Active reinforcing method for solving stress of single hollow slab

Abstract

The invention belongs to the field of bridge engineering, and particularly relates to an active reinforcing method for solving stress of a hollow slab veneer, which comprises the following steps: determining the mounting position of a fish-bellied corrugated steel web beam, and polishing the bottom surface of the hollow slab beam and the side surface of a side plate at the mounting position; holes are drilled in the side faces of the hollow slab beam side plates, and screws of the embedded steel bar anchor bolts are installed; epoxy mortar is smeared on a top plate of the fish-bellied corrugated steel web beam, and the fish-bellied corrugated steel web beam is fixed through embedded steel bar anchor bolts on the two sides of a hollow plate beam side plate; and the prestressed carbon plate is tensioned on the bottom plate of the fish-bellied corrugated steel web to a set load, so that the prestressed carbon plate is completely attached to the bottom plate of the corrugated steel web beam, and the prestressed carbon plate is fixed and tensioned. Part of horizontal prestress generated by tensioning the prestress carbon plate is converted into upward supporting force through the fish-bellied corrugated steel web beams, the generated single plate deformation problem is actively adjusted and recovered, meanwhile, it is guaranteed that the problem that the hollow plate single plate is stressed when vehicles run on the bridge floor is avoided, and the use efficiency of prestress is greatly improved.

Description

Technical Field

[0001] The invention belongs to the field of bridge engineering, and in particular relates to an active reinforcement method for solving the stress of a hollow slab. Background Art

[0002] Prefabricated hollow slabs have become the preferred solution for small and medium span bridges at home and abroad due to their advantages such as convenient construction, small building height and economical cost. They are widely used and numerous. Most of the hollow slab beam bridges built in the early days used small tongue-and-groove hinged joints. This structure has its own defects. Coupled with the effect of long-term automobile loads, the hinged joints of this type of hollow slab beam bridges are easily damaged, and the lateral connection between the main beams fails, which causes the main beam single plate to be stressed, cracking, severe deflection and other diseases, which seriously affect driving safety and pose a threat to the normal operation of road traffic. The treatment of prefabricated hollow slab bridges in the "single plate stress" state has become a difficult problem for highway maintenance departments.

[0003] In view of the stress disease of the single slab of the hollow slab beam bridge, applying transverse prestressing outside the hollow slab is a reinforcement method. The principle of this method is to increase the compressive stress of the bottom slab concrete of the hollow slab by arranging transverse prestressing tendons at the bottom of the hollow slab, thereby balancing the tensile stress of the bottom slab caused by the bending moment, enhancing the transverse connection performance between the main beams of the hollow slab, and changing the hinged structure system to a rigid structure system, thereby achieving the purpose of improving the overall transverse distribution of the bridge load and enhancing the overall stress performance of the structure. Some foreign scholars have conducted parametric research on the transverse prestressing reinforcement of prefabricated hollow slab bridges with different sizes of prestressing and different arrangements, and have achieved some research results. It is found that the use of tensioning transverse prestressing for single slab stress repair can enhance the overall transverse performance of the bridge, but for the case where the hinge joint is severely damaged or the single slab is severely stressed, the construction is difficult and the reinforcement effect is limited. It is difficult to fundamentally solve the "single slab stress" problem by applying prestressing alone in the horizontal direction.

[0004] Therefore, how to provide an active reinforcement method for solving the stress of hollow slabs with high reinforcement efficiency and easy construction, and provide a reference for the reinforcement design of similar projects, has become a problem that technical personnel in this field need to consider. Summary of the invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention discloses an active reinforcement method for solving the stress of a hollow slab. The present invention can not only improve the problem of low prestressing efficiency caused by small eccentricity during traditional horizontal tensioning of transverse prestress, but also utilize fish-belly corrugated steel web beams to convert part of the horizontal prestress into an upward supporting force, which is easy to construct and greatly improves the use efficiency of prestressing. The present invention specifically discloses the following technical solutions:

[0006] An active reinforcement method for solving the stress of a hollow slab includes the following construction steps:

[0007] S01. Determine the installation position of the fish-belly corrugated steel web beam, and grind the bottom surface of the hollow slab beam and the side surface of the side plate at the installation position;

[0008] S02. Drill holes on the side of the hollow slab beam and install the screws of the anchor bolts;

[0009] S03. Apply epoxy mortar on the top plate of the fish-belly corrugated steel web beam, install the fish-belly corrugated steel web beam, and fix the fish-belly corrugated steel web beam through anchor bolts on both sides of the hollow slab beam side plate;

[0010] S04. Tension the prestressed carbon plate on the bottom plate of the fish-belly corrugated steel web to a set load, so that the prestressed carbon plate is completely fitted with the bottom plate of the corrugated steel web beam, and the tensioned prestressed carbon plate is fixed.

[0011] Furthermore, the fish-bellied corrugated steel web beam described in step S01 is transversely installed at the bottom of the 1 / 2 length section beam and the bottom of the 1 / 4 length section beam in the middle of the span of the hollow slab bridge.

[0012] Furthermore, the top plate of the fish-bellied corrugated steel web beam in step S01 is a rectangular surface, and the cross-section of the fish-bellied corrugated steel web beam is an arc shape, with the highest beam height at the bridge axis and the smallest beam height near the two sides.

[0013] Furthermore, in step S01, anchoring steel plates are arranged at both side beam ends of the fish-belly corrugated steel web beam, and the anchoring steel plates are connected to the outer web of the side plates of the hollow slab beam by embedded anchor bolts.

[0014] Furthermore, it also includes a stiffening plate, which is welded to the outside of the anchoring steel plate to avoid out-of-plane deformation of the anchoring steel plate.

[0015] Furthermore, it also includes a prestressed anchoring device, which is welded to the stiffening plate.

[0016] Furthermore, before installing the fish-belly corrugated steel web beam in step S03, high-durability rubber strips with a thickness of 5 mm are pasted on both sides above the top plate of the fish-belly corrugated steel web beam along the length direction, and the epoxy mortar is applied to the inside of the rubber strips of the top plate. After the fish-belly corrugated steel web beam is installed in place, it is tightened upward.

[0017] Furthermore, the prestressed carbon plate in step S04 is anchored on the prestressed anchoring devices at the anchoring areas at both ends of the fish-belly corrugated steel web beam.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention uses the upward radial force generated by the prestressed carbon plate on the bottom plate of the fish-belly corrugated steel web beam to reset the hollow slab beam with damaged hinge joints. Similarly, the upward radial force generated by the active tensioning of the prestressed carbon plate can also ensure that the hollow slab single plate will not be stressed when the bridge deck vehicle is driving. It can not only improve the problem of low prestressing efficiency caused by small eccentricity during traditional horizontal tensioning of transverse prestress, but also use the fish-belly corrugated steel web beam to convert part of the horizontal prestress into an upward supporting force, which greatly improves the use efficiency of the prestress and has a good application prospect.

[0020] 2. Compared with the method of applying horizontal transverse prestress at the bottom of the hollow slab beam to press the hollow slabs together, the present invention has the advantage of being able to actively reset the hollow slab that has undergone uneven deformation. At the same time, the tensioned prestress and the fish-bellied corrugated steel web beam can also cooperate with the hollow slab to bear force, forming a combined force system in the transverse direction of the hollow slab bridge;

[0021] 3. The present invention adopts a fish-belly corrugated steel web beam to replace the traditional flat steel plate, and uses the spring effect of the corrugated steel web beam to reduce the in-plane stiffness of the web, so that it can bend and deform freely with the top plate and the bottom plate of the corrugated steel web beam, ensuring that when the steel beam bends upward, the efficiency of prestressing will not be reduced due to the high in-plane compressive stiffness of the fish-belly beam web. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the cross-sectional arrangement of the hollow slab beam reinforcement of the present invention;

[0023] Figure 2 It is a schematic diagram of the local structure of the anchorage area of ​​the fish-belly corrugated steel web beam of the present invention;

[0024] Figure 3 It is a schematic diagram of sticking a rubber strip on the top plate of the fish-belly corrugated steel web beam of the present invention.

[0025] Among them, 1. hollow slab beam; 2. fish-belly corrugated steel web beam; 3. prestressed carbon plate; 4. prestressed anchor device; 5. stiffening plate; 6. embedded steel anchor bolt; 7. anchor steel plate; 8. rubber strip; 9. top plate; 10. bottom plate. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] See attached Figure 1-3This embodiment discloses an active reinforcement method for solving the stress of a hollow slab, including the following construction steps:

[0029] S01. Determine the installation position of the fish-belly corrugated steel web beam 2, and install the fish-belly corrugated steel web beam 2 transversely at the bottom of the 1 / 2 length section beam and the bottom of the 1 / 4 length section beam in the middle of the hollow slab bridge. The top plate 9 of the fish-belly corrugated steel web beam 2 in this embodiment is a rectangular surface, and the cross-section of the fish-belly corrugated steel web beam 2 is an arc shape. The beam height is the highest at the bridge axis and the smallest near the two sides. Grind the bottom surface of the hollow slab beam 1 and the side surface of the side plate at the installation position;

[0030] S02. Drill holes on the side of the hollow slab beam 1 and install the screws of the anchor bolts 6. The number of anchor bolts 6 is designed by force calculation;

[0031] S03. Before installing the fish-belly corrugated steel web beam 2, in order to ensure that the upper flange of the fish-belly corrugated steel web beam 2 is tightly fitted with the lower edge of the hollow slab beam 1, a 5mm thick high-durability rubber strip 8 is pasted on both sides above the top plate 9 of the fish-belly corrugated steel web beam 2 along the length direction, and epoxy mortar is applied inside the rubber strip 8 of the top plate 9, and the fish-belly corrugated steel web beam 2 is installed. The fish-belly corrugated steel web beam 2 is fixed by the anchor bolts 6 on both sides of the side plate of the hollow slab beam 1, and the fish-belly corrugated steel web beam 2 is tightened upward after being installed in place;

[0032] S04. After the fish-belly corrugated steel web beam 2 is installed, the prestressed carbon plate 3 is tensioned on the bottom plate 10 of the fish-belly corrugated steel web to the set load, and the flat shape of the prestressed carbon plate 3 is utilized to make the prestressed carbon plate 3 completely fit with the bottom plate 10 of the fish-belly corrugated steel web beam 2, and the tensioned prestressed carbon plate 3 is fixed. The prestressed carbon plate 3 is anchored on the prestressed anchoring device 4 in the anchoring area at both ends of the fish-belly corrugated steel web beam 2, and the hollow slab beam 1 with damaged hinge joints is reset by the upward radial force generated by the prestressed carbon plate 3 on the bottom plate 10 of the fish-belly corrugated steel web beam 2. Similarly, the upward radial force generated by the active tensioning of the prestressed carbon plate 3 can also ensure that there will be no problem of single hollow slab stress when vehicles are driving on the bridge deck.

[0033] As a preferred embodiment of the present invention, an anchoring steel plate 7 is provided at the beam end of the fish-bellied corrugated steel web beam 2, and the anchoring steel plate 7 is connected to the outer web of the side plate of the hollow slab beam 1 by an embedded anchor bolt 6.

[0034] As a preferred embodiment of the present invention, it further comprises a stiffening plate 5 , which is welded to the outside of the anchoring steel plate 7 to prevent out-of-plane deformation of the anchoring steel plate 7 .

[0035] As a preferred embodiment of the present invention, the prestressed anchoring device 4 is welded on the stiffening plate 5 .

[0036] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An active reinforcement method for solving the stress of a hollow slab, characterized in that: The construction steps include: S01. Determine the installation position of the fish-belly corrugated steel web beam, and grind the bottom surface of the hollow slab beam and the side surface of the side plate at the installation position; S02. Drill holes on the side of the hollow slab beam and install the screws of the anchor bolts; S03. Apply epoxy mortar on the top plate of the fish-belly corrugated steel web beam, install the fish-belly corrugated steel web beam, and fix the fish-belly corrugated steel web beam through anchor bolts on both sides of the hollow slab beam side plate; S04. Tension the prestressed carbon plate on the bottom plate of the fish-belly corrugated steel web to a set load, so that the prestressed carbon plate is completely fitted with the bottom plate of the corrugated steel web beam, and the tensioned prestressed carbon plate is fixed.

2. The active reinforcement method for solving the stress of a hollow slab according to claim 1 is characterized in that: The fish-bellied corrugated steel web beam described in step S01 is transversely installed at the bottom of the 1 / 2 length section beam and the bottom of the 1 / 4 length section beam in the middle of the span of the hollow slab bridge.

3. The active reinforcement method for solving the stress of a hollow slab according to claim 1 is characterized in that: The top plate of the fish-bellied corrugated steel web beam in step S01 is a rectangular surface, and the cross-section of the fish-bellied corrugated steel web beam is an arc shape, with the highest beam height at the bridge axis and the lowest beam height near the two sides.

4. The active reinforcement method for solving the stress of a hollow slab according to claim 1 is characterized in that: In step S01, anchoring steel plates are arranged at both side beam ends of the fish-belly corrugated steel web beam, and the anchoring steel plates are connected to the outer web of the side plates of the hollow slab beam by embedded anchor bolts.

5. The active reinforcement method for solving the stress of a hollow slab according to claim 4 is characterized in that: It also includes a stiffening plate, which is welded to the outside of the anchoring steel plate to prevent out-of-plane deformation of the anchoring steel plate.

6. The active reinforcement method for solving the stress of a hollow slab according to claim 5 is characterized in that: It also includes a prestressed anchor device, which is welded to the stiffening plate.

7. The active reinforcement method for solving the stress of a hollow slab according to claim 1 is characterized in that: Before installing the fish-belly corrugated steel web beam in step S03, 5 mm thick high-durability rubber strips are pasted on both sides above the top plate of the fish-belly corrugated steel web beam along the length direction, and the epoxy mortar is applied to the inside of the rubber strips of the top plate. After the fish-belly corrugated steel web beam is installed in place, it is tightened upward.

8. The active reinforcement method for solving the stress of a hollow slab according to claim 6 is characterized in that: The prestressed carbon plate described in step S04 is anchored on the prestressed anchoring devices at the anchoring areas at both ends of the fish-belly corrugated steel web beam.

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