Replacement method for double-side balanced counter-pulling support of single-column pier continuous box girder bridge

Abstract

The application discloses a kind of single-column pier continuous box girder bridge double-side balanced tension type support replacement method, comprising the following steps: step S1, pier steel hoop is installed at the top of pier column, and jack is arranged at the both sides of support cushion stone to lift box girder beam body;Step S21, at a certain distance from the both sides of support, anchor bolt is injected at beam bottom, and anchor ring is welded to form tensioning lifting point;Step S22, two sides lifting point each arrangement hand-operated hoist, support steel hoop is installed on support, and it is connected by the pull ring connection of hand-operated hoist and support steel hoop;Step S23, side is used hand-operated hoist to pull support, and balanced force is formed to make support suspended from single-column pier top;Step S24, two hand-operated hoists are pulled in and out, and old support is gradually taken out and lowered;Step S25, reverse operation, new support is lifted and installed on single-column pier top support cushion stone.The application has the advantages of high, large quality single-column pier old support replacement speed, high safety factor and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bridge construction, and more particularly to a method for replacing double-side balanced counter-pull type bearings of single-column pier continuous box girder bridges. BACKGROUND

[0002] With the continuous advancement of urbanization, the traffic flow presents an explosive growth, which also brings serious traffic congestion problems. In order to alleviate the increasingly severe traffic pressure, the state has begun to construct a large number of hub interchanges in cities and high-grade highways. As a common type of bridge form of overpass and ramp bridge engineering, the single-column pier continuous box girder bridge has the advantages of beautiful appearance and small space requirement, and the lateral overturning problem of the single-column pier continuous box girder bridge with single bearing is very prominent. With the aging of the single-column pier bridge and the increasing busy transportation, how to safely, quickly and efficiently reinforce and reconstruct the bridge to prevent the occurrence of overturning accidents of the bridge is the work that must be continuously researched and carried out by highway bridge managers and engineers.

[0003] Investigation and analysis shows that the common points of the single-column pier bridge overturning events are: ① the upper structure is basically integrally cast box girder, and the support form is mostly single bearing; ② the bridge is in good actual use condition before the accident, and the bridge structure system does not have major diseases and damages, the accident occurs suddenly, and the upper structure and the lower structure of the bridge basically remain good after the accident; ③ no obvious damage occurs except the bearing, the accident is mostly caused by special or overweight vehicles, and these vehicles drive on one side of the bridge, and the structure support system fails under the eccentric action of the vehicle load. Therefore, the aged and deformed bearing is one of the main causes of the overturning of the single-column pier single bearing bridge.

[0004] In the process of anti-overturning reinforcement of the single-column pier bridge, synchronous replacement of the aged bearing faces two difficult problems:

[0005] ① The single-column pier top section is mostly occupied by bearing cushion stones, and the space for placing the jack is limited;

[0006] ② The net height of the single-column pier is high, the weight of the bearing is large, the bearing is manually moved by relying on the support, there is a great safety hazard, and it is difficult for manpower to directly move the bearing with a weight of 300-800 kg. SUMMARY

[0007] The purpose of the present application is to provide a method for replacing double-side balanced counter-pull type bearings of single-column pier continuous box girder bridges, which has the advantages of fast speed, high safety factor and the like in replacing the old bearing of the single-column pier with high net height and large mass.

[0008] The technical solution adopted by the present application to solve the technical problem is: a method for replacing double-side balanced counter-pull type bearings of single-column pier continuous box girder bridges, comprising the following steps:

[0009] Step S1, install the pier steel hoop on the top of the pier column, and arrange the jack on both sides of the support cushion stone, and load and synchronously lift the box girder according to the preset loading speed;

[0010] Step S21, inject the anchor bolt at the bottom of the beam at a certain distance from both sides of the support, and weld the anchor ring to form the pulling hanging point;

[0011] Step S22, arrange the chain hand-operated hoist on both sides of the hanging point, install the support steel hoop on the support, and connect the chain hand-operated hoist with the pull ring of the support steel hoop;

[0012] Step S23, use the chain hand-operated hoist to pull the support steel hoop on both sides to form a balanced force to make the support suspended and separated from the top of the single-column pier;

[0013] Step S24, pull in and pull out the two chain hand-operated hoists to gradually take out and lower the old support;

[0014] Step S25, reverse the operation to lift and install the new support on the support cushion stone on the top of the single-column pier.

[0015] Preferably, the step S1 specifically comprises:

[0016] Step S11, install the processed pier steel hoop on the top of the pier column, and tighten it with high-strength bolts to make the cover plate close to the support cushion stone and the ring-shaped steel plate of the pier steel hoop close to the pier column;

[0017] Step S12, arrange the jack on the cover plate of the pier steel hoop, and arrange the jacks on both sides of the support cushion stone, and the number of jacks is determined by model calculation of support reaction force and corresponding lifting tonnage;

[0018] Step S13, install the hydraulic synchronous lifting control system and the hydraulic locking device;

[0019] Step S14, load and synchronously lift according to the preset loading speed, control the lifting speed to be less than or equal to 1mm / min, and after the lifting reaches the designed height, set a stable temporary support cushion (steel wedge) parallel to the jack, and then replace the support.

[0020] Preferably, the connection mode of the two groups of chain hand-operated hoists in the step S22 is:

[0021] One chain hand-operated hoist is connected with the anchor ring and connected with the fixed pulley of the beam bottom hanging point and the pull ring of the support steel hoop through the steel wire rope; the other chain hand-operated hoist is connected with the anchor ring of the beam bottom and the pull ring of the support steel hoop; or,

[0022] Both chain hand-operated hoists are connected with the anchor ring at one end and connected with the fixed pulley of the beam bottom hanging point and the pull ring of the support steel hoop through the steel wire rope; or,

[0023] Two chain hoists are connected with the anchor ring of the beam bottom and the pull ring of the support steel hoop.

[0024] No matter which connection form is used, the two chain hoists form a balanced pair of pullers, so that the old / new support is suspended, facilitating the replacement of the support.

[0025] Preferably, the pier steel hoop is composed of a structural cover plate, a rib plate, a spliced pier steel hoop annular steel plate and pier steel hoop high-strength bolts; the spliced pier steel hoop annular steel plate is tightly attached to the pier by the pier steel hoop high-strength bolts; the pier steel hoop annular steel plate is connected with the structural cover plate and the rib plate by welding; the structural cover plate is tightly attached to the support cushion stone, serving as the base platform and the lower cushion plate of the hydraulic jack; the rib plate connects the structural cover plate and the pier steel hoop annular steel plate by welding, serving as a support for the cover plate and a pressure conductor.

[0026] Preferably, the support steel hoop is composed of a spliced support steel hoop annular steel plate, support steel hoop high-strength bolts and a pull ring; the spliced support steel hoop annular steel plate is tightly attached to the support by the support steel hoop high-strength bolts; the pull ring is connected with the support steel hoop annular steel plate by welding, serving as the pulling force point of the chain hoist.

[0027] The present application at least has the following advantages:

[0028] 1. The pier steel hoop used in the method for replacing the double-side balanced pair of pullers of the support of the single-column pier continuous box girder bridge does not need to be implanted with anchor bolts, has zero damage to the original pier and can be reused.

[0029] 2. The chain hoist used in the method for replacing the double-side balanced pair of pullers of the support of the single-column pier continuous box girder bridge balances the pair of pullers, and through reasonable design of the lifting point position, the chain hoist can realize the taking out and lowering of the old support and the lifting and installation of the new support in the narrow space, can greatly reduce the height of the jacking, is simple and easy to operate and has high safety.

[0030] 3. The method for replacing the double-side balanced pair of pullers of the support of the single-column pier continuous box girder bridge can be combined with the construction of the lifting frame, so that the construction of the scaffold in the super-high clearance can be avoided and the construction difficulty of the replacement of the support in the high clearance can be greatly reduced.

[0031] 4. The method for replacing the double-side balanced pair of pullers of the support of the single-column pier continuous box girder bridge can be combined with the hydraulic synchronous jacking control system, so that the synchronous jacking of the replacement of the support of the multi-span continuous girder bridge can be realized.

[0032] Other advantages, objects and features of the present application will be partly embodied by the following description and partly understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A longitudinal bridge section view of an embodiment of the present application;

[0034] Figure 2 A transverse bridge section view of an embodiment of the present application;

[0035] Figure 3 A plan view of a pier steel hoop of an embodiment of the present application;

[0036] Figure 4 A model perspective view of a pier steel hoop of an embodiment of the present application;

[0037] Figure 5 A plan view of a support steel hoop of an embodiment of the present application

[0038] Figure 6 A front view of a support steel hoop of an embodiment of the present application;

[0039] Figure 7 A force analysis diagram of a support steel hoop of the present application.

[0040] The figure marks: 1-1# chain type hand-operated hoist; 2-1# chain type hand-operated hoist hand-pulled chain; 3-ground anchor ring; 4-fixed pulley; 5-2# chain type hand-operated hoist; 6-2# chain type hand-operated hoist hand-pulled chain; 7-beam bottom anchor ring; 8-support steel hoop; 9-structure cover plate; 10-rib plate; 11-pier steel hoop annular steel plate; 12-hydraulic jack upper pad plate; 13-hydraulic jack; 14-pier steel hoop high-strength bolt; 81-support steel hoop high-strength bolt; 82-support steel hoop annular steel plate; 83-pull ring. DETAILED DESCRIPTION

[0041] The present application will be described in detail below with reference to the drawings. Those skilled in the art will be able to implement the present application based on these descriptions. Before the present application is described in detail with reference to the drawings, it is particularly pointed out that the technical solutions and technical features provided in each part of the present application, including the following description, can be combined with each other without conflict.

[0042] In addition, the embodiments of the present application involved in the following description are generally only a part of the embodiments of the present application, not all the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor should belong to the scope of protection of the present application.

[0043] The present application will be described in detail below with reference to the drawings. Those skilled in the art will be able to implement the present application based on these descriptions. Before the present application is described in detail with reference to the drawings, it is particularly pointed out that the technical solutions and technical features provided in each part of the present application, including the following description, can be combined with each other without conflict.

[0044] A method for replacing the double-sided balanced tie-type bearings of a single-column pier continuous box girder bridge includes two steps: lifting the pier column steel clamp with a jacking platform and replacing the bearings using a chain-type hand-operated hoist for balanced tie-type operation. The specific construction method is as follows:

[0045] (1) Use steel clamps for piers and a jacking platform to lift.

[0046] ①For example Figures 3-4 As shown, the pier steel clamp consists of a structural cover plate 9, a rib plate 10, a spliced ​​pier steel clamp ring steel plate 11, and pier steel clamp high-strength bolts; the processed pier steel clamp is spliced ​​and installed on the top of the pier, and fastened with pier steel clamp high-strength bolts 14, so that the structural cover plate 9 is in close contact with the bearing pad stone, and the pier steel clamp ring steel plate 11 is in close contact with the pier;

[0047] ② Hydraulic jacks 13 and hydraulic jack pads 12 are arranged on the structural cover plate 9. The hydraulic jacks 13 are arranged on both sides of the support pad stone. The number of jacks is determined by calculating the support reaction force and the corresponding lifting tonnage through model calculation.

[0048] ③ Install a hydraulic synchronous jacking control system and a hydraulic locking device;

[0049] ④ Load and lift synchronously according to the preset loading speed, control the lifting speed to ≤1mm / min. After the lifting reaches the design height, set a stable temporary support (steel wedge) parallel to the jack, and then replace the support.

[0050] (2) Use a chain-type hand chain hoist to balance and replace the support.

[0051] ① At a certain distance from both sides of the support, inject anchor bolts into the bottom of the beam and weld anchor rings to form tie-down points;

[0052] ②A chain-type hand chain hoist is arranged at each of the two lifting points. A support steel clamp 8 is installed on the support. One side of the support steel clamp 8 is directly connected to the chain-type hand chain hoist, and the other side is connected to the chain-type hand chain hoist by passing a steel wire rope through the fixed pulley 4.

[0053] ③ The side is pulled by a chain-type hand-operated hoist to pull the steel clamp of the support 8, forming a balanced force so that the support is suspended and detached from the top of the single column pier.

[0054] like Figure 7 As shown, the supports are lifted from both sides, causing them to detach from the pier. According to the force balance relationship, we can obtain:

[0055]

[0056] In the formula: θ1, θ2—the vertical angles between the two traction chains and the bottom of the beam;

[0057] N p1 Np2 —The traction force of the chains on both sides;

[0058] F—The weight of the support and the support clamp;

[0059] If the lifting is symmetrical and synchronous on both sides, then θ = θ1 = θ2, and the traction force on both sides is:

[0060]

[0061] When the angle is small, the traction force can be simplified to:

[0062]

[0063] Theoretically, when the weight F of the support to be lifted is constant, and without considering factors such as limited actual operating space, the closer the anchor point at the bottom of the beam is to the support, the smaller the required traction force. After the support is lifted and detached, the vertical distance between the support clamp lifting point and the anchor point at the bottom of the beam is Δh. If the design bearing capacity of the anchor point at the bottom of the beam is known as N, then the distance between the optimal anchoring position at the bottom of the beam and the support can be calculated using equation (1.2).

[0064] ④ Use two chain-type hand-operated hoists to pull forward and backward in opposite directions, gradually removing and lowering the old support;

[0065] ⑤ Reverse the operation, lift the new support and install it on the support pad stone at the top of the single column pier.

[0066] Example 1

[0067] like Figures 1-2 As shown, the No. 1 single-column pier of the continuous box girder viaduct needs to be jacked up and the bearing replaced. Its basic information is as follows: the diameter of the single-column pier is 1.3m, the clearance height is 18m, and the bearing reaction force at the top of the pier is 420t; the old bearing model is GYZφ800*140mm circular plate rubber bearing, and the weight reaches 480kg; the designed jacking height is 10mm.

[0068] Step 1: Process the spliced ​​annular steel clamps (1.5mm thick, 400mm high). The diameter of the spliced ​​pier steel clamps is 1.32m, and the outer diameter of the cover plate is 1.47m. Install the spliced ​​pier steel clamps on the top of the pier and tighten them with high-strength bolts 14, so that the cover plate is tightly attached to the bearing pad stone and the annular steel plate 11 of the pier steel clamp is tightly attached to the pier.

[0069] Step 2: At a distance of 1.5m from both sides of the pier, inject anchor bolts into the bottom of the beam and weld anchor rings to form tie-down points;

[0070] Step 3: Arrange a #1 chain-type hand chain hoist 1 (with a #1 chain-type hand chain hoist 1 hand chain 2) and a #2 chain-type hand chain hoist 5 (with a #2 chain-type hand chain hoist 5 hand chain 6) at each of the two lifting points, as follows: Figures 5-6As shown, the support steel hoop 8 is installed on the support, which is composed of a split support steel hoop ring steel plate 82, a support steel hoop high-strength bolt 81 and a pull ring 83; the 2# chain hand-operated hoist 5 connects the beam bottom anchor ring 7 and the pull ring 83, and the 1# chain hand-operated hoist 1 connects the ground anchor ring 2 and pulls the beam bottom fixed pulley 4 and the pull ring of the support steel hoop 8 through the steel wire rope. As shown, Figure 1 As shown,

[0071] Step 4: Four jacks (each jack has a lifting force of 200t, and the counterforce provided at one time is 800t) are arranged on the pier steel hoop cover plate, and the jacks are arranged on both sides of the support cushion stone, perpendicular to the pull ring direction of the support steel hoop 8;

[0072] Step 5: Install the hydraulic synchronous lifting control system and install the hydraulic locking device;

[0073] Step 6: Load synchronously according to the preset loading speed, control the beam speed ≤1mm / min, and when the lifting height reaches 10mm, a stable temporary support pad (steel wedge) is arranged parallel to the jacks, and then the support is replaced.

[0074] Step 7: The 5T chain hand-operated hoist is used to pull the support steel hoop 8 (thickness 1mm, height 100mm) on the side, to form a balanced force to make the support suspended and separated from the pier top of the single column pier;

[0075] Step 8: Two chain hand-operated hoists are used to pull in and pull out, gradually taking out and lowering the old support;

[0076] Step 9: Reverse operation, lift and install the new support on the support cushion stone of the single column pier pier top;

[0077] Step 10: After the replacement of the support is completed, the beam is reset.

[0078] Example 2

[0079] The 2# single column pier of the continuous box girder viaduct needs to be lifted to replace the support, and the related basic information is as follows: the diameter of the single column pier is 1.4m, the net height is 21m, and the support counterforce on the pier top is 600t; the old support type is GYZφ900*140mm circular plate type rubber support, and the weight reaches 620kg; the design lifting height is 15mm.

[0080] Step 1: Process the split ring steel hoop (thickness 1.5mm, height 400mm), and the diameter of the split pier steel hoop is 1.42m, and the outer diameter of the cover plate is 1.57m; the split pier steel hoop is installed on the top of the pier, and the pier steel hoop high-strength bolt 14 is used to tighten the cover plate to tightly adhere to the support cushion stone, and the pier steel hoop ring steel plate 11 tightly adheres to the pier;

[0081] Step 2: Inject anchor bolt at the beam bottom at a distance of 1.5m from both sides of the pier column, and weld anchor ring to form a pulling hoisting point;

[0082] Step 3: Arrange chain hand-operated hoist at both sides of the hoisting point, one side is directly connected with the chain hand-operated hoist, and the other side is connected with the chain hand-operated hoist through a fixed pulley 4 by a steel wire rope;

[0083] Step 4: Arrange 6 jacks (the jacking force of each jack is 200t, and the counterforce provided at one time is 1200t) on the pier steel hoop cover plate, and the jacks are arranged at both sides of the support cushion stone and perpendicular to the pulling ring direction of the support steel hoop 8;

[0084] Step 5: Install hydraulic synchronous jacking control system and hydraulic locking device;

[0085] Step 6: Load and synchronously jack up according to the preset loading speed, control the beam lifting speed to be less than or equal to 1mm / min, and after the jacking height reaches the design height, a stable temporary support pad (steel wedge) is arranged in parallel with the jacks, and then the support is replaced.

[0086] Step 7: The support steel hoop 8 (thickness 1mm, height 100mm) is pulled by 5T chain hand-operated hoist on the side, to form a balanced force to make the support suspended and separated from the top of the single column pier;

[0087] Step 8: The two chain hand-operated hoists pull in and pull out, and gradually take out and lower the old support;

[0088] Step 9: Reverse operation, lift and install the new support on the support cushion stone of the single column pier;

[0089] Step 10: After the support replacement is completed, the beam is reset.

[0090] Although the embodiments of the present application have been disclosed as above, they are not limited to the application listed in the specification and the embodiments, and can be fully applied to various fields suitable for the present application, and other modifications can be easily realized by those skilled in the art, and therefore the present application is not limited to specific details and the embodiments shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A method for replacing a double-sided balanced pull-type support of a single-column pier continuous box girder bridge, characterized in that, The method comprises the following steps: Step S1, installing a pier steel hoop on the top of the pier column, the pier steel hoop being composed of a structural cover plate, a rib plate, a spliced pier steel hoop annular steel plate, and pier steel hoop high-strength bolts; the spliced pier steel hoop annular steel plate is tightly attached to the pier column through the pier steel hoop high-strength bolts and does not need to be implanted and anchored, and can be reused; a jack is arranged on both sides of the support cushion stone on the pier steel hoop cover plate, a hydraulic synchronous jacking control system is installed, the box girder is loaded and synchronously jacked at a preset loading speed, the jacking speed is controlled to be less than or equal to 1 mm / min, and after the jacking reaches the design height, a temporary support cushion is arranged in parallel with the jack; Step S21, injecting an anchor bolt at a certain distance from both sides of the support and welding an anchor ring to form a pulling hoisting point at the bottom of the beam; Step S22, arranging a hand-operated hoist on both sides of the hoisting point, installing a support steel hoop on the support, the support steel hoop being composed of a spliced support steel hoop annular steel plate, support steel hoop high-strength bolts, and a pull ring; the spliced support steel hoop annular steel plate is tightly attached to the support through the support steel hoop high-strength bolts, and the pull ring is welded to the support steel hoop annular steel plate and connected to the pull ring through the hand-operated hoist; Step S23, using the hand-operated hoist to pull the support steel hoop on the side, based on the force balance relationship: （1.1） a balanced force is formed to make the support suspended and separated from the top of the single-column pier, and a small pulling force is used to overcome the self-weight and adhesion of the support; Step S24, pulling and pulling out the old support by two hand-operated hoists; Step S25, reversely operating to lift and install the new support on the support cushion stone on the top of the single-column pier.

2. The method of claim 1, wherein the method is characterized by: The connection mode of the two groups of hand-operated hoists in step S22 is: one hand-operated hoist is connected to the anchor ring and connected to the pull ring of the support steel hoop through a steel wire rope and a fixed pulley connected to the hoisting point at the bottom of the beam; the other hand-operated hoist is connected to the anchor ring at the bottom of the beam and the pull ring of the support steel hoop; or, both hand-operated hoists are connected to the anchor ring at one end and connected to the pull ring of the support steel hoop through a steel wire rope and a fixed pulley connected to the hoisting point at the bottom of the beam; or, both hand-operated hoists are connected to the anchor ring at the bottom of the beam and the pull ring of the support steel hoop.

3. The method of claim 1, wherein the method is characterized by: The pier steel hoop annular steel plate is connected to the structural cover plate and the rib plate through welding; the structural cover plate is tightly attached to the support cushion stone; and the rib plate is connected to the structural cover plate and the pier steel hoop annular steel plate through welding.

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