JP2020063598A - Hinge part reinforcement method and reinforcement structure in hinged girder bridge with pc - Google Patents

Abstract

To provide a drastic hinge part reinforcement method to reinforce a hinge part almost perfectly, and a reinforced structure that makes an entire bridge continuous to prevent sagging that exceeds design value, damage, and deterioration during construction and service; and to ensure safe and comfortable traveling performance.SOLUTION: After placing and tensile-anchoring fixing tension PC steel materials 6 into a required length onto both sides of and over a specified range of bridge girders 2 where concrete is placed into, so as to generate elastic tension, jacks are installed at specified locations within the specified range. The jacks are extruded to apply compressive force to bridge girder cross sections on both sides of the range, as well as, to further increase the elastic tension of the PC steel materials 6. With the jacks extruded, a concrete 10 is poured into and cured in the above range. After the concrete 10 is hardened, the jacks are loosened and removed to release the compressive force applied to the bridge girder cross sections on both sides of the range and release the elastic tension generated in the PC steel materials 6 so as to apply resultant stress as prestress to the concrete 10 in the above range.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method and structure for reinforcing a hinge portion of a hinged girder bridge with a PC, which may be new or existing.

  This type of continuous PC girder bridge having a hinge at the center of the span has the advantages that it can be advanced from an arbitrary pier by the hinge and can be divided into separate constructions, and the cross-sectional forces are almost the same during construction and in service. In addition, there is a type called a Gerber girder bridge in which a suitable hinge is inserted in the middle part between the supports of a continuous girder bridge, and since it has a hinge, it becomes a statically determinate structure, and there is no unreasonable stress or deformation in the superstructure. Therefore, there is an advantage that the height of the whole girder is small.

  A large number of continuous PC girder bridges having the above-mentioned hinges have been constructed for a long time, but in recent years, the hinges have been damaged due to the relaxation of the weight limit of passing vehicles and rising, or moisture from rainwater from the bridge surface. The deterioration phenomenon of the hinge part has rapidly increased due to a large amount of supply, and it is necessary to reinforce it. On highways, when a vehicle is traveling at high speed, noise and vibration generated at the hinge block the running performance, so that the hinge is made continuous so as to improve the running performance, so-called no-joint is required. ing.

  Also, in the case of new construction, when the support work cannot be constructed due to the location under the bridge, the so-called cantilever overhanging construction method is adopted in which bridge girders are sequentially constructed one block at a time from the top of the bridge to the left and right in a cantilever state. There is. In this construction method, a relocatable rail is temporarily fixed on an existing bridge block, a mobile work vehicle (wagen) is installed on the rail so that it can move forward and backward, and from this mobile work vehicle to the next new bridge block. Formwork support members and scaffolds are bulged forward and supported by suspension, formwork, reinforcing bars, PC steel materials, etc. are assembled on this support member, concrete is placed, and prestress is introduced into the block to build. It is well known to construct a field girder bridge for field construction.

  Therefore, the center closed part of the span, which was extended in a cantilever state, is in a hinge state and is still in a cantilever form, so the vibration due to the vehicle or wind that is constantly received is uneven on the left and right, so it is damaged. Not only is it easy to perform, but frequent maintenance is required, which results in high running costs.Therefore, the problem to be solved is to make the closing part that is erected from both sides and abuts at the central part into a strong partition. Have.

Various proposals have been made regarding the reinforcing structure and the reinforcing method of the hinge portion.
As a proposal for the new girder bridge, in the bridge girder constructed by the overhanging construction method, the main girder cross section of the central section that becomes the closing part of the span, The SPC girder bridge structure is characterized in that a prestress is applied to the main girder by arranging a PC steel material in a curved shape over the upper surface of the overhanging bridge block and tension-fixing the same (see Patent Document 1). ).

  According to this structure, since the PC steel material arranged on the upper part of the main girder section penetrates the center section of the span in a lap state, prestress is applied to the entire cross section of the central closed section, so that the main trunk road In this case, even if tensile stress is generated at the upper and lower ends of the cross section due to a vibration load such as a large vehicle or wind, it is canceled and the safety and durability of the entire bridge can be secured.

  In addition, as a proposal for the existing girder bridge, the existing hinge part is cut and removed in a predetermined replacement range, a frame surrounding the jack is installed together with the jack at a required position within the replacement range, and the By applying a compressive force to the cross section of the bridge girders on both sides of the replacement range by extrusion, concrete is placed and hardened in the replacement range with the jack pushed out, and after the concrete has hardened, the jack is loosened and removed with the frame. This is a method of reinforcing a hinge portion of an existing girder bridge, which is characterized by applying prestress to concrete within a replacement range (see Patent Document 2).

  According to this reinforcing method, the jack is installed and pushed out in the replacement range (replacement part), that is, the jack is operated to extend the stroke and the jack is pushed to the cross section of the bridge girder on both sides of the replacement range. By placing concrete with compressive force applied and loosening the jack after hardening the concrete (returning the stretched stroke) to remove it, prestressing the concrete within the replacement range It is possible to suppress the initial cracking during construction of the replacement section and the cracking during operation, to prevent deterioration of concrete due to water supply such as rainwater from the bridge surface, and to replace the hinge section with a continuous replacement section. That is, the tensile force is less likely to be generated and the effect of improving the stress is remarkable.

Patent Publication No. 5228161 Patent Publication of Japanese Patent No. 5716117

  According to the technique of Patent Document 1, a PC steel material is arranged in a curved shape across the upper surface of an overhanging bridge block of an adjacent partition penetrating the partition in the lower part of the cross section of the central partition and tension-fixed to form a continuous PC. Although the stress of the central closing part including the hinge part of the girder bridge has been improved, since the curved PC steel material is placed and the tension is fixed after the completion of the central closing part, the concrete generated in the bridge axial direction at the time of construction Not only cannot it be suppressed against the dry shrinkage and creep deformation of the above, but it also has the problem that it cannot be lifted against the sag that exceeds the design value that occurred in the central closing part including the hinge part during construction. ing.

  In the technique of Patent Document 2 as well, there is no connecting steel material within the replacement range at the time of construction, and there is only the jack, and the jack is sandwiched between the objects to suppress extensional deformation that occurs in the opposite direction. Since it does not work against the shrinkage that separates from each other, it cannot control the dry shrinkage and creep deformation of concrete after placing it, and it is difficult to maintain the pushing force of the jack, so loosen the jack after hardening the concrete and remove it. After that, the prestress applied to the concrete by the pushing force of the jack does not reach a predetermined value, and the hinge portion may hang down more than the designed value.

  Therefore, the present invention provides a drastic reinforcement method for the hinge part to almost completely reinforce the hinge part to form a reinforcing structure that makes the entire bridge continuous, and droops and damages exceeding the design value during construction and service. The purpose is to prevent deterioration and to ensure safe and comfortable driving performance.

  As a concrete means for solving the above-mentioned problems of the conventional example, the present invention is a method of reinforcing a hinge portion in a hinged girder bridge with a PC, up to a required length in the bridge axis direction on both sides over a predetermined range for placing concrete. After arranging the PC steel material and tension-fixing it to generate elastic tension in the PC steel material, a jack is installed at a required location within the above-mentioned predetermined range, and a compression force is applied to the bridge girder cross-sections on both sides of the range by pushing the jack. In addition to increasing the elastic tension of the PC steel material, the concrete is placed and hardened in the above range in a state where the jack is pushed out, and after the concrete is hardened, the jack is loosened and removed to remove both sides of the range. The compressive force applied to the cross section of the bridge girder and the elastic tension generated in the PC steel material are released and applied to the concrete within the above range as prestress. There is provided a hinge portion reinforcing method of PC girder bridge, characterized and.

  In the invention of the above-mentioned method for reinforcing a hinge portion, it is an additional requirement that steel frame steel materials are arranged in the bridge axial direction on both sides to the required length over the predetermined range and integrated with the bridge girder by additional concrete.

  Further, according to the present invention, there is provided a reinforcing structure of a hinge portion in a hinged girder bridge with a PC, in which a PC steel material is arranged to a required length in a bridge axial direction on both sides over a predetermined range where concrete is placed, and the PC steel material is tensioned and fixed. After the elastic tension is generated in the area, a jack is installed at a required position within the above-mentioned predetermined range, and a compression force is applied to the cross section of the bridge girder on both sides of the area by the pushing of the jack, and the elastic tension is further applied to the PC steel material. When the concrete is generated, concrete is placed in the above-mentioned range in a state where the jack is pushed out and hardened, and after the concrete is hardened, the jack is loosened and removed, and the compression force applied to the cross section of the bridge on both sides of the range and the PC. A PC girder characterized in that the elastic tension generated in the steel material is released and given to the concrete within the above range as prestress. There is provided a hinge reinforcement structure.

  In the invention of the above-mentioned hinge portion reinforcing structure, it is included as an additional requirement that steel frame steel materials are arranged in the bridge axial direction on both sides to the required length over the predetermined range and are integrated with the bridge girder by additional concrete.

The hinge part reinforcing method and the reinforcing structure according to the present invention have the following effects.
1. A predetermined range in which concrete including a hinge part is cast is set as a reinforcement range, and a PC steel material is first arranged in the bridge axial direction on both sides to a required length over the range and tension fixation is performed to generate elastic tension in the PC steel material. After that, with the jack installed and pushed out, that is, by operating the jack to extend the stroke and pushing the jack, a compressive force is applied to the cross section of the bridge girder on both sides of the (reinforcement) range, and elastic tension is applied to the PC steel material. When the concrete is further increased, the concrete is poured and hardened, and after the concrete hardens, the jack is loosened and removed, and the compressive force applied to the cross section of the bridge girder on both sides of the (reinforced) range and the elasticity generated in the PC steel material. By releasing the tension and applying it as prestress to the concrete within the (reinforcement) range, the range including the hinge part In addition, not only the pushing force of the jack but also the elastic tension of the PC steel material is generated from before the start of concrete pouring until it is hardened, and the elastic tension is a force that always tries to return. Since it acts on the concrete as a compressive force, it compensates for the loss of the pushing force of the jack due to drying shrinkage and creep deformation of the concrete after placing it, effectively suppressing the deformation of the concrete, loosening the jack after hardening the concrete, and releasing it. The compressive force of the jack and the elastic tension of the PC steel material can be applied to the concrete within the relevant (reinforcement) range by changing into a predetermined pre-stress, and it is possible to reliably prevent the sagging not only during construction but also during service. .
2. By arranging the PC steel material, a part of the prestress given to the concrete within the above (reinforcement) range will be generated in the PC steel material, and the capacity and number of jacks can be reduced, and the workability can be improved. The cost can be reduced.
3. The concrete within the range (reinforcement) is released as prestress by releasing the compressive force applied to the cross section of the bridge girders on both sides of the concrete range including the hinge part and the elastic tension generated in the PC steel material. By adding to the hinge, it is possible to suppress the initial cracking during construction of the relevant (reinforcement) area and the cracking during operation, prevent the deterioration of concrete due to the supply of water such as rainwater from the bridge surface, and to prevent the hinge. A tensile force is less likely to be generated in the reinforced area where the parts are continuous, and the effect of contributing to stress improvement is remarkable.
4. By arranging steel-framed steel material in the predetermined range including the hinge part, the cross-section proof stress of the predetermined range is greatly improved and the hinge part is in a continuous state, so it is possible to prevent damage during service. Produce the effect.
5. By making the hinge part continuous, noise and vibration generated during high-speed running of the vehicle can be reduced, so that an excellent effect of ensuring safe and comfortable running performance can be obtained.

A general box girder existing PC girder bridge to which the present invention is applied, wherein Fig. (A) shows an existing girder bridge having a hinge part at the center of the span, and Fig. (B) shows an intermediate part. It is the explanatory view which showed roughly the existing girder bridge which has two hinge parts in each. The 1st Embodiment of the reinforcing method which concerns on this invention is shown, Comprising: FIG.1 (c) is explanatory drawing which expanded and showed the point which is going to reinforce the hinge part which concerns on FIG.1 (a). FIG. 6D is a sectional view taken along the line AA of FIG. 1 shows the same embodiment, FIG. (E) is an explanatory view enlarged and showing a portion of the hinge portion according to FIG. 1 (a) to be reinforced and removed, and FIG. It is sectional drawing which follows the BB line of FIG. FIG. 12 shows the same embodiment, and FIG. 9 (g) is an explanatory view showing a situation of a reinforcement procedure I of the hinge portion related to FIG. 3 (e), and FIG. -It is sectional drawing which follows the C line. FIG. 7 shows the same embodiment, and FIG. (I) is an explanatory view showing the situation of hinge step reinforcement procedure II following FIG. 4 (g), and FIG. -It is sectional drawing which follows the D line. FIG. 5 shows the same embodiment, and FIG. 5 (k) is an explanatory view showing the situation of the hinge part reinforcement procedure III following FIG. 5 (i), and FIG. -It is sectional drawing which follows the E line. FIG. 7 shows the same embodiment, and FIG. 6 (m) is an explanatory view showing the situation of hinge step reinforcement procedure IV following FIG. 6 (k), and FIG. -It is sectional drawing which follows the F line. FIG. 4 is an explanatory view showing the same embodiment and showing the same hinge portion as that shown in FIG. 3 (e) in an enlarged manner by removing a portion to be reinforced, and before disposing a reinforcing bar on the hinge portion. In the same embodiment, FIG. 8 (a) is an explanatory view showing a state in which a reinforcing bar is arranged in a hinge portion to be reinforced, and FIG. 10 (p) is taken along line GG in FIG. FIG. The 2nd Embodiment of the reinforcing method which concerns on this invention is shown, (q) is explanatory drawing which expanded and showed the state which arrange | positioned the steel frame steel material in the hinge part which is going to reinforce, FIG. ) Is a sectional view taken along the line HH of FIG.

  The present invention will be described with reference to a plurality of examples according to the illustrated embodiments. First, the form of the hinge portion will be described with reference to FIGS. 1 (a) and 1 (b). For example, FIG. 1 (a) shows a PC bridge girder 2 erected on a bridge pier 1, wherein the bridge girder 2 is composed of the most common box girder and has a hinge part 3 in the center of the span. FIG. 2B shows that the bridge girder 2 has the hinge portions 3 in the middle thereof.

  When reinforcing the hinge part 3 of the PC bridge girder 2 as described above, in the case of the existing bridge girder, as shown in FIG. 2C, the replacement range of the bridge girders 2 on both sides including the hinge part 3 is set to a predetermined range 4. Cut and cut across. In this case, the divided cutting is performed, for example, in a state in which the portion to be divided and cut is supported by a temporary support column or the like, for example, by using a cutting means such as a wire saw, and the divided and cut portion is lifted as it is by a crane. Carry out.

  As shown in FIG. (D), the reinforcing bars 5 and the existing PC steel material (not shown) disposed in the PC bridge girder 2 are cut and the end faces are exposed at the cut surfaces on both sides of the bridge girder 2. There is. On the cut surface of the bridge girder 2, the concrete is scraped off by the water jet to the required thickness, and the reinforcing bar 5 and the PC steel material are projected to the required length, and the PC steel material is re-fixed by attaching a wedge type fixing tool to the tip thereof. . As for existing PC steel materials, until the existing fixing device is removed and re-fixed, the fixing state is achieved only by the attachment by the grout. Therefore, the existing grout state is confirmed, and the grout refilling work is performed as necessary. It may be done.

In the case of the new bridge girder 2, as shown in FIG. 3 (e), the central closing portion is shown as an example.
Also in this case, a predetermined space is provided between the ends of the supported bridge girders 2 with the predetermined range 4 including the hinge part 3 as a reinforcing range. That is, the connecting rebars 5 having a required length are exposed (projected) from the beginning on the end faces of the bridge girder 2 constructed by the projecting method on both sides. The reinforcing bar 5 arrangement at the end face of the bridge girder 2 is shown in FIG. Although not shown, a plurality of PC steel materials are arranged in the constructed bridge girder 2 and tension-fixed to the end surface of the bridge girder 2 using a fixing tool.
As above, the end of the bridge girder 2 is formed in substantially the same state (structure) in both existing and new construction.

Next, a procedure (process) of reinforcing the hinge portion 3 of the present invention will be described with reference to FIGS. 4 to 7.
[Procedure I]
As shown in FIGS. 4 (g) and 4 (h), in order to place concrete in the portion to be the hinge part 3, the bridge girder 2 constructed by the overhanging method from both sides leaving a predetermined range 4 A plurality of PC steel materials 6 are arranged in a direction up to a required length, and a fixing portion 7 is provided at an end portion of the bridge girder 2 to tension and fix the end portion of the PC steel material 6. In this case, the fixing portion 7 may be either a steel block or a concrete block, or may be an additional concrete.

  In the fixing section 7, for example, a required fixing tool 8 such as a nut is arranged to tension and fix the PC steel material 6. Although the PC steel material 6 is a PC steel rod in the drawing, it may be a PC cable made of a PC steel stranded wire. When using a PC steel rod, it is preferable to attach a steel pipe sheath to the outside of the PC steel rod to form an outer cable system. Further, when using a PC steel twisted wire, a PE steel twisted wire having a synthetic resin anticorrosive coating formed on the core wire and side wires of the PC steel twisted wire Rust-coated PC stranded wire, so-called unbonded double rust-proof PC stranded wire is used. In this case, it is possible to eliminate the need for a steel tube sheath outside the PC cable made of PC stranded wire. By elastically fixing the PC steel material 6 as shown in the figure, elastic tension (arrow a) can be generated in the PC steel material 6. At this stage, as a matter of course, new reinforcing bars (not shown) are welded and arranged between the reinforcing bars 5 projecting from the opposing end face of the bridge girder 2.

[Procedure II]
As shown in FIGS. 5 (i) and 5 (j), jacks 9 are installed at a plurality of locations (preferably four sides) within a predetermined range 4 of the facing surfaces at the ends of both bridge girders 2, and the jacks 9 are provided. It is possible to apply a compressive force (arrow b) to the cross-sections of the bridge girders 2 on both sides of the range and to further increase the elastic tension of the PC steel material 6 by the pushing action.

[Procedure III]
As shown in FIGS. 6 (k) and 6 (l), the jack 9 is used to push and spread the ends of both bridge girders 2 in the procedure II, and the hinge part 3 is attached to the portion of the two bridge girders 2. A required frame is formed corresponding to the shape of the end, and the jack 9 is surrounded (covered) so as to surround it, and concrete 10 is poured into the predetermined range 4 and hardened.

[Procedure IV]
As shown in FIGS. 7 (m) and (n), by loosening and removing the jack 9 after the cast concrete 10 hardens, the compressive force (arrow b) applied to the cross section of the bridge girders 2 on both sides and The elastic tension generated in the PC steel material 6 is released, and the released compressive force and elastic tension are applied as prestress to the concrete 10 within the predetermined range 4, so that range is reinforced. After that, the holes 10 formed by removing the enclosure (cover) of the jack 9 are filled with the hole-filling concrete 11, so that the cast concrete 10 becomes the hinge part 3.

In the above-mentioned embodiment, when a PC steel rod is used as the PC steel material 6 and a steel pipe sheath is attached to the outside, grout is filled in the steel pipe sheath to prevent the PC steel rod from rusting. It is desirable to fix the PC steel material by tension, but the tension force is suppressed within the elastic range of the steel material including the elastic tension increased to the PC steel material 6 by the extrusion of the jack 9, and the total is 0.7 Py or less. Yes (Py: PC steel yield strength). In short, if the elastic tension increased to PC steel by the extrusion of the jack 9 becomes 0.2 Py, the tension fixing force of the PC steel 6 is set to 0.5 Py or less first.
Further, when the PC steel rod 6 is arranged as the PC steel rod by the outer cable system, the PC steel rod hardly loosens, so that it is possible to perform only fixing without tension. When using a PC steel stranded wire, a slight tension force is applied to the extent that looseness is eliminated, and the tension is fixed as a tension force of, for example, 0.1 to 0.2 Py, so that the PC steel material 6 has an elastic range with a margin. It is preferable to deform the inside.

  Thus, by prestressing and forming the new concrete 10 that has been cast within the predetermined range 4 including the hinge portion 3, the deteriorated or damaged hinge portion is reinforced in a state of being continuous with the existing bridge girder. Not only is it possible to suppress the occurrence of initial cracks during construction, but it is also possible to prevent the occurrence of sagging in the closing portion (hinge portion) during construction, and to suppress the occurrence of cracks during use. The jack 9 used may be a hydraulic jack, a screw jack, or a bolt jack, and is not particularly limited. In addition, it is preferable to use expansive concrete as the concrete 10 that is placed within the predetermined range 4. That is, the pre-stress introduced by the jack 9 and the pre-stress are more effective in preventing the initial crack.

  In addition, in the said embodiment, the concrete Example which connects a reinforcing bar before pouring concrete is shown in FIGS. As shown in the figure, the existing connecting reinforcing bars 5 are preliminarily taken out from the girder end faces on both sides, and a new connecting reinforcing bar 12 is connected within the predetermined range 4 in the axial direction by, for example, enclosed welding, and necessary reinforcement is performed. A muscle (not shown), for example, a stirrup muscle is arranged. After that, concrete 10 is cast, and after the concrete is hardened, pre-stress is applied to the reinforced concrete, so that it becomes a stronger reinforcing portion than the conventional central closed portion made of RC.

Next, the second embodiment shown in FIG. 10 will be described.
In the second embodiment, in addition to the constituents according to the first embodiment, a structure for further increasing the strength of reinforcement of the hinge portion 3 is added.
That is, after placing the new concrete 10 within the predetermined range 4 described in the first embodiment and introducing the prestress to make the bridge girder 2 continuous, the inside of the box girder in the longitudinal direction of the bridge girder 2 A steel frame steel material 13 made of, for example, H-shaped steel having a required length extending beyond the hinge portion 3 to the inside of the bridge girders 2 on both sides is installed in the center portion, and end anchor plates 14 are provided at both ends of the steel frame steel material 13. Are integrally attached (attached) by welding or the like, and by additionally staking concrete 15 around the installed steel-frame steel material 13 to form the bridge girders 2 integrally, steel anchors are attached to the bridge girders 2 on both sides. The portion 16 is formed, and the connection strength is significantly improved. In this case, it is desirable to attach the stud bolts 17 to the flanges of the H-shaped steel forming the steel-steel material 13 to increase the adhesion to the additional concrete.

  As the steel frame material 13 used in this case, in consideration of the situation at the construction site, transportation and workability (handling), it is possible to use a long one (10 m or more) and a short one (5 m or less). You can do it. In the illustrated embodiment, a short steel frame steel material 13 is used, an end portion of the steel frame steel material 13 is provided with a predetermined length from the end surface of each bridge girder 2 on both sides, and the intermediate portions are connected in a butt state. The connecting steel frames 13a are placed in abutment with each other, and are connected through the gusset plate 18 using bolts to be integrated. In this way, by arranging the steel frames 13 both long and short so as to communicate with each other in the bridge girders 2 on both sides, by additionally staking concrete 15 around the steel frames 13 and forming it integrally with the bridge girders 2. The steel anchor portion 16 is formed.

  In any case, it is firmly fixed to the overfilled concrete 15 by the end anchor plate 14 provided at the end of the steel frame material 13, and the length of the anchor part 16 of the steel frame material 13 is increased as compared with the case of only the steel frame material 13. Since it can be shortened, construction becomes easy. Although illustration is omitted, as shown in FIGS. 8 to 9, reinforcing bars may be connected to the end faces of the bridge girders 2 facing each other to connect the reinforcing bars together.

  Further, after the steel-frame steel material 13 is connected, the concrete 10 is poured and hardened in the same manner as the procedure shown in FIGS. By loosening and removing the jack after hardening of the concrete, the compressive force applied to the cross section of the bridge girder 2 on both sides of the range and the elastic tension generated in the PC steel material 6 are released, and the released compressive force and elastic tension are prestressed. As a result, the concrete 10 within the range was reinforced and the predetermined range 4 was reinforced. In this way, when the prestress is introduced, the predetermined range 4 has a stronger structure by disposing the steel-framed steel material 13, and in particular, it is possible to reliably prevent the central closing portion including the hinge portion 3 from hanging down.

The present invention is not limited to the configurations according to the above-described embodiments, and various changes can be freely made without departing from the spirit of the present invention.
For example, in order to increase the strength of the reinforcement of the hinge portion 3, it is also possible to change the steel frame shown in the second embodiment to another reinforcing material, for example, a PC cable and to reinforce it by the outer cable method. Since the effect can be obtained, various configurations are included in the gist of the present invention as the reinforcing means of the hinge portion 3 to which the present invention is applied.

  A hinge part reinforcing method and a reinforcing structure of a PC girder bridge according to the present invention is a reinforcing method and a reinforcing structure of a hinge part 3 in a hinge girder bridge with a PC, which is a bridge shaft on both sides over a predetermined range 4 where concrete 10 is placed. After the PC steel material 6 is arranged to a required length in the direction and tension-fixed to generate elastic tension in the PC steel material, the jack 9 is installed at a required position within the above-mentioned predetermined range 4 and the jack 9 is extruded to remove the elastic force. A compressive force is applied to the bridge girder cross sections on both sides of the range, the elastic tension is further increased to the PC steel material, and concrete is placed and hardened in the above range while the jack 9 is pushed out, and after the concrete is hardened, the jack 9 By loosening and removing, the compressive force applied to the cross section of the bridge girders on both sides of the range and the elastic tension generated in the PC steel material are released and used as prestress. It is applied to the concrete 10 within the predetermined range 4, and the compressive force by the jack and the elastic tension of the PC steel material 6 are changed to a predetermined prestress and can be applied to the concrete 10 within the predetermined range 4 to be reinforced. It is possible to prevent drooping not only at the time of construction but also at the time of use, and by arranging the steel-framed steel material in the predetermined range including the hinge part, it is possible to significantly improve the cross-section proof strength of the predetermined range. Since it is possible, it can be used in a wide range in the repair work of this type bridge girder.

1 Bridge pier 2 Bridge girder 3 Hinge part 4 Predetermined range
5 Reinforcing bar for connection 6 PC steel 7 Fixing part 8 Fixing tool 9 Jack 10 Concrete 11 Filling concrete 12 New connection reinforcing bar 13 Steel frame steel 14 End anchor plate 15 Overcast concrete 16 Anchor part 17 Stud bolt 18 Gusset plate

As a concrete means for solving the above-mentioned problems of the conventional example, the present invention is a method for reinforcing a hinge portion in a hinged girder bridge with a PC, in which the bridge axial direction on both sides is extended over a predetermined range to be the hinge portion before concrete placing. After arranging the PC steel material to the required length and fixing the tension to generate elastic tension in the PC steel material, a jack is installed at a required position within the above predetermined range, and the bridge girders on both sides of the range are extruded by the jack. While applying a compressive force to the cross section and further increasing the elastic tension to the PC steel material, concrete is placed and hardened in the above range in a state where the jack is pushed out, and after the concrete is hardened, the jack is loosened and removed. The compressive force applied to the cross section of the bridge girders on both sides of the range and the elastic tension generated in the PC steel material are released to prestress the concrete within the above range. There is provided a hinge portion reinforcing method of PC girder bridge, characterized in that applied to.

Further, according to the present invention, in the reinforcing structure of the hinge part in the hinged girder bridge with PC, PC steel materials are arranged to a required length in the bridge axial direction on both sides over a predetermined range to become the hinge part before concrete placement, and the tension is fixed. After the elastic tension is generated in the PC steel material, a jack is installed at a required position within the above predetermined range, and a compression force is applied to the cross section of the bridge girder on both sides of the range by the pushing of the jack, and the PC steel material is Elastic tension is further generated, concrete is placed and hardened in the above range in a state where the jack is pushed out, and after the concrete is hardened, compression is given to the cross section of the bridge girder on both sides of the range by loosening and removing the jack. The force and the elastic tension generated in the PC steel material are released and applied as a prestress to the concrete within the above range. It is to provide a hinge reinforcement structure of the PC girder bridge to be.

Claims (4)

A method for reinforcing a hinge part in a hinged girder bridge with a PC,
PC steel materials are arranged in the axial direction on both sides to the required length over the specified range where concrete is placed, and after tension fixing to generate elastic tension in the PC steel materials, jacks are installed at the required locations within the specified range. Then, by pushing the jack, a compressive force is applied to the bridge girder cross sections on both sides of the range, and elastic tension is further increased to the PC steel material,
With the jack pushed out, concrete is poured into the above range and cured,
After loosening and removing the jack after the concrete has hardened, the compressive force applied to the cross section of the bridge girder on both sides of the range and the elastic tension generated in the PC steel material are released and given as prestress to the concrete within the range. A method of reinforcing the hinge part of a PC girder bridge characterized by: The method for reinforcing a hinge portion of a PC girder bridge according to claim 1, wherein steel frame steel materials are arranged on both sides in the axial direction of the bridge over the range up to a required length and are integrated with the bridge girder by additional concrete. Reinforcement structure of hinge part in hinge girder bridge with PC,
After the PC steel material is arranged in the bridge axial direction on both sides to the required length over the predetermined range where concrete is placed, and the PC steel material is tension-fixed and elastic tension is generated in the PC steel material, jacks are installed at the required locations within the above-mentioned predetermined range. By pushing the jack, a compressive force is applied to the bridge girder cross sections on both sides of the range, and elastic tension is further generated in the PC steel material,
Concrete is placed and cured in the above range with the jack pushed out,
By loosening and removing the jack after hardening of the concrete, the compressive force applied to the cross section of the bridge girder on both sides of the range and the elastic tension generated in the PC steel material are released and applied to the concrete within the range as prestress. Hinge reinforcement structure for PC girder bridge. The hinge part reinforcing structure for a PC girder bridge according to claim 3, wherein steel frame steel materials are arranged on both sides in the axial direction of the bridge over the range up to a required length and are integrated with the bridge girder by additional concrete.

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