CN-117966629-B - Anti-overturning reinforcing construction method for bridge bent cap

CN117966629BCN 117966629 BCN117966629 BCN 117966629BCN-117966629-B

Abstract

The invention discloses an anti-overturning reinforcement construction method for a bridge bent cap, belongs to the technical field of building reinforcement, and aims to solve the problem that the performance of a steel plate of a bonded steel reinforced repair bent cap cannot be fully exerted. According to the invention, a plurality of chemical anchors are arranged on two side surfaces and two end surfaces of the bent cap, stiffening rib plates are arranged at two ends of the bent cap, second steel plates are arranged at the outer sides of the two stiffening rib plates, first steel plates are arranged at the front side and the rear side of the bent cap, the two second steel plates and the two first steel plates are sequentially connected end to form a containment plate frame, each chemical anchor on the two end surfaces of the bent cap is in threaded connection with one tensioning nut, and a plurality of tensioning nuts are reversely screwed, so that the tensioning nuts exert pressure on the second steel plates at the same side, and further the second steel plates exert tensioning force on the first steel plates, and finally epoxy resin glue is injected between the first steel plates and the bent cap to form the stress of the integral structure. The first steel plate stressed on the front side and the rear side of the bent cap can greatly improve the service efficiency of the first steel plate and save the material consumption due to the prestress.

Inventors

CHEN LIJIAN
ZHANG JIAN
HU LILIN
LI ZUCHENG
LI DAQIANG
LI JI
LU YONG
WU PENGFEI
DING JIA
Mao Jiyi
ZHANG XIN
WEN YANFENG
WANG SHUANGQI

Assignees

成都市市政开发总公司

Dates

Publication Date: 20260505
Application Date: 20240315

Claims (6)

1. An anti-overturning reinforcement construction method for a bridge bent cap, which is characterized by setting the bent cap (1) left and right and comprising the following steps: repairing the existing cracks of the bent cap (1); step two, roughening the to-be-bonded areas of the front side surface, the rear side surface, the left end surface and the right end surface of the capping beam (1) to expose bone materials of the capping beam (1), and cleaning floating dust on the surface of the capping beam (1) by using an iron brush or compressed air; Detecting main ribs of the capping beam (1), respectively avoiding the main ribs on to-be-bonded areas of the front side surface, the rear side surface, the left end surface and the right end surface of the capping beam (1), drilling a plurality of rib holes, firstly injecting a rib-planting adhesive into each rib hole, then inserting a plurality of chemical anchor bolts (7) into the plurality of rib holes in a one-to-one correspondence manner, waiting for the solidification of the rib-planting adhesive, and bonding the chemical anchor bolts (7) and the capping beam (1) into a whole; Step four, first steel sheet (2), second steel sheet (3), stiffening rib plate (4), tensioning nut (5) and consolidate half surrounding frame (8) to carry out surface rust cleaning, decontaminate and handle, first steel sheet (2), second steel sheet (3) and stiffening rib plate (4) are rectangular steel sheet, the length of stiffening rib plate (4) sets up according to the width of bent cap (1), the length of first steel sheet (2) equals the sum of the length of bent cap (1) and the width of two stiffening rib plates (4), the length of second steel sheet (3) equals the sum of the width of bent cap (1) and the thickness of two first steel sheets (2), set for the sectional area of first steel sheet (2) and be S, unit is m 2 , S is confirmed through following formula: S= ; wherein: F is the pressure required to be applied to the end face of the bent cap (1), and the unit is N; l is the length of the first steel plate (2) and the unit is m; Δl is the elongation elastic deformation quantity of the first steel plates (2) with the unit of m when the tensile stress received by both ends is F after the superposition and combination of the two first steel plates (2); Δl is determined by: ΔL = (σ/E)× L=[(F/S)/E]×L; wherein: Sigma is Xu Yongla stress of the first steel plate (2), and the unit is MPa; E is the elastic modulus of the first steel plate (2) with the unit of MPa; Step five, two stiffening rib plates (4) are respectively and horizontally arranged at the left end and the right end of the bent cap (1), a plurality of leakage openings (41) are arranged on the stiffening rib plates (4), the front end and the rear end of the stiffening rib plates (4) are respectively and correspondingly aligned with the front side and the rear side of the bent cap (1), the inner side edges of the stiffening rib plates (4) are respectively abutted against the to-be-bonded areas of the corresponding end surfaces of the bent cap (1), the stiffening rib plates (4) are positioned at the vertical middle parts of the to-be-bonded areas, two first steel plates (2) are respectively and parallelly arranged at the front side and the rear side of the bent cap (1), the inner end surfaces of the first steel plates (2) are abutted against the to-be-bonded areas of the corresponding side surfaces of the bent cap (1), a plurality of oblong holes (21) which a plurality of chemical anchor bolts (7) penetrate through are arranged on the corresponding side surfaces of the bent cap (1) are arranged on the first steel plates (2), the left side and the right side of the oblong holes (21) are respectively aligned with the outer side edges of the two stiffening rib plates (4), two second steel plates (3) are arranged in parallel to each other at the two sides of the corresponding to the outer sides of the two stiffening rib plates (4), the two second steel plates (3) are respectively aligned with the two corresponding inner side edges of the two stiffening rib plates (3) respectively, the tensioning nuts (5) comprise inner screw thread sections (51), one end of each inner screw thread section (51) is provided with a base plate (52), each chemical anchor bolt (7) on the left end face and the right end face of the bent cap (1) is in threaded fit with one tensioning nut (5) and one locking nut (6), the tensioning nuts (5) are respectively abutted against the inner end faces of the second steel plates (3) on the same side through the base plates (52), the two first steel plates (2) and the two second steel plates (3) are sequentially connected end to form a containment sheet frame, the reinforcing semi-surrounding frame (8) is in a shape of 匚, the two reinforcing semi-surrounding frames (8) are respectively wrapped on the outer sides of the two second steel plates (3), and two ends of the reinforcing semi-surrounding frame (8) are respectively connected with the two first steel plates (2); Step six, selecting the jack (9) according to the compressive stress F applied to the end face of the capping beam (1), so that F=f×n, wherein F is the working force output by the jack (9), and n is the number of the jacks; Setting n jacks (9) between the end face of the capping beam (1) and the second steel plate (3) on the same side, when the jacks (9) are propped between the inner side end face of the corresponding second steel plate (3) and the capping beam (1), respectively applying tensile force to the left side and the right side of the two first steel plates (2) by the two second steel plates (3), respectively horizontally pasting a plurality of strain gauges (22) on the outer end faces of the two first steel plates (2) at intervals, sequentially extruding piston rods of each n jacks (9) according to the sequence of the first middle side and the second side, outputting data according to the plurality of strain gauges (22), enabling each jack to provide tensile force of 40%f for the first steel plates (2), sequentially extruding piston rods of each n jacks (9) according to the sequence of the first middle side and the second side, outputting data according to the plurality of strain gauges (22), enabling the tensile force provided by each jack to the first steel plate (2) to be f, reversely screwing a plurality of tensioning nuts (5), and enabling the tensioning nuts (5) to be propped against the second steel plates (3) on the same side according to the output data of the first steel plates (52); step eight, after tensioning the two first steel plates (2), respectively smearing epoxy resin glue with the thickness of more than or equal to 2mm on the areas to be bonded corresponding to the side surfaces of the first steel plates (2) and the bent cap (1), and bonding the first steel plates (2) and the bent cap (1) by adopting pressure glue injection; Step nine, before the epoxy resin glue is solidified, fastening nuts (71) are respectively arranged on a plurality of chemical anchor bolts (7) on the front side and the rear side of the bent cap (1), the fastening nuts (71) are screwed down, two first steel plates (2) are fixed on the chemical anchor bolts (7) on the front side and the rear side of the bent cap (1), and a plurality of locking nut (6) are reversely screwed down, so that locking nut (6) is abutted against the corresponding tensioning nuts (5); step ten, timely scraping off excessive epoxy resin glue extruded from the edge of the first steel plate (2); Step eleven, after the epoxy resin glue solution is solidified, installing a bottom die between the lower edge of the second steel plate (3) and the bent cap (1), filling slurry into a cavity between the second steel plate (3) and the bent cap (1) to be filled, so that the slurry wraps the stiffening rib plates (4); and step twelve, after the poured slurry is solidified, removing the bottom die, and carrying out anti-corrosion coating on the exposed surfaces of the first steel plate (2), the second steel plate (3) and the reinforced semi-surrounding frame (8).
2. The method for anti-overturning reinforcing a bridge bent cap according to claim 1, wherein the first steel plate (2) is a Q355 steel plate.
3. The method for anti-overturning reinforcing of bridge bent cap according to claim 2, wherein the height of the first steel plate (2) is 400mm.
4. The method for anti-overturning reinforcing a bridge bent cap according to claim 1, wherein the second steel plate (3) is a Q355 steel plate.
5. The method for anti-overturning reinforcing a bridge bent cap according to claim 1, wherein the stiffening rib plate (4) is a Q355 steel plate.
6. The method for anti-overturning reinforcing of bridge bent cap according to any one of claims 1-5, wherein the two first steel plates (2) and the two second steel plates (3) are connected in sequence by end-to-end penetration welding.

Description

Anti-overturning reinforcing construction method for bridge bent cap Technical Field The invention belongs to the technical field of building reinforcement, and particularly relates to an anti-overturning reinforcement method for a bridge bent cap. Background The bent cap refers to a reinforced concrete beam arranged at the top of the bent pile pier for supporting, distributing and transmitting the load of the upper structure. The main function is to support the bridge superstructure and to transfer the full load to the substructure. The bonding steel reinforcement is a construction method for bonding a steel plate to the surface of a concrete structure by adopting a high-performance epoxy adhesive, so that the steel plate and the concrete form a unified whole, and the bearing capacity and the rigidity of the concrete structure are enhanced by utilizing the good tensile strength of the steel plate. The construction method is used for anti-overturning reinforcement of the existing bridge bent cap, is an effective reinforcement method of the current mainstream, has the advantages of being simple and rapid to operate, does not increase the dead weight of the bent cap structure, has the defects that the reinforcement of the bent cap belongs to passive reinforcement, the performance of bonded steel plates cannot be fully exerted, the effective bearing capacity of the steel plates can only be exerted within 20% of the design bearing capacity under the general condition, and is not suitable for the bent cap structure with larger bearing capacity lifting requirement after reinforcement. Disclosure of Invention The invention aims to provide an anti-overturning reinforcing method for a bridge bent cap, which aims to solve the problem that the performance of a steel plate of a bonded steel reinforced repair bent cap cannot be fully exerted. The technical scheme adopted by the invention is as follows: an anti-overturning reinforcement construction method for a bridge bent cap, which sets the left and right arrangement of the bent cap, comprises the following steps: Step one, repairing the existing cracks of the bent cap; step two, roughening the to-be-bonded areas of the front side surface, the rear side surface, the left end surface and the right end surface of the capping beam to expose bone materials of the capping beam, and cleaning floating dust on the surface of the capping beam by using an iron brush or compressed air; Detecting main reinforcements of the capping beam, drilling a plurality of reinforcement holes on to-be-bonded areas of the front side surface, the rear side surface, the left end surface and the right end surface of the capping beam respectively avoiding the main reinforcements, firstly injecting reinforcement glue into each reinforcement hole, then inserting a plurality of chemical anchor bolts into the plurality of reinforcement holes in a one-to-one correspondence manner, waiting for solidification of the reinforcement glue, and bonding the chemical anchor bolts and the capping beam into a whole; step four, manufacturing a first steel plate, a second steel plate, stiffening rib plates, tensioning nuts and reinforcing semi-surrounding frames, performing surface rust removal and decontamination treatment, wherein the first steel plate, the second steel plate and the stiffening rib plates are rectangular steel plates, the length of each stiffening rib plate is set according to the width of a bent cap, the length of the first steel plate is equal to the sum of the length of the bent cap and the width of two stiffening rib plates, the length of the second steel plate is equal to the sum of the width of the bent cap and the thickness of two first steel plates, the sectional area of the first steel plate is set to be S, the unit is m 2, and S is determined by the following formula: wherein: F is the compressive stress to be applied to the end face of the bent cap, and the unit is N; L is the length of the first steel plate, and the unit is m; Delta L is the elongation elastic deformation quantity of the first steel plates with the unit of m when the tensile stress received by both ends is F after the superposition and combination of the two first steel plates; Δl is determined by: ΔL=(σ/E)×L=[(F/S)/E]×L wherein: sigma is Xu Yongla stress of the first steel plate, and the unit is MPa; E is the elastic modulus of the first steel plate, and the unit is MPa; The fifth step, two stiffening rib plates are respectively and horizontally arranged at the left and right ends of the capping beam, a plurality of leakage openings are arranged on the stiffening rib plates, the front and rear ends of the stiffening rib plates are respectively and correspondingly aligned with the front and rear sides of the capping beam, the inner side edges of the stiffening rib plates are propped against the to-be-bonded areas of the corresponding end faces of the capping beam, the stiffening rib plates are positioned at the vertic