JP6325286B2 - Bridge reinforcement structure and bridge reinforcement method - Google Patents

Description

  The present invention relates to a bridge reinforcing structure and a bridge reinforcing method for improving fatigue durability of a reinforced concrete floor slab by preventing deformation of the bridge due to a ring load applied to the slab concrete slab.

  When a vehicle such as a truck passes over a reinforced concrete floor slab, a ring load acts on the bridge from the vehicle, and the bridge is bent. For example, when the floor slab is thin, when a ring load acts on the floor slab as shown in FIG. 8, a force acts locally on the flange of the steel girder supported under the floor slab, The floor slab bends as the flange and web are deformed and the spacing between the PQs is increased. In this case, in addition to the flange, the steel girder web may be curved and deformed. The reinforced concrete slab of a bridge repeats this deformation many times each time the vehicle passes, resulting in fatigue and reduced durability. For this reason, the reinforced concrete slab of the bridge has to suppress the bending due to the wheel load and improve the fatigue durability.

  As a reinforcing structure for a bridge composed of a slab floor slab and a plurality of steel girders that support the slab concrete, as a result of intensive studies in the past, for example, disclosed techniques of Patent Document 1, Patent Document 2 and Patent Document 3 have been proposed. ing. For example, the disclosed technique of Patent Document 1 shows a method for reinforcing a road floor slab in which a belt-like continuous fiber sheet is attached to a floor slab lower surface with an adhesive in a lattice shape.

  In the disclosed technique of Patent Document 2, a horizontal girder that is spaced apart from a floor slab is passed between steel girders, and a plurality of support portions are provided between the floor slab and the cross girder. By connecting the upper end of this support part to the floor slab and connecting the lower end of the support part to the cross beam, the span between the steel girders is shortened, and the bending moment caused by the bending of the floor slab is reduced, so that the floor slab is stabilized. Fig. 4 shows a supported reinforcement structure.

  The disclosed technique of Patent Document 3 shows a reinforcing structure in which a construction beam is bridged between bridge piers and a jack is interposed between the construction beam and the floor slab to give a pushing force to the floor slab.

JP 2005-29953 A JP 2001-336116 A JP 2003-171913 A

  By the way, in the disclosed technique of Patent Document 1, there are cases where the epoxy resin bonded by the action of repeated loads deteriorates and the strip-like continuous fiber sheet is peeled off from the floor slab. The effect is lost, and the fatigue durability of the floor slab is significantly reduced.

  Moreover, in the disclosure technique of patent document 2 and patent document 3, in order to take the reaction force for suppressing the bending moment of a floor slab by using a support part and a jack, respectively, It is necessary to ensure rigidity of the erected beam to which the jack is attached. For this reason, in the disclosed technologies of Patent Document 2 and Patent Document 3, the size of each member is increased and the number of parts is increased, so that the construction becomes complicated, and the construction cost increases accordingly.

  In addition, a vertical stiffener is attached to the steel girders of the bridge. This vertical stiffener is mainly for suppressing deformation of the web of the steel girder. Since the interval at which the slab is attached in the direction of the bridge axis is large, it is not possible to suppress the bending of the floor slab and the deformation of the flange of the steel girder.

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to reinforce the bridge that can suppress bending of the bridge due to the ring load applied to the floor slab of reinforced concrete. It is to provide a method for reinforcing a structure and a bridge.

In the first invention of the present application, a bridge comprising a reinforced concrete floor slab and a plurality of steel girders on which the reinforced concrete floor slab is placed and supported is bent by a wheel load of a vehicle traveling on the reinforced concrete floor slab. The reinforcing structure of the bridge to suppress, wherein the steel girder has an upper flange, a lower flange, and a web connecting them, and the vertical member that reduces the downward deflection of the reinforced concrete floor slab, It is provided perpendicular to the longitudinal direction of the steel girders at a predetermined interval along the longitudinal direction of the steel girders at a shorter interval than the vertical stiffener that prevents local buckling of the web. The flat stiffener has a flat plate substantially parallel to the vertical stiffener, and the plate thickness surface of the flat plate is in perpendicular contact with the lower surface of the upper flange.

A second invention of the present application is characterized in that, in the first invention, a tie material for preventing an interval between adjacent steel girders from spreading is bridged between the vertical members.

The third invention of the present application is characterized in that, in the second invention, the tie material has at least one of a carbon fiber rod, a PC steel rod, and a shaped steel.

According to a fourth invention of the present application, in the second or third invention, the tie material is provided with a hinge that allows the adjacent steel girders to move up and down separately.

According to a fifth aspect of the present invention, a bridge including a reinforced concrete floor slab and a plurality of steel girders on which the reinforced concrete floor slab is placed and supported is bent by a wheel load of a vehicle traveling on the reinforced concrete floor slab. A method of reinforcing a bridge, wherein the steel girder has an upper flange, a lower flange, and a web connecting them, and is shorter than a vertical stiffener that prevents local buckling of the web. , provided vertically upright to reduce the downward deflection of the reinforced concrete slab in the longitudinal direction of the steel girder with a predetermined interval along the longitudinal direction of the steel girder, the uprights, the vertical auxiliary A flat plate substantially parallel to the rigid member is provided, and the plate thickness surface of the flat plate is brought into contact with the lower surface of the upper flange perpendicularly.

6th invention of this application WHEREIN: In 5th invention, the tie material which suppresses that the space | interval of the said adjacent steel girders spreads is provided between the said perpendicular | vertical materials.

A seventh invention of the present application is characterized in that, in the sixth invention, a hinge is provided that allows the steel girders adjacent to the tie material to move up and down separately.

According to the first to seventh inventions, the vertical member is attached to the web of the steel girder at an interval shorter than the interval of the vertical stiffener, so that the reinforced concrete slab can be prevented from being bent due to the wheel load. . In addition, according to the first to seventh inventions, the vertical member has a flat plate and has a simple structure in which the plate thickness surface of the flat plate is in contact with the upper flange. The deformation of the upper flange of the steel girder can be suppressed.

According to the 2nd , 3rd , 4th , 6th and 7th inventions, the slab is provided with a tie material that prevents the space between adjacent steel girders from widening, so that prestress is introduced into the floor slab. As such, the tensile force acting on the floor slab is reduced and the bending of the floor slab can be suppressed, and the fatigue durability of the floor slab is improved.

Since the 1st- 7th invention is a simple structure which attaches a vertical material or attaches a tie material, the workability as a reinforcement structure of a bridge improves. Moreover, the construction quality at the time of reinforcement can be secured by this simple structure. Furthermore, it becomes possible to visually confirm the progress of deterioration after reinforcement over the entire surface. For this reason, in addition to workability, economy is also improved.

It is a perspective view of a 1st embodiment of a bridge reinforcement structure to which the present invention is applied. (A) is a front view of 1st Embodiment of the reinforcement structure of the bridge to which this invention is applied, (b) is the top view. It is the front view which attached the vertical material to the steel girder. It is a front view of 2nd Embodiment of the reinforcement structure of the bridge to which this invention is applied. It is a front view of 3rd Embodiment of the reinforcement structure of the bridge to which this invention is applied. It is a vertical sectional view of a 4th embodiment of a bridge reinforcement structure to which the present invention is applied. It is the figure which showed the numerical analysis graph which uses nonlinear finite element analysis COM3D based on the elastic-plastic / fracture attack model and a distributed crack following the floor slab before and behind reinforcement. (A) is a front view showing a state before a wheel load is applied to a conventional bridge, and (b) is a front view showing a state of deformation of a floor slab and a steel girder after the wheel load is applied to the bridge. FIG.

  Hereinafter, a bridge reinforcing structure and a bridge reinforcing method according to an embodiment of the present invention will be described in detail with reference to the drawings.

First embodiment

  In the bridge reinforcement structure, the structure of the bridge reinforcement structure 1a in which a vertical member is brought into contact with the lower surface of the upper flange of the steel beam of the bridge will be described in detail with reference to FIGS.

  As shown in FIG. 1, a bridge reinforcing structure 1a includes a bridge steel girder 2a, a reinforced concrete floor slab 3a mounted on the bridge steel girder 2a, and a vertical member 4a attached to the bridge steel girder 2a. Prepare.

  The steel girder 2a of the bridge is made of, for example, a steel material having an existing H-shaped cross section, and mainly assumes a steel girder of an existing bridge. The steel girder 2a of the bridge includes a steel girder 20a having a web 21a, an upper flange 22a fixed to the upper end of the web 21a at a substantially right angle, and a lower flange 23a fixed to the lower end of the web at a substantially right angle, and a bridge shaft. And a plurality of vertical stiffeners 5a attached to the web 21a, the upper flange 22a, and the lower flange 23a at intervals in the direction. Here, the web 21a, the upper flange 22a, and the lower flange 23a are substantially rectangular flat plates, respectively, and the upper end of the web 21a and the lower surface of the upper flange 22a, and the lower end of the web 21a and the upper surface of the lower flange 23a are respectively welded or the like. It is fixed and extended in the direction of the bridge axis.

  The vertical stiffener 5a is, for example, rectangular in cross section, and has a predetermined rigidity at appropriate intervals in the bridge axis direction so that the web 21a can maintain the proof strength until the yield of the upper flange 22a and the lower flange 23a. And it is a member for preventing local buckling.

  The reinforced concrete floor slab 3a is a member that directly receives a wheel load from the vehicle. The reinforced concrete floor slab 3a plays a role of transmitting the wheel load to the steel girder 20a without causing any deformation that would hinder the running performance of the vehicle when subjected to the wheel load.

  The vertical member 4a, for example, has two flat plates fixed to each other in a L-shaped cross section in a plan view by welding or the like, and is attached to the web at an interval shorter than the interval in the bridge axis direction of the vertical stiffener 5a. The flat plate 41a and the flat plate 42a that is in contact with the lower surface of the upper flange 22a perpendicularly. The flat plate 41a has a through hole (not shown), and a bolt 411a is inserted through the through hole. The front end of the bolt 411a is inserted into a through hole (not shown) provided in the web 21a and is inserted into a through hole (not shown) of a flat plate 41a similarly provided on the opposite side of the web 21a, from the opposite side of the web 21a. The flat plate 41a is screwed and fixed by a nut 412a so as to sandwich the web 21a. Also, as shown in FIG. 3, the corner where the upper flange 22a and the web 21a are in contact is welded, so that the corner of the flat plate 42a corresponding to the corner is partially cut away.

  Next, a method for reinforcing a steel girder of a bridge to which the present invention is applied will be described in detail with reference to FIGS.

  The flat plate 41a of the vertical member 4a is attached to the web 21a at an interval shorter than the interval in the bridge axis direction of the vertical stiffener 5a attached to the steel beam 2a of the existing bridge, and the flat plate 42a is attached to the lower surface of the upper flange 22a. This is completed by bringing the plate thickness surfaces into contact with each other vertically.

  Next, the manner in which the force of the vertical member 4a acts on the force acting on the steel beam 2a of the bridge when a wheel load of a vehicle or the like acts from the reinforced concrete floor slab 3a in the first embodiment will be described with reference to FIG. To do.

  When the wheel load acts downward from the upper end of the reinforced concrete slab 3a, the force acts downward on the upper flange 22a of the steel beam 2a of the bridge. At this time, since the vertical member 4a is in contact with the lower surface of the upper flange 22a, the upper flange 22a receives a reaction force upward from the vertical member 4a. As a result, the reaction force balances with the wheel load, thereby preventing the upper flange 22a from being deformed. Moreover, since it is a simple structure in which the plate | board thickness surface of the said flat plate 42a is contact | abutted to the upper flange 22a of the steel beam 20a, a deformation | transformation of the upper flange 22a can be suppressed by simple construction.

Second embodiment

  Next, in the reinforcing structure of the bridge, refer to FIG. 4 for the structure of the reinforcing structure 1b of the bridge in which a vertical member is brought into contact with the lower surface of the upper flange of the steel beam of the bridge and a tie material is attached between the vertical members. However, it explains in detail.

  As shown in FIG. 4, the bridge reinforcement structure 1b includes a bridge steel girder 2b, a reinforced concrete floor slab 3b mounted on the bridge steel girder 2b, a vertical member 4b attached to the bridge steel girder 2b, A tie material 6b attached to two opposing vertical members 4b between the two steel girders 2b of the bridge.

  Here, the web 21b, the upper flange 22b, the lower flange 23b, the vertical stiffener 5b, the reinforced concrete floor slab 3b, and the flat plate 41b and the flat plate 42b of the vertical member 4b in the bridge steel girder 2b are the same as the reinforcement structure 1a of the bridge. It is the same.

  The tie material 6b shown in FIG. 4 is assumed to be, for example, a carbon fiber rod or a PC steel rod. The tie material 6b is not limited thereto, and a carbon fiber rod or a PC steel rod may be used as a raw material, and a turnbuckle may be attached to the approximate center of the steel beams 2b of the two bridges. The tie material 6b shown in FIG. 4 is screwed and fixed by a nut 422b from the front side by inserting a bolt 421b from the back side of the flat plate 42b into a through hole (not shown) of the flat plate 42b of the vertical material 4b. Although the tie material 6b shown in FIG. 4 is provided between the flat plates 41b of the vertical material 4b between the adjacent steel girders 20b, the vertical material 4b and the vertical stiffening are not limited to this. It may be provided between the material 5b or between the vertical stiffeners 5b.

  Next, a method for reinforcing a bridge in the bridge reinforcing structure 1b to which the present invention is applied will be described in detail with reference to FIG.

  The flat plate 41b of the vertical member 4b is attached to the web 21b at an interval shorter than the interval in the bridge axis direction of the vertical stiffener 5b attached to the steel beam 2b of the existing bridge, and the flat plate 42b is attached to the lower surface of the upper flange 22b. The plate thickness surfaces of the plates are brought into contact with each other vertically. Next, it completes by attaching the tie material 6b between the vertical members 4b in the steel girders 2b of the adjacent bridges.

  Next, how the force of the vertical member 4b acts on the force acting on the steel beam 2b of the bridge when a wheel load of a vehicle or the like acts from the reinforced concrete floor slab 3b in the second embodiment will be described with reference to FIG. To do.

  As shown in FIG. 4, when the wheel load acts downward from the upper end of the reinforced concrete slab 3b, the force acts downward on the upper flange 22b of the steel beam 2b of the bridge. At this time, since the vertical member 4b is in contact with the lower surface of the upper flange 22b, a reaction force is received upward from the vertical member 4b to the upper flange 22b. Thereby, this reaction force is balanced with the wheel load, so that the deformation of the upper flange 22b can be prevented. In addition, the presence of the tie material 6b allows the tie material to pass a tensile force between the steel girders to resist the tensile force of the floor slab, and as if prestressing was introduced to the floor slab. The force is reduced and the bending of the floor slab can be suppressed, and the fatigue durability of the floor slab is improved.

Third embodiment

  Next, as a bridge reinforcing structure according to the third embodiment, in the bridge reinforcing structure of the second embodiment, a bridge in which angle steel is attached instead of a carbon fiber rod and a PC steel bar as a tie material between vertical members. The structure of the reinforcing structure 1b ′ will be described in detail with reference to FIG.

  Here, the web 21b ′, the upper flange 22b ′, the lower flange 23b ′, the vertical stiffener 5b ′, the reinforced concrete floor slab 3b ′, the flat plate 41b ′ and the flat plate 42b ′ of the vertical member 4b ′ are formed in the steel girder 2b ′ of the bridge. The configuration is the same as that of the bridge reinforcing structure 1a.

  The tie material 6b 'shown in FIG. 5 is screwed and fixed by a nut 422b' from the front side by inserting a bolt 421b 'from the back side of the flat plate 42b' into a through hole (not shown) of the flat plate 42b 'of the vertical material 4b'. The tie material 6b 'shown in FIG. 5 may be provided between the vertical material 4b' and the vertical stiffener 5b 'or between the vertical stiffeners 5b' similarly to the tie material 6b. The bridge reinforcing structure 1b 'has the same function and effect as the bridge reinforcing structure 1b and its reinforcing method.

  The vertical member 4a shown in FIG. 3, the vertical member 4b and tie member 6b shown in FIG. 4, and the vertical member 4b ′ and tie member 6b ′ shown in FIG. Workability is improved. Moreover, since all this invention is a simple structure, the construction quality at the time of the reinforcement of the steel girder of a bridge can be ensured. Further, the present invention makes it possible to visually confirm the progress of deterioration after reinforcing the steel girders of the bridge from the outside over the entire surface. For this reason, this invention improves economical efficiency in addition to workability.

Fourth embodiment

  Next, a bridge reinforcing structure 1c according to the fourth embodiment will be described with reference to FIG. The bridge reinforcement structure 1c according to the fourth embodiment is different from the bridge reinforcement structure 1b 'according to the third embodiment mainly in that a hinge is provided on an angle steel of a tie material.

  The bridge 1 shown in FIG. 6 includes a reinforced concrete floor slab 3c and a plurality of bridge steel girders 2c that support the reinforced concrete floor slab 3c. Further, studs or the like (not shown) protrude from the upper surface of the bridge steel girder 2c, and the reinforced concrete floor slab 3c and the bridge steel girder 2c are integrated into a bridge. The same applies to the bridge reinforcing structures 1a, 1b, 1b 'according to the first to third embodiments.

  The steel girder 2c of the bridge includes a web 21c made of a rectangular flat plate having a vertically long cross section, an upper flange 22c made of a rectangular plate having a vertically long cross section connected to the upper and lower ends of the web 21c at a substantially right angle, and a bottom. And an H-shaped steel (or I-shaped steel) having an H-shaped cross section having a flange 23c. Then, a plurality of bridge steel girders 2c are arranged side by side at a predetermined interval with the bridge axis direction as the longitudinal direction, thereby constituting the bridge 1. The steel girder 2c of this bridge mainly assumes the steel girder of the existing bridge.

  Further, a vertical stiffener 5c for preventing local buckling of the web 21c is attached to the bridge steel girder 2c by a method such as welding at intervals along the longitudinal direction of the bridge steel girder 2c. The vertical stiffener 5c is a rectangular flat plate with a predetermined cross section having a predetermined rigidity, and the bridge steel girder at a predetermined interval at which the web 21c can maintain the proof strength until the yield of the upper flange 22c and the lower flange 23c. It arrange | positions at predetermined intervals along the longitudinal direction of 2c.

  The vertical stiffener 5c is different from the vertical stiffeners 5a, 5b, 5b ′ of the first to third embodiments described above, but abuts against the upper flange 22c and the web 21c. It is a point which is not in contact with 23c. This is to improve workability, improve drainage and improve durability, etc. If the above-mentioned vertical stiffener can also prevent local buckling of the web, There is no need to abut.

  The reinforced concrete floor slab 3c is a member that directly receives the wheel load from the vehicle. When the wheel load is received, the reinforced concrete floor slab 3c has a function of transmitting the wheel load to the steel girder 2c of the bridge without causing a deformation that impedes the traveling performance of the vehicle. Plays.

  Furthermore, the bridge steel girder 2c is provided with a plurality of vertical members 4c that reduce downward deflection of the reinforced concrete floor slab 3c. The vertical member 4c is made of angle steel having an L-shaped cross section in which the flat plate 41c and the flat plate 42c are vertically joined along the longitudinal direction. The steel beam of the bridge is shorter than the interval of the vertical stiffener 5c. It is attached to the web 21c at a predetermined interval along the longitudinal direction 2c so as to be perpendicular to the longitudinal direction of the bridge steel beam 2c. One flat plate 42c of the vertical member 4c is attached in contact with the lower surface of the upper flange 22c perpendicularly.

  A through hole (not shown) is formed in the flat plate 41c, and a bolt B is inserted into the through hole. The front end of the bolt B is inserted into a through hole (not shown) provided in the web 21c and is inserted into a through hole (not shown) in a flat plate 41c similarly provided on the opposite side of the web 21c, from the opposite side of the web 21c. The flat plate 41c is screwed and fixed with a nut N so as to sandwich the web 21c. That is, the vertical member 4c is fixed to the web 21c by bolt joining (friction joining) with the bolt B and the nut N.

  In addition, a tie material 6c is attached between the flat plates 42c of the vertical members 4c attached between the steel beams 2c of the adjacent bridges so as to prevent the interval between the steel beams 2c of the adjacent bridges from expanding. Yes. This tie material 6c is different from the above-described tie material 6b 'in that a hinge 60 is provided near the center of the tie material 6c in the longitudinal direction.

This hinge 60 connects the left and right symmetrical one side member 61 and the other side member 62 so as to be rotatable in the vertical plane at the center in the longitudinal direction of the tie material 6c, and the steel girder 2c of two adjacent bridges. It has a function of absorbing the difference in the amount of subsidence in the vertical direction of 2c. The hinge 60 may be a three-dimensional hinge limited to a two-dimensional hinge that rotates in a vertical plane. In short, the hinge 60 only needs to allow the steel beams 2c of the adjacent bridges to move up and down separately.
However, as the hinge 60, the two-dimensional hinge is cheaper and more economical and practical.

  Next, a method for reinforcing a bridge according to the fourth embodiment will be described. First, the vertical members 4c are attached to the web 21a by bolting at a distance shorter than the interval of the vertical stiffeners 5c attached to the existing bridge steel girders 2c, perpendicular to the longitudinal direction of the bridge steel girders 2c. At this time, it attaches so that the upper end surface used as the edge of the flat plate 42c of the vertical member 4c may contact | abut with the upper flange 22c.

  Then, the tie material 6c having the hinge 60 at the center is bridged between the flat plates 42c of the vertical members 4c attached between the steel beams 2c of the adjacent bridges, and both ends thereof are respectively formed on the flat plates 42c. Join the bolts.

  According to the bridge reinforcing structure 1c and the bridge 1 reinforcing method according to the fourth embodiment as described above, since the vertical member 4c is provided, the deformation of the upper flange 22c is suppressed, and the lower part of the reinforced concrete floor slab 3c. Can be reduced.

  Moreover, since the tie material 6c which connects these perpendicular | vertical materials 4c is attached, it can suppress that the space | interval of the steel girder 2c of an adjacent bridge spreads, prevents the bridge 1 from bending, and is durable. Can be improved.

  In addition, since the tie material 6c is provided with a hinge 60 at the center, even if the steel girders 2c and 2c of the adjacent bridges are sunk unevenly (non-settled) due to wheel loads or the like, the amount of settlement This difference can be absorbed by the hinge 60, and the tie material 6c can resist the force that widens the distance between the steel beams 2c and 2c of the bridge. Therefore, the bridge 1 can be further prevented from being bent and the durability can be improved.

  Next, the results of numerical analysis using the nonlinear finite element analysis COM3D based on the elasto-plastic fracture constitutive law and the distributed crack model will be described with reference to FIG.

  This numerical analysis uses a high-cycle path-dependent constitutive model that can reproduce the fatigue damage behavior of reinforced concrete due to cyclic loading. This model consists of three constitutive laws representing tensile, compression, and shear transfer at the crack surface of reinforced concrete, and expresses the behavior associated with multidirectional cracks. Fatigue damage due to repeated loading can be explained by the time-dependent increment of plastic deformation and stiffness reduction. Tests have confirmed that the time-deformation history obtained by the logarithmic direct integration method using these constitutive laws reproduces the fatigue damage process of a structure subjected to repeated loads well.

The model used for the numerical analysis shown in FIG. 7 uses an 8-node isoparametric element for the finite element, and the upper slab, the reinforcing steel plate and the upper flange of the steel girder are solid elements, and the steel girder web, lower flange and The cross beam and reinforcement are modeled with plate elements. The compressive strength of concrete is 25.5 MPa and the tensile strength is 1.8 MPa. Table 1 shows the analysis cases. Here, Case1 is a case of non-reinforcement and is a standard for other cases. Case 2 is a case reinforced by bonding a steel plate to the bottom of the floor slab, and is carried out in order to compare the present invention with a conventional reinforcing method. The reinforcing steel plate is t = 4.5 mm and is bonded to the bottom of the floor slab with an epoxy resin. The adhesive is expressed as a joining element between the floor slab and the reinforcing steel plate, and the initial rigidity is 1.5 × 10 ³ N / mm ² which is the lower limit of the material standard value of the epoxy resin. Yes. Case 3 is a case in which angle steel is used as a reinforcing material and t = 9 mm is used as a vertical material for attachment to a steel girder, and is assumed to be the basic method of the present invention. The vertical members and steel girders behave as a unit, but they are structured to allow rotation in the out-of-plane direction. Case 4 is obtained by eliminating the angle steel from the vertical material of Case 3, and is only the vertical material attached to the steel girder. The load in the moving load test is such that a wheel load of 180 kN is applied directly to the nodal point, and is 16 points of 450 mm in the bridge axis direction and 300 mm in the direction perpendicular to the bridge axis. The loading speed is 1 Hz in the fixed point fatigue test and 4 km / hr in the moving loading test. The drying shrinkage is given as 328μ for convenience. The number of contraction days is 30 days until the loading start date.

  In the analysis result shown in FIG. 7, the horizontal axis represents the number of times, and the vertical axis represents the deflection at the center of the floor slab. Here, the fatigue life is assumed to be 10 mm when the deflection starts to increase rapidly. In the cases in which any of Cases 2 to 4 is reinforced, the initial deflection is reduced to about half in all three cases, and the fatigue life is extended. In the case where Case 1 is not reinforced, the life is reached after about 200,000 times, whereas in cases where Cases 2 to 4 are reinforced, the fatigue life is 10 times or more.

  In the case of the steel plate adhesion reinforcement of Case 2, since the reinforcing steel plate is not extended to the haunch part as the reinforcement of only the lower surface of the floor slab, the floor slab on the steel beam is damaged and the fatigue life is reached. However, this is different from the actual reinforcement method, so care must be taken when calculating the fatigue life of the slab. On the other hand, both Cases 3 and 4 show a reinforcing effect more than the adhesion of steel plates, and the result is that the fatigue life of the floor slab greatly exceeds 2 million times, which is one standard, and the present invention is a steel girder due to the ring load applied to the floor slab of the bridge. It was shown that this is a bridge reinforcing structure suitable for preventing the deformation of the bridge.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the above-mentioned embodiment is only what showed the example of implementation in implementing this invention, These are the technical scope of this invention by these. Should not be interpreted in a limited way.

  In particular, the vertical stiffeners 5a, 5b, 5b ′ and 5c are intended to prevent local buckling of the web, and do not necessarily contact the upper and lower flanges. I can't.

  Further, although the vertical members 4a, 4b, 4b 'and 4c have been described by exemplifying those which are bolted to the web, they may be attached by welding or the like. However, the bolt joint is preferable in that quality control is easy and the steel girder as a base material is not affected.

  Furthermore, the tie materials 6b, 6b ′, 6c are not limited to the material of the members and the like as long as the steel girders can withstand the tensile force that the steel girders want to spread, and are not limited to the bolt joints exemplified for the joining methods at both ends. Any bonded portion that can withstand the tensile force described above may be used. Moreover, although what illustrated joining the both ends of the longitudinal direction of tie material 6b, 6b ', 6c to the perpendicular | vertical material 4b, 4b', 4c was demonstrated, the end or both ends of these tie materials 6b, 6b ', 6c were demonstrated. May be joined to any of a vertical member, a vertical stiffener, a web, an upper flange, and a lower flange. That is, as long as the tie materials 6b, 6b ', 6c are used to connect adjacent steel girders, they may be joined anywhere or other members may be interposed.

1 Bridges 1a, 1b, 1b ', 1c Bridge reinforcement structures 2a, 2b, 2b', 2c Steel girders for bridges (steel girders)
3a, 3b, 3b ', 3c Reinforced concrete floor slabs 4a, 4b, 4b', 4c Vertical members 5a, 5b, 5b ', 5c Vertical stiffeners 6b, 6b', 6c Tie materials 20a, 20b, 20b 'Steel girders 21a , 21b, 21b ′, 21c Web 22a, 22b, 22b ′, 22c Upper flange 23a, 23b, 23b ′, 23c Lower flange 41a, 41b, 41b ′, 41c, 42a, 42b, 42b ′, 42c Flat plate 411a, 411b, 411b ', 421a, 421b, 421b', B bolts 412a, 412b, 412b ', 422a, 422b, 422b', N nut

Claims (7)

A bridge reinforcing structure that suppresses bending of a bridge including a reinforced concrete floor slab and a plurality of steel girders on which the reinforced concrete floor slab is placed and supported by a wheel load of a vehicle traveling on the reinforced concrete floor slab. There,
The steel girder has an upper flange, a lower flange, and a web connecting them,
The vertical member that reduces the downward deflection of the reinforced concrete floor slab is shorter than the vertical stiffener that prevents local buckling of the web, with a predetermined interval along the longitudinal direction of the steel girder. It is provided perpendicular to the longitudinal direction of the steel girder ,
The vertical member has a flat plate substantially parallel to the vertical stiffener, and the plate thickness surface of the flat plate is in contact with the lower surface of the upper flange perpendicularly. . The bridge reinforcing structure according to claim 1, wherein a tie material for preventing an interval between adjacent steel girders from extending is bridged between the vertical members. The bridge reinforcement structure according to claim 2 , wherein the tie material includes at least one of a carbon fiber rod, a PC steel rod, and a shape steel. The bridge reinforcing structure according to claim 2 or 3 , wherein the tie material is provided with a hinge that allows the adjacent steel girders to move up and down separately. A bridge reinforcing method that suppresses bending of a bridge including a reinforced concrete slab and a plurality of steel girders on which the reinforced concrete slab is placed and supported by a wheel load of a vehicle traveling on the reinforced concrete slab. There,
The steel girder has an upper flange, a lower flange, and a web connecting them,
A vertical member that reduces the downward deflection of the reinforced concrete slab at a shorter interval than a vertical stiffener that prevents local buckling of the web, with a predetermined interval along the longitudinal direction of the steel girder. Provided perpendicular to the longitudinal direction of the beam ,
The method of reinforcing a bridge, wherein the vertical member has a flat plate substantially parallel to the vertical stiffener, and a plate thickness surface of the flat plate is brought into contact with a lower surface of the upper flange perpendicularly. The method for reinforcing a bridge according to claim 5 , wherein a tie material that inhibits an interval between adjacent steel girders from spreading is provided between the vertical members. The bridge reinforcing method according to claim 6 , further comprising: providing a hinge that allows the steel girders adjacent to the tie material to move up and down separately.

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