CN111851251A - Box girder floor reinforcement structure and construction method thereof, box girder and box girder bridge - Google Patents

Abstract

The invention relates to a box girder bottom plate reinforcing structure which comprises an anchoring crossbeam and an external prestressed plate, wherein the length direction of the anchoring crossbeam is parallel to the transverse direction of a box girder, the bottom of the anchoring crossbeam is fixedly connected with the box girder bottom plate and/or two ends of the anchoring crossbeam are fixedly connected with two box girder web plates respectively, and the external prestressed plate is tensioned and anchored on the anchoring crossbeam through an anchor rope. In addition, the box girder adopting the box girder bottom plate reinforcing structure, a box girder bridge adopting the box girder and a construction method of the box girder bottom plate reinforcing structure are also provided. According to the invention, the anchoring cross beam is arranged in the box chamber, so that the structural integrity of the box girder and the transverse rigidity of the bottom plate of the box girder can be increased, and the anchoring cross beam is vertical to the bottom plate longitudinally, so that the occurrence and the expansion of longitudinal cracks of the bottom plate can be inhibited; by arranging the external prestressed plates and stretching and anchoring the external prestressed plates on the anchoring cross beam through the anchor cables, transverse pre-stress can be provided for the bottom plate, and the occurrence and the expansion of longitudinal cracks of the bottom plate can be reduced and restrained.

Description

Box girder floor reinforcement structure and construction method thereof, box girder and box girder bridge

technical field

The invention belongs to the technical field of civil engineering, and in particular relates to a box girder bottom reinforcement structure, a box girder using the box girder bottom reinforcement structure, a box girder bridge using the box girder, and a construction method of the above box girder bottom reinforcement structure.

Background technique

Large-span prestressed concrete variable-section box girder bridges are widely used bridge types, and continuous girder and continuous rigid-frame bridges are the most common. As shown in Figure 1-Figure 4, one of the long-span prestressed concrete variable-section box girder bridges with floor cables bent down has the following technical characteristics and accompanying common diseases of the floor:

(1) As shown in Figure 3 and Figure 4, the commonly used cross-section form of this variable-section box girder bridge is a single-box single-chamber cross-section. The elevation of the lower edge of 101 is arched, and this structural arrangement results in the elevation of the floor cable 103 also being arched, and the floor cable 103 is bent downward. Since the bottom cable 103 is tensioned and its two ends are anchored on the sawtooth block 104, the tensioned bottom cable 103 will inevitably generate downward radial force, and the downward radial force will have an unfavorable negative effect on the bridge, and it is easy to As a result, the bottom plate 101 is cracked.

(2) As shown in Figure 4, the floor cables 103 are generally arranged in a single layer in a row. When the span increases, the amount of the floor cables 103 increases sharply, and the hollowing rate on the horizontal line section of the center of the floor cables increases sharply. When the span increases, the downward radial force of the bottom plate cable 103 increases, while the effective cross-sectional area of the bearing decreases, which is more likely to cause the bottom plate 101 to crack or crack. At present, many continuous girder and continuous rigid frame bridges in the art have the problem of cracking along the bridge direction on the lower surface of the bottom plate 101 . Most bridges have a large hollowing rate from the mid-span section to the L/4 section, and the problem of cracking along the bridge direction on the lower surface of the bottom plate 101 is more serious.

(3) As shown in Figure 2 and Figure 3, when the span is increased, the amount of bottom cable 103 increases, and the bottom cable 103 located near the transverse centerline of the box girder needs to be flat bent to the junction of the web 102 and the bottom plate 101. If the force transmission route is shortened, the horizontal force and pulling force generated by the excessively large flat bends may also directly lead to the cracking of the bottom plate 101 . At present, there are many large-span continuous beams and continuous rigid-frame bridges in the art that have serious cracking problems along the bridge direction on the lower surface of the bottom plate 101 .

The cracking of the bottom plate 101 of the box girder reduces the overall stiffness of the bridge, causing the bridge to have too much downward deflection, which will cause the steel bars to corrode and affect the durability of the structure. The bottom plate 101 of the box girder is provided with bottom cables 103. When the bottom plate 101 is severely cracked, the durability of the bottom plate cables 103 will be affected, and the safety of the bridge may be further compromised.

Most of the existing methods to deal with the above-mentioned bridge floor cracks use measures such as pressing epoxy resin glue to seal the cracks in the floor, and sticking FRP cloth to strengthen them. These measures have little improvement on the problem of reducing the stiffness of the bridge after the floor cracks.

SUMMARY OF THE INVENTION

The present invention relates to a box girder floor reinforcement structure, a box girder using the box girder floor reinforcement structure, a box girder bridge using the box girder, and a construction method for the above box girder floor reinforcement structure, which can at least solve some defects of the prior art .

The invention relates to a box girder bottom reinforcement structure, comprising anchoring beams and external prestressed plates, the length direction of the anchoring beams is parallel to the transverse direction of the box girder, the bottom of the anchoring beams is fixedly connected with the box girder bottom plate and/or the The two ends of the anchoring beam are respectively fixedly connected with two box girder webs, and the external prestressed plate is anchored on the anchoring beam through anchor cable tensioning.

As one of the embodiments, two sets of reaction frames are provided on the external prestressed plate, and the two sets of reaction frames are respectively close to the two ends of the anchoring beam. The cable tensioning anchors are attached to the ends of the adjacent anchoring beams.

As one of the embodiments, a set of anchoring splints are arranged between each group of reaction force frames and the ends of the adjacent anchoring beams, the anchoring splints are fixedly installed on the external prestressing plate, and the reaction force frames are movably arranged on the external prestressing plate and abutting against the adjacent anchoring splint.

As one embodiment, the anchoring splint includes two splints arranged in sequence along the longitudinal direction of the box girder, the two splints are fixedly connected and at least one of the external prestressing plates is sandwiched between them.

As one of the embodiments, the board surfaces of each of the external prestressed boards are parallel to the vertical direction.

As one of the embodiments, the reaction force frame includes two frame bodies arranged in sequence along the longitudinal direction of the box girder, the two frame bodies are fixedly connected, and the two frame bodies are enclosed to form a penetration through which the external prestressed plate can pass through. The anchor cable is stretched on at least one of the frame bodies.

As one of the embodiments, one set of anchoring splints abuts against the ends of the adjacent anchoring beams, and the other set of anchoring splints has a lateral distance between the ends of the adjacent anchoring beams.

As one of the embodiments, a lead backing plate is sandwiched between the reaction force frame and the adjacent anchoring splints.

As one of the embodiments, the external prestressing plate is provided along the front side of the anchor beam and/or the rear side along the bridge, and the two ends of the anchor beam are provided with anchor boxes protruding toward the corresponding side, The anchor cables are stretched on two sets of anchor boxes on corresponding sides.

As one embodiment, a plurality of prestressed plate groups are arranged at intervals from top to bottom along the front side and/or the rear side of the anchor beam along the bridge, and each prestressed plate group includes at least one piece of external prestressing plate. stress plate.

As one of the embodiments, the anchor box is a steel anchor box, and the bottom of the box girder and/or the web of the box girder on the corresponding side is provided with reinforcement bars, and the anchor box is welded with the adjacent reinforcement bars. .

As one of the embodiments, the in vitro prestressed board is a CFRP board.

As one embodiment, the external prestressed board is accommodated in a GFRP isolation box, and the GFRP isolation box is fixed on the bottom plate of the box girder.

As one of the embodiments, the external prestressed plate, the anchor cable and the corresponding other anchoring devices are all pasted and coated with GFRP checkered cloth;

And/or, both the upper surface of the box girder bottom plate and the outer surface of the anchoring beam are pasted and coated with GFRP checkered cloth.

The invention also relates to a box girder, comprising a box girder bottom plate and two box girder webs, and at least one group of the above-mentioned box girder bottom plate reinforcement structures; when there are multiple groups of the box girder bottom plate reinforcement structures, each The anchoring beams are arranged at intervals along the longitudinal direction of the box girder.

As one of the embodiments, longitudinal beams are arranged in the box chamber, the longitudinal direction of the longitudinal beams is parallel to the longitudinal direction of the box beams, and the longitudinal beams are sequentially connected to the anchoring beams.

As one embodiment, there are at least two longitudinal beams, each longitudinal beam is connected to the bottom plate of the box girder, and the two longitudinal beams are respectively connected to the two box girder webs.

As one embodiment, the box girder includes a plurality of box girder segments, and at least some of the box girder segments are provided with floor cables and the box girder floor reinforcement structure.

As one embodiment, the bottom cable is anchored on the sawtooth block in the corresponding box girder segment, and the corresponding anchor beam is arranged just above the intersection of the upper slope of the sawtooth block and the bottom plate.

As one embodiment, the box girder is a variable-section box girder.

The present invention also relates to a box girder bridge, wherein at least part of the box girder adopts the above box girder.

The present invention also relates to the construction method of the above-mentioned box girder bottom plate reinforcement structure, including:

The anchor cable at one end of the anchor beam is stretched to the design tonnage and anchored, and then the anchor cable at the other end of the anchor beam is stretched to the design tonnage; among them, the surface dynamometer is pasted on the external prestressed plate, and the measurement is performed according to the surface dynamometer. The tension value of the symmetric synchronous control tension.

The present invention has at least the following beneficial effects:

The invention can increase the structural integrity of the box girder and the lateral rigidity of the bottom plate of the box girder by arranging the anchor beam in the box chamber. The anchor beam is vertical to the bottom plate, which is beneficial to suppress the occurrence and expansion of the longitudinal crack of the bottom plate; , and the external prestressed plate is anchored on the anchor beam through the anchor cable tension, which can provide lateral precompression stress to the bottom plate, and can reduce and restrain the occurrence and expansion of longitudinal cracks in the bottom plate.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a box girder bridge provided by an embodiment of the present invention;

Fig. 2 is the arrangement structure schematic diagram of the floor cable mentioned in the background technology;

Fig. 3 is the sectional view along A-A of Fig. 2;

Fig. 4 is the sectional view along B-B of Fig. 2;

FIG. 5 is a schematic structural diagram of a side view of a box girder provided by an embodiment of the present invention;

6 is a schematic top-view structural diagram of a box girder provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of the arrangement structure of the anchoring beam provided by the embodiment of the present invention;

8 is a schematic diagram of a box girder bottom plate reinforcement structure provided by an embodiment of the present invention;

9 is a schematic diagram of a tensile structure of an external prestressed plate for anchoring one end of a beam according to an embodiment of the present invention;

10 is a schematic diagram of a tensile structure of an external prestressed plate at the other end of the anchoring beam provided in an embodiment of the present invention;

11 is a schematic diagram of the installation process of the external prestressed plate, the anchoring splint, the reaction frame and the anchor cable provided by the embodiment of the present invention;

12 is a schematic diagram of an external prestressed plate, an anchoring splint, a reaction force frame and an anchor cable provided in an embodiment of the present invention after they are installed;

Figure 13 is a cross-sectional view along C-C of Figure 12;

in:

1, box girder, 2, bridge pier, 101, box girder bottom plate, 102, box girder web, 103, bottom cable, 104, sawtooth block, 105, anchor beam, 106, longitudinal beam, 107, anchor box, 108, external body Prestressed Plate, 109, Anchor Cable, 110, Anchor Plate, 111, Clip Anchor, 112, Extrusion Anchor, 113, Consolidated Steel Bar, 114, Reaction Frame, 1141, Anchor Pulling Hole, 115 , Anchoring splint, 116, Pulling clamping screw, 117, Lead pad.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

As shown in FIGS. 5-8 , an embodiment of the present invention provides a box girder floor reinforcement structure, including an anchoring beam 105 and an external prestressed plate 108. The length direction of the anchoring beam 105 is parallel to the transverse direction of the box girder. The anchoring beam 105 The bottom of the box girder is fixedly connected to the box girder bottom plate 101 and/or the two ends of the anchoring beam 105 are respectively connected to the two box girder webs 102. on the beam 105.

When the above box girder 1 is applied to a box girder bridge, the above-mentioned box girder transverse direction is also the transverse bridge direction. For a single-box-chamber box girder 1, it generally includes a box-girder bottom plate 101 and two box-girder webs 102; for a multi-box-chamber box girder 1, the box girder bottom plate 101 and the box girder webs to which the above-mentioned anchor beams 105 are fastened The plate 102 can be understood as the bottom plate and two webs corresponding to each chamber, so that the above-mentioned anchor beams 105 and external prestressing plates 108 can be arranged in each chamber.

The reinforcement structure provided in this embodiment is mainly used to reinforce the bottom plate. Therefore, the above-mentioned anchoring beam 105 is preferably connected to the box girder bottom plate 101, and it is more preferred that the bottom of the anchoring beam 105 is fixedly connected to the box girder bottom plate 101, and at the same time anchoring Both ends of the beam 105 are respectively fixed with the two box girder webs 102 to improve the reliability of the reinforced structure. For the setting of the anchoring beam 105, it can be connected with the box girder bottom plate 101 and/or the box girder web 102 by the method of planting reinforcement, and the connection structure is relatively reliable. The anchoring steel bars are arranged on the box girder bottom plate 101 and/or the box girder web 102 by the planting method, and the structural steel bars in the anchoring beam 105 are welded with the anchoring steel bars at the corresponding positions, so as to realize the anchoring beam 105 and the box girder bottom plate 101 and/or the anchoring steel bar. Or the fixed connection of the box girder web 102 .

The above-mentioned external prestressing plate 108 is preferably a CFRP plate (FRP is the English abbreviation of Fiber Reinforced Polymer, that is, fiber reinforced composite material; when the fiber is carbon fiber, it is CFRP). The tensile strength of the carbon fiber plate is about 3500MPa, and the value of 108 of the external prestressed plate can be about 2100MPa; the tensile force of the CFRP plate with a width of 50 mm and a thickness of 2 mm can reach 21 tons (tensile strength of 1860MPa and a diameter of 15.24). The tensile force of 75% of the strand value is also about 20 tons), so the use of CFRP board is reliable in work, and can ensure the stability and reliability of the above-mentioned box girder bottom plate reinforcement structure.

In the box girder floor reinforcement structure provided in this embodiment, the structural integrity of the box girder 1 and the lateral stiffness of the box girder floor 101 can be increased by arranging the anchor beams 105 in the box chamber. The occurrence and expansion of longitudinal cracks; by setting the external prestressing plate 108, and the external prestressing plate 108 is tensioned and anchored on the anchor beam 105 through the anchor cable 109, the lateral precompression stress can be provided to the bottom plate, which can be reduced and restrained Occurrence and propagation of longitudinal cracks in the floor.

Further optimizing the above-mentioned box girder bottom reinforcement structure, as shown in FIGS. 8-10 , the external prestressed plate 108 is provided with two sets of reaction force frames 114, and the two sets of reaction force frames 114 are respectively close to the two ends of the anchor beam 105, An anchor cable 109 is tensioned on each group of reaction frames 114 and the anchor cable 109 is tensioned and anchored on the end of the adjacent anchor beam 105 . The tension and anchorage of the external prestressed plate 108 is carried out through the reaction force frame 114, which is convenient for construction. The existing jack tensioning prestressing technology can be used, which can ensure the accuracy of the tensioning and prestressing, and can improve the external prestressing plate 108 and the anchorage. Tension anchoring effect of cable 109. Different from the conventional arrangement of the reaction force frame 114 , in this embodiment, the reaction force frame 114 is installed on the external prestressed plate 108 to facilitate the arrangement of the reaction force frame 114 in the limited space in the box.

Further preferably, as shown in FIGS. 9 and 10 , a group of anchoring splints 115 are arranged between each group of reaction frames 114 and the ends of the adjacent anchoring beams 105 , and the anchoring splints 115 are fixedly installed on the external prestressing plate. 108 , the reaction force frame 114 is movably arranged on the external prestressing plate 108 and abuts against the adjacent anchoring splints 115 . Based on this structure, the reaction force frame 114 and the anchoring splint 115 are used together as the tension component of the external prestressed plate 108. The reaction force frame 114 can be movably arranged, which is convenient for construction and prestressed tensioning operation, and can reduce the external prestressing force. Structural damage to plate 108. Wherein, optionally, as shown in FIG. 12 , a lead backing plate 117 is sandwiched between the reaction force frame 114 and the adjacent anchoring splint 115 to ensure the uniformity of the force of the anchoring splint 115, that is, to ensure the external prestressing plate 108 Uniformity of force.

Continuing the above structure, as shown in FIG. 13 , the anchoring splint 115 includes two splints arranged in sequence along the longitudinal direction of the box girder. The two splints are fixedly connected and at least one of the external prestressing plates 108 is sandwiched between them. . The plate surfaces of the above two plywoods are preferably parallel and vertical, and the plate surfaces of each external prestressed plate 108 are also preferably parallel to the vertical direction, that is, perpendicular to the longitudinal direction of the box girder, so as to facilitate arrangement. In one of the embodiments, as shown in FIG. 13 , the two splints can be fixed by a plurality of bolts/twisted clamping screws 116 to ensure that the external prestressing plate 108 between the two can be clamped. The bolt assembly method It is easy to disassemble and assemble, so it is convenient for construction. In an optional embodiment, as shown in FIG. 13 , two or more external prestressed plates 108 are used in the longitudinal direction of the box girder to fit and discharge in sequence, which can increase the tensile prestress, or, in other words, when the required When tension prestress is required, the tension prestress can be evenly distributed to each external prestressed plate 108, which can improve the stability and reliability of the above-mentioned bottom plate reinforcement structure.

Continuing the above structure, as shown in FIG. 13 , the reaction force frame 114 includes two frame bodies arranged in sequence along the longitudinal direction of the box girder. If the anchor cable 109 is stretched on at least one of the frame bodies, the effect of tensioning the anchor cable 109 on both frame bodies is obviously better, which can improve the force of the reaction frame 114 and the anchoring splint 115 Uniformity and tensioning stability, especially, in the structure that the anchoring splint 115 includes two splinting plates arranged in sequence along the longitudinal direction of the box girder, the two frame bodies are respectively abutted with the two splinting plates, the tensioning stability and the anchoring The force uniformity of the splint 115 is better; correspondingly, the above-mentioned frame body is correspondingly provided with an anchor pull hole 1141 for tensioning the anchor cable 109. The anchor pull hole 1141 is generally a round hole, and each frame body can be stretched more If there are several anchor cables 109, the number of anchor holes 1141 is set accordingly, and it is further preferred that a plurality of anchor cables 109 are stretched sequentially from top to bottom on each frame. It should be noted that the above-mentioned perforation holes can accommodate the corresponding external prestressed plates 108 to pass through. When two or more external prestressed plates 108 are sandwiched between the above-mentioned anchoring splints 115 along the longitudinal direction of the box girder, the above-mentioned The perforation hole should be able to allow the two or more external prestressing plates 108 to pass through together; at the same time, the perforation hole should prevent the anchoring splint 115 from passing through. For example, the plate surface of the stress plate 108 is parallel to the vertical. The height of the rectangular hole is greater than the height of the external prestressed plate 108 and less than the height of the anchoring splint 115. The width of the rectangular hole (that is, the dimension along the longitudinal direction of the box girder)≥ In the longitudinal direction of the box girder, the sum of the thicknesses of the external prestressing plates 108 sandwiched by the anchoring splint 115 is smaller than the width of the anchoring splint 115 . Likewise, the two frame bodies can be fixed by a plurality of bolts/pair-pulling clamping screws 116, and the bolt assembly method is convenient for disassembly and assembly, thus facilitating construction.

The above structure is further optimized, as shown in FIG. 6 , the external prestressing plate 108 is provided on the front side and/or the rear side of the anchor beam 105 along the bridge, and the two ends of the anchor beam 105 are convex toward the corresponding side. An anchor box 107 is provided outside, and the anchor cables 109 are stretched on the two sets of anchor boxes 107 on the corresponding side. Among them, it is preferable to set the above-mentioned external prestressed plates 108 on both the front side and the rear side of the anchor beam 105 along the bridge, so as to further increase the structural integrity of the box girder 1 and the lateral rigidity of the box girder bottom plate 101, it can be Increase the uniformity of the front and rear force of the anchoring beam 105; meanwhile, use the forward and/or rear space of the anchoring beam 105 along the bridge to facilitate the arrangement and construction of the external prestressing plate 108, the reaction frame 114, etc. The above-mentioned anchor box 107 is preferably a steel anchor box 107. When the anchor box 107 is only provided on one side of the anchor beam 105, the steel anchor box 107 is preferably embedded in the anchor beam 105; When the anchor boxes 107 are provided on both the front and rear sides, the steel anchor box 107 is preferably an integral structure and the front and rear ends respectively protrude out of the anchoring beam 105, so that the front and rear ends of the steel anchor box 107 are co-stressed and the anchorage is improved. The uniformity of the force on the steel anchor boxes 107 on both sides of the beam 105 . Understandably, the anchoring beam 105 has two sets of anchor boxes 107 along the front side of the bridge or along the rear side of the bridge, and the two sets of anchor boxes 107 on each side respectively protrude from both ends of the anchoring beam 105, The prestressed plates 108 are respectively tensioned and anchored to the two groups of anchor boxes 107 on the corresponding side through the anchor cables 109 .

For the above-mentioned setting of the anchor box 107, further preferably, the anchor box 107 is also connected with the box girder bottom plate 101 and/or the adjacent box girder web 102 to improve the working reliability of the anchor box 107. For example, for steel anchor boxes 107, reinforcement bars 113 can be planted on the box girder bottom plate 101 and the adjacent box girder webs 102, and the steel anchor boxes 107 are welded with the corresponding reinforcement bars 113; further, epoxy resin can be set at the bottom of the steel anchor boxes 107 The resin glue is bonded to the base plate. In addition, epoxy concrete is filled in the anchor box 107 to further improve the working reliability and service life of the anchor box 107; in one embodiment, the anchor cable 109 penetrates the anchor from the lateral/transverse bridge of the anchor box 107 to one side. Inside the box 107, the anchor box 107 is penetrated from the transverse/transverse bridge of the anchor box 107 to the other side and anchored. The epoxy concrete filled in the anchor box 107 can consolidate the anchor cable 109, which can improve the anchorage cable. 109 Stability and reliability of tensile structures.

To further optimize the above structure, as shown in Fig. 9-Fig. 12, a plurality of prestressed plate groups are arranged in sequence from top to bottom along the front side of the anchor beam 105 and/or the rear side along the bridge. The panel set includes at least one externally prestressed panel 108 . Based on the above structure, the structural integrity of the box girder 1 and the lateral stiffness of the box girder bottom plate 101 can be further increased. In an optional embodiment, each external prestressing plate 108 on each side is clamped by the same anchoring splint 115. Specifically, the anchoring splint 115 is correspondingly formed with a plurality of clamping holes in sequence from top to bottom, and the clamping holes are connected with the prestressing plate 115. The number of stress plate groups is the same and is arranged in a one-to-one correspondence, and each external prestressed plate 108 of each prestressed plate group is clamped in the corresponding clamping hole; for each prestressed plate group, when there are two or more When there are two or more external prestressed boards 108, it is preferable to adopt the method of successively attaching and discharging the external prestressing boards 108 along the longitudinal direction of the box girder. Similarly, each external prestressed plate 108 on each side is preferably stretched by the same reaction force frame 114, that is, the reaction force frame 114 is correspondingly provided with a plurality of through holes, and the through holes are the same as the number of prestressed plate groups. And in a one-to-one configuration, each external prestressing plate 108 of each prestressing plate group is pierced in the corresponding piercing hole. By using the same anchoring splint 115 and the reaction force frame 114 to tension and anchor each external prestressed plate 108 on the same side, it is not only convenient for construction, but also makes each external prestressed plate 108 on the same side cooperate with force, and at the same time increases the anchoring splint 115 and the force uniformity of the reaction force frame 114 .

In a preferred solution, as shown in FIG. 12, the anchor cable 109 is anchored on the reaction frame 114 through the clip anchor 111. For the case where there are multiple anchor cables 109 from top to bottom on each frame body, an integral The clip anchor 111 is used to anchor each anchor cable 109 on the frame body; a lead pad 117 can be arranged between the clip anchor 111 and the reaction force frame 114 to ensure the uniformity of the force of the reaction force frame 114 . 9-12, for the anchoring of the anchor cable 109 on the above-mentioned anchor box 107, the extrusion anchor 112 can be used; also the integral extrusion anchor 112 can be used for the multiple anchors on each frame. The anchor cable 109 is used for anchoring; the anchor plate 110 can be arranged between the squeeze anchor 112 and the anchor box 107 to ensure the uniformity of the force of the anchor box 107 . Obviously, other conventional anchoring methods of the anchor cable 109 are also suitable for this embodiment.

As a preferred solution of this embodiment, as shown in FIGS. 9 and 10 , one set of anchoring splints 115 abuts the ends of the adjacent anchoring beams 105 , and the other set of anchoring splints 115 and the ends of the adjacent anchoring beams 105 Has horizontal spacing. In the above structure in which the anchor boxes 107 are correspondingly arranged at the ends of the anchoring beams 105, one set of anchoring splints 115 abuts the adjacent anchor boxes 107, which can improve the stability and reliability of the anchoring structure; the other set of anchoring splints 115 and the adjacent anchor box 107 have a lateral distance. The above-mentioned lateral spacing should not be less than the set spacing, which is a critical spacing that meets the deformation requirements of the external prestressing plate 108, and is determined by those skilled in the art according to specific working conditions. Based on the setting of the above-mentioned lateral spacing, the effect of tensioning and anchoring of the external prestressed plate 108 and the working reliability can be ensured.

Continuing the above reinforcement structure, the external prestressed plate 108 is accommodated in a GFRP (fiber reinforced composite material in glass fiber, often called glass fiber reinforced plastic) isolation box, and the GFRP isolation box is fixed on the box girder bottom plate 101 . The above-mentioned GFRP isolation box can better protect the external prestressed plate 108 and prevent the external construction from affecting the external prestressed plate 108, so as to improve the service life of the external prestressed plate 108. This solution is especially suitable for the use of CFRP external prestressed plate 108. Happening. In this embodiment, the above-mentioned GFRP isolation box is a single-chamber box, which encloses the corresponding external prestressing plate 108 inside, and the anchor cables 109 pass out of the GFRP isolation box. In the above-mentioned structure in which a plurality of prestressed plate groups are arranged at intervals from top to bottom along the front side and/or the rear side of the anchor beam 105, each external prestressed plate 108 on each side can be accommodated in the same GFRP isolation box.

To further optimize the above reinforcement structure, the external prestressed plate 108, the anchor cable 109 and other corresponding anchoring devices are all pasted and coated with GFRP checkered cloth; and/or, the upper surface of the box girder bottom plate 101 and the anchoring beam 105 The outer surfaces are pasted and coated with GFRP checkered cloth. Specifically, each external prestressing plate 108 , each anchoring splint 115 , each reaction force frame 114 , bolts/screw rods and nuts for fastening the anchoring splints 115 , bolts and nuts for fastening the reaction force frame 114 , anchors The box 107 , the anchor cable 109 , the clip anchor 111 , the extruded anchor 112 , the lead backing plate 117 , etc. are all covered with GFRP checkered cloth, and the adhesive used can be, but not limited to, epoxy resin. The GFRP gingham cloth has a protective effect on each component, and at the same time strengthens the structure of each component, further improving the reinforcement effect on the bottom plate 101 of the box girder. Further preferably, when a crack occurs in the box girder bottom plate 101, after the cracks on the lower surface of the box girder bottom plate 101 are sealed by injection of epoxy resin glue, a layer of GFRP checkered cloth is pasted on the lower surface of the box girder bottom plate 101; The cloth has a complete waterproof effect on the box girder bottom plate 101, and at the same time strengthens the box girder bottom plate 101, which can restrain the further expansion of the lower surface of the box girder bottom plate 101 to the cracks along the bridge. In an optional solution, a layer of GFRP chopped strand mat can be pasted on both sides of the GFRP gingham to further optimize the structural strength and performance of the GFRP gingham. The adhesive can be but not limited to epoxy resin. .

To further optimize the above reinforcement structure, the working length section of the tension end of the anchor cable 109 is provided with a GFRP protective cover. The GFRP protective cover is filled with anti-rust butter, which can better protect the anchor cable 109 and prevent the anchor cable 109 from rusting. In the case where a plurality of anchor cables 109 are arranged in sequence in the vertical direction, the tensioned ends of each vertical row of anchor cables 109 can be arranged to be accommodated in the same GFRP protective cover. The GFRP protective cover can be a rectangular box structure, and is fixed on the adjacent tension members, for example, pasted and fixed on the reaction force frame 114 .

Embodiment 2

5 and 6, an embodiment of the present invention provides a box girder 1, which includes a box girder bottom plate 101 and two box girder webs 102, and also includes at least one set of the box girder bottom plate reinforcement structures provided in the first embodiment above; When there are multiple sets of reinforcement structures for the bottom plate of the box girder, the anchoring beams 105 are arranged at intervals along the longitudinal direction of the box girder.

The box girder 1 provided in this embodiment is preferably a concrete box girder 1; the box girder bottom plate 101 and the box girder web plate 102 are correspondingly reinforced concrete structures.

The box girder 1 provided in this embodiment is preferably a box girder 1 with floor cables 103 arranged. The box girder bottom plate reinforcement structure. The arrangement structure of the bottom cable 103 is a conventional technology in the art, and will not be repeated here; the damage to the box girder bottom plate 101 that may be caused by the arrangement of the bottom plate cable 103 can be avoided and solved by the above-mentioned box girder bottom plate reinforcement structure. In particular, when the above-mentioned box girder 1 is a variable-section box girder 1, based on the above-mentioned box girder bottom plate reinforcement structure, the box girder bottom plate caused by the arrangement of the bottom plate cables 103 in the variable-section box girder 1 can also be better solved. 101 Disease. In one of the embodiments, as shown in FIGS. 5 and 6 , the floor cables 103 are anchored on the sawtooth blocks 104 in the corresponding box girder segments, and are arranged just above the intersection of the upslope surface of the sawtooth blocks 104 with the bottom plate Corresponding anchoring beam 105; for the variable section box girder 1, the anchoring beam 105 is also set at the front end of the corresponding box girder segment, where the front end of the box girder segment is the pier 2 away from the adjacent pier of the box girder segment One end of the top; the anchoring beam 105 is arranged in the area where the bottom plate of the corresponding box girder segment is prone to disease, which obviously has a better reinforcement effect for the box girder bottom plate 101 .

The above-mentioned box girder bottom plate reinforcement structure may be formed when the box girder 1 is prepared, or may be a structural modification of the existing box girder 1 , that is, a later structure formed in the existing box girder 1 .

The above scheme is further optimized, as shown in Fig. 6-Fig. 10, a longitudinal beam 106 is also arranged in the box chamber, and the longitudinal direction of the longitudinal beam 106 is parallel to the longitudinal direction of the box beam. 105 is connected as a whole, which improves the cooperative force bearing capacity of each anchoring beam 105, which is more favorable for suppressing the occurrence and development of longitudinal cracks in the box girder bottom plate 101. Further preferably, there are at least two longitudinal beams 106, each longitudinal beam 106 is connected with the box girder bottom plate 101, and two of the longitudinal beams 106 are respectively connected with two box girder webs 102, so that each longitudinal beam 106 connects the box girder The girder bottom plate 101 , the box girder web 102 and the anchoring beams 105 are connected as a whole, which can not only significantly improve the structural integrity of the box girder 1 , but also increase the longitudinal rigidity of the box girder bottom plate 101 . As shown in FIGS. 7-10 , for the above-mentioned structure provided with anchor boxes 107, each anchor box 107 is preferably embedded in the corresponding longitudinal beam 106, and the anchor box 107 may not be connected with the adjacent box girder webs 102, but through The longitudinal beams 106 realize indirect connection with the adjacent box girder webs 102 .

Embodiment 3

As shown in FIG. 1 , an embodiment of the present invention provides a box girder bridge, and at least part of the box girder 1 adopts the box girder 1 provided in the second embodiment.

Embodiment 4

The embodiment of the present invention relates to the construction method of the box girder bottom plate reinforcement structure provided by the above-mentioned first embodiment, including:

The anchor cable 109 at one end of the anchor beam 105 is stretched to the design tonnage and anchored, and then the anchor cable 109 at the other end of the anchor beam 105 is tensioned to the design tonnage; wherein, the surface dynamometer is pasted on the external prestressing plate 108, according to The tension value measured by the surface dynamometer is controlled and tensioned symmetrically and synchronously to achieve the required external prestress tensioning and anchoring effect, so as to ensure the reliable reinforcement of the box girder bottom plate 101 .

This implementation method can adopt the single-cable jack tensioning prestressing technology, which is more convenient for construction; the accuracy of the tensioning force can be improved by pasting the surface dynamometer on the external prestressing plate 108, and the surface dynamometer and the oil of the jack The triple control of the gauge oil pressure and the elongation of the external prestressing plate 108 ensures that the tensioning prestress is symmetrical, synchronized and accurate.

Specifically, the above construction method includes:

Step 1: Install the anchor box 107, the anchor cable 109 and the pouring anchor beam 105 on the box girder bottom plate 101, wherein the anchor beam 105 is fixedly connected with the box girder bottom plate 101 and/or the two ends of the anchor beam 105 are respectively connected with two box beams. The web 102 is fixedly connected, and the anchor box 107 protrudes toward the front side and/or the rear side of the bridge along the bridge of the anchoring beam 105 ; one end of the anchor cable 109 is installed on the anchor box 107 .

Step 2: Install the external prestressing plate 108 , the reaction force frame 114 , the anchoring splint 115 and the clip anchor 111 of the anchor cable 109 to the design position in the box girder 1 . A surface dynamometer is attached to the external prestressed plate 108 .

Step 3: Tensing the anchor cable 109 at one end of the anchor beam 105 to the design tonnage for anchoring, and then tensioning the anchor cable 109 at the other end of the anchor beam 105 to the design tonnage. Wherein, symmetrical synchronous tension control is performed according to the tensile force value measured by the surface dynamometer on the in vitro prestressed plate 108; in one embodiment, the surface dynamometer is pasted on both sides of the in vitro prestressed plate 108 During the tensioning process, the difference between the tensile force values of a pair of surface dynamometers on the external prestressed plates 108 is less than ±2%, and the maximum difference between the tensile force values of the external prestressed plates 108 is less than ±5%. Preferably, the deviation of the final tensile force value of each surface dynamometer is less than ±2%; the deviation between the sum of the final tensile force value of each surface dynamometer and the design total tensile force is less than ±1.5%. Further, by measuring the elongation of the external prestressed plate 108, combined with the control method of the above-mentioned surface dynamometer, a reliable and effective tension control of the externally prestressed plate 108 is achieved.

Further preferably, when the box girder 1 is further provided with a longitudinal beam 106, the casting operation of the longitudinal beam 106 is also performed in step 1.

It can be understood that the above method can be echoed to the box girder bottom reinforcement structure provided in the first embodiment and the box girder 1 provided in the second embodiment, that is, the box girder bottom reinforcement structure provided in the first embodiment and the above embodiment. 2. The corresponding structural contents in the provided box girder 1 are also applicable to this embodiment, for example, the relative connection structure between the anchoring beam 105, the external prestressing plate 108, the anchoring splint 115, the reaction force frame 114, etc. are not described here. Repeat.

To further refine the above method, in step 1, for the installation of the anchor box 107, reinforcing bars 113 can be formed by planting reinforcement on the box girder bottom plate 101 and/or the box girder web 102 on the corresponding side. When the anchor box 107 is installed, Welded with these consolidation bars 113. At the same time, in step 1, the joint surface between the anchoring beam 105 and the box girder bottom plate 101, the joint surface between the anchoring beam 105 and the box girder web 102, the longitudinal beam 106 and the box girder bottom plate 101 can be completed accordingly. The joint surface between the longitudinal beams 106 and the box girder web 102 is roughened and cleaned; reinforcement can be planted on the box girder bottom plate 101 and/or the box girder web 102 on the corresponding side to form anchoring steel bars, The anchoring beam 105 is then poured after the structural steel bars of the anchoring beam 105 and the corresponding anchoring steel bars are welded; the longitudinal beam 106 may also adopt a corresponding construction method, which will not be repeated here. For the structure filled with epoxy concrete in the anchor box 107, this step 1 can be completed together.

Further preferably, in step 1, after the restored concrete in the steel anchor box 107, the concrete of the anchoring beam 105 and the concrete of the longitudinal beam 106 reach the strength, the upper surface of the box girder bottom plate 101, the outer wall of the anchoring beam 105, the outer wall of the longitudinal beam 106 A layer of GFRP plaid is pasted on the surface. Optionally, after the cracks on the lower surface of the bottom plate are sealed with epoxy resin glue, a layer of GFRP checkered cloth is pasted on the bottom surface of the bottom plate.

To further refine the above method, after the tensioning of the anchor cable 109 is completed, the surface of the external prestressed plate 108 and the surface of all the iron components of the relevant anchoring system are pasted with an outsourced GFRP checkered cloth. Optionally, install a rust-proof cover provided at the working length section of the tension end of the anchor cable 109 .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (22)

1. The utility model provides a case roof beam bottom plate reinforced structure which characterized in that: including anchor crossbeam and external prestressing force board, the length direction of anchor crossbeam is horizontal in the case roof beam, the bottom of anchor crossbeam links firmly with the case roof beam bottom plate and/or the both ends of anchor crossbeam link firmly with two case roof beam webs respectively, external prestressing force board passes through anchor rope stretch-draw anchor and is in on the anchor crossbeam.

2. A box girder bottom plate reinforcing structure according to claim 1, wherein: and two groups of reaction frames are arranged on the external prestressed plate, the two groups of reaction frames are respectively close to two ends of the anchoring cross beam, an anchor cable is stretched on each group of reaction frames, and the anchor cable is stretched and anchored on the end part of the adjacent anchoring cross beam.

3. A box girder bottom plate reinforcing structure according to claim 2, wherein: and a group of anchoring clamping plates are arranged between each group of reaction frames and the end part of the adjacent anchoring cross beam, the anchoring clamping plates are fixedly arranged on the external prestressed plate, and the reaction frames are movably arranged on the external prestressed plate and are tightly propped against the adjacent anchoring clamping plates.

4. A box girder floor reinforcement structure according to claim 3, wherein: the anchoring clamping plate comprises two clamping plates which are sequentially arranged along the longitudinal direction of the box girder, and the two clamping plates are fixedly connected and at least one external prestressed plate is clamped between the two clamping plates.

5. A box girder floor reinforcement structure according to claim 4, wherein: the plate surface of each external prestressed plate is parallel to the vertical direction.

6. A box girder floor reinforcement structure according to claim 3, wherein: the reaction frame comprises two frame bodies which are sequentially arranged along the longitudinal direction of the box girder, the two frame bodies are fixedly connected and surrounded to form a through hole for accommodating the external prestressed plate to pass through, and the anchor cable is stretched on at least one of the frame bodies.

7. A box girder floor reinforcement structure according to claim 3, wherein: one group of the anchoring clamping plates is abutted with the end part of the adjacent anchoring beam, and the other group of the anchoring clamping plates has a transverse distance with the end part of the adjacent anchoring beam.

8. A box girder floor reinforcement structure according to claim 3, wherein: and a lead base plate is clamped between the reaction frame and the adjacent anchoring clamping plate.

9. A box girder floor reinforcement structure according to any one of claims 1 to 8, wherein: the front side of the anchoring beam is arranged along the bridge and/or the rear side of the anchoring beam is arranged along the bridge, the external prestressed plates are arranged at the two ends of the anchoring beam and protrude towards the corresponding side to form anchor boxes, and the anchor cables are stretched and pulled on the two groups of anchor boxes at the corresponding side.

10. A box girder floor reinforcement structure according to claim 9, wherein: a plurality of prestress plate groups are sequentially arranged at intervals from top to bottom along the front side and/or the rear side of the anchoring beam along the bridge, and each prestress plate group comprises at least one external prestress plate.

11. A box girder floor reinforcement structure according to claim 9, wherein: the anchor box is a steel anchor box, consolidation reinforcing steel bars are arranged on a box girder bottom plate and/or a box girder web plate on the corresponding side, and the anchor box is welded with the adjacent consolidation reinforcing steel bars.

12. A box girder bottom plate reinforcing structure according to claim 1, wherein: the external prestressed plate is a CFRP plate.

13. A box beam floor reinforcement structure as defined in claim 12, wherein: the external prestressed plate is contained in a GFRP isolation box, and the GFRP isolation box is fixed on a box girder bottom plate.

14. A box girder bottom plate reinforcing structure according to claim 1, wherein: the external prestressed plate, the anchor cable and other corresponding anchoring devices are all stuck and coated with GFRP check cloth;

and/or the upper surface of the box girder bottom plate and the outer surface of the anchoring beam are both pasted and coated with GFRP (glass fiber reinforced plastics) check cloth.

15. The utility model provides a box girder, includes box girder bottom plate and two box girder webs, its characterized in that: further comprising at least one set of box girder floor reinforcement structures according to any one of claims 1 to 14; when the box girder bottom plate reinforcing structures are in multiple groups, the anchoring cross beams are sequentially arranged at intervals along the longitudinal direction of the box girder.

16. A box beam as defined in claim 15 wherein: and a longitudinal beam is arranged in the box chamber, the length direction of the longitudinal beam is parallel to the longitudinal direction of the box beam, and the longitudinal beam is sequentially connected with the anchoring cross beams.

17. A box beam as defined in claim 16 wherein: the number of the longitudinal beams is at least two, each longitudinal beam is connected with the box girder bottom plate, and the two longitudinal beams are respectively connected with the two box girder webs.

18. A box beam as defined in claim 15 wherein: the box girder comprises a plurality of box girder sections, and at least part of the box girder sections are internally provided with bottom plate cables and the box girder bottom plate reinforcing structure.

19. A box beam according to claim 18 wherein: the bottom plate cable is anchored on a sawtooth block in a corresponding box girder segment, and a corresponding anchoring cross beam is arranged right above the intersection of the upper slope surface of the sawtooth block and the bottom plate.

20. A box beam as defined in claim 19 wherein: the box girder is a variable cross-section box girder.

21. A box girder bridge which characterized in that: at least part of the box girder is the box girder as claimed in any one of claims 15-20.

22. A construction method of a box girder floor reinforcement structure according to any one of claims 1 to 14, comprising:

tensioning the anchor cable at one end of the anchoring beam to a designed tonnage and anchoring, and then tensioning the anchor cable at the other end of the anchoring beam to the designed tonnage; wherein, a surface dynamometer is pasted on the external prestressed plate, and the symmetrical synchronous control tensioning is carried out according to the tension value measured by the surface dynamometer.

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