS beam as a fixing device. A complex repair and reinforcement method for a damaged bridge mold using a bent external steel wire, comprising the step of tensioning the bridge to facilitate the attachment of the adhesive reinforcement. 3. The method of claim 2, further comprising a second reinforcement-attached reinforcement process for attaching a second reinforcement to the bottom of the bridge mold as a whole. 4. The damaged bridge mold according to claim 3, further comprising a third reinforcement-attached repair reinforcement process for attaching a third reinforcement to surround the bottom and side of the bridge mold as a whole. Complex reinforcement method. The reinforced reinforcement according to any one of claims 1 to 4, wherein the PS reinforcement is removed by attaching and repairing the PS steel wire after completion of the attachable reinforcement process of attaching a third reinforcement which is attached to surround the bottom and side of the bridge mold as a whole. A composite repair and reinforcement method for damaged bridge molds using bent external steel wires, characterized in that the bridge molds are reinforced. The bending according to claim 1, wherein the shape and installation of the birds located at the bottom of the middle of the bridge mold do not interfere with the reinforcement of the attaching material so that the existing concrete is broken and installed to match the bottom surface of the existing concrete. Complex Repair and Reinforcement Method of Damaged Bridge Molds Using a Type External Steel Wire.

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