Pre-pressing device for counter-force beam of suspended pouring box beam

Abstract

The utility model discloses a suspension casting box girder counter-force beam prepressing device which comprises a No.0 block, a triple-spliced counter-force beam anchored on a bottom plate of the No.0 block, finish rolling deformed steel bars anchored on the triple-spliced counter-force beam and bolts, carrying pole beams are arranged at the rear ends of the two sides of the triple-spliced counter-force beam, jacks are arranged on the lower sides of the triple-spliced counter-force beam on the two sides of the top, and the top of the top of the triple-spliced counter-force beam is connected with the top of the top of the triple-spliced counter-force beam. A double-splicing tool 32b transverse distribution beam and a double-splicing tool 32b longitudinal distribution beam are arranged on the lower side of the jack, two three-splicing H488 counter-force beams are adopted in the three-splicing counter-force beam, and the rear ends of the three-splicing counter-force beams are used for being connected with a shoulder pole beam of a tool 20. After the technical scheme is adopted, the utility model has the beneficial effects that the construction cost is effectively reduced, the hoisting workload is reduced, the pre-pressing period is shortened, the pre-pressing difficulty and the safety risk are reduced, the method is simple, and the operation is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge construction, in particular to a preloading device for a reaction beam of a cantilever-cast box girder. Background Technique

[0002] With the continuous expansion of the scale of bridge construction in China, various advanced construction technologies provide quality and safety guarantees for bridge construction. The cantilever casting construction with a hanging basket has become an effective construction method for building large and medium-span bridges due to its good flexibility, strong adaptability, no need for a large number of construction supports and temporary equipment, no impact on navigation and traffic under the bridge, and construction not being affected by seasons and water levels.

[0003] In the construction of continuous beams, the cantilever casting construction with a hanging basket is increasingly adopted, and the preloading of the reaction beam has become an important means to detect the safety in the construction of continuous beam frames. The conventional preloading method uses the load stacking method to test the mechanical properties and safety of the hanging basket formwork, eliminate the non-elastic deformation, measure the elastic deformation amount, and provide a basis for the formwork erection elevation. The commonly used load stacking materials include sand bags filled with sand, steel, precast concrete blocks, water tanks filled with water, etc. However, if there are situations such as high piers, inconvenient horizontal or vertical transportation at the location of the piers, large amount of solid concrete in the box girder, or narrow load stacking operation surface, when using the conventional load stacking preloading, a large amount of preloading materials need to be transported, hoisted, unloaded, etc., with a large workload, long cycle, high safety risk, and high cost. Content of the Utility Model

[0004] The purpose of the utility model is to provide a preloading device for a reaction beam of a cantilever-cast box girder aiming at the defects and deficiencies of the prior art, which can obtain a reaction force by jacking up and anchoring a triple reaction beam, so as to achieve the effect of preloading the hanging basket formwork, solve the problems of complex operation, time-consuming and laborious of the traditional load stacking preloading method, with a simple method and convenient operation. It only takes 2 days to complete the preloading construction of a single hanging basket formwork, solves the problems of long time consumption and high cost of hoisting, holding load and unloading of the load stacking materials in the traditional load stacking preloading construction, eliminates the safety hazards such as collapse of the load stacking materials existing in the load stacking preloading construction, and effectively reduces the safety risk.

[0005] One of the purposes of the utility model is realized by adopting the following technical scheme: a preloading device for a reaction beam of a cantilever-cast box girder, which includes a 0-block, a triple reaction beam anchored on the bottom plate of the 0-block, the high-strength rolled thread steel and bolts anchored to the triple reaction beam, a lifting beam arranged at the rear ends on both sides of the triple reaction beam, jacks arranged on the lower sides of the triple reaction beam on both sides for jacking up, and double-joined I32b transverse distribution beams and double-joined I32b longitudinal distribution beams arranged under the jacks. The triple reaction beam adopts two triple H488 reaction beams, and the rear end of the triple reaction beam is connected by a I20 lifting beam.

[0006] Furthermore, the triple-combined reaction beam is welded by three H488 steel sections.

[0007] Furthermore, the rear anchor area of the triple-combined reaction beam is connected by a 20# I-beam as a crossbeam.

[0008] Furthermore, the double-combined 32b# I-beam longitudinal distribution beam is located below the double-combined 32b# I-beam transverse distribution beam.

[0009] Furthermore, a double-combined 40a# I-beam front lower crossbeam is arranged below the double-combined 32b# I-beam longitudinal distribution beam.

[0010] Furthermore, a 20# I-beam rear cushion beam is arranged between the No. 0 block and the triple-combined reaction beam.

[0011] Furthermore, front steel slings and rear steel suspenders are arranged outside the double-combined 40a# I-beam front lower crossbeam.

[0012] Beneficial effects:

[0013] 1. The construction cost is effectively reduced, the hoisting workload is greatly reduced, the preloading period is shortened, the preloading difficulty and safety risks are reduced, and the problems of complex operation, time-consuming and laborious of the traditional surcharge preloading method are solved. The method is simple and convenient to operate, and has good popularization and application value and economic and social benefits.

[0014] 2. It only takes 2 days to complete the preloading construction of a single hanging basket formwork block, solving the problems of long time consumption and high cost for hoisting, load holding and unloading of the surcharge in traditional surcharge preloading construction.

[0015] 3. The potential safety hazards such as the collapse of the surcharge in surcharge preloading construction are eliminated, and the safety risks are effectively reduced.

[0016] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present utility model. Description of the Drawings

[0017] The present utility model will be further described below in conjunction with the drawings and embodiments;

[0018] Figure 1 It is a side view of a reaction beam preloading device for a cantilever-cast box girder of the present utility model;

[0019] Figure 2 It is a top view of a reaction beam preloading device for a cantilever-cast box girder of the present utility model.

[0020] Legend Explanation:

[0021] 1. Front steel sling; 2. Rear steel suspension rod; 3. Balance beam; 4. Post-pad beam of I20; 5. Jack; 6. Triple-piece reaction beam; 7. Double-piece I32b transverse distribution beam; 8. Double-piece I32b longitudinal distribution beam; 9. Double-piece I40a front lower cross beam. Specific implementation manner

[0022] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the drawings. The function of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0023] Refer to Figure 1 - Figure 2 , a reaction beam preloading device for a cantilever-cast box girder, which includes a 0-block, a triple-piece reaction beam 6 anchored on the bottom plate of the 0-block, the fine-threaded steel bars and bolts anchored by the triple-piece reaction beam 6, balance beams 3 are arranged at the rear ends on both sides of the triple-piece reaction beam 6, jacks 5 are arranged on the lower sides of the upper tops of both sides of the triple-piece reaction beam 6, double-piece I32b transverse distribution beams 7 and double-piece I32b longitudinal distribution beams 8 are arranged on the lower sides of the jacks 5, the triple-piece reaction beam 6 adopts two triple-piece H488 reaction beams, the rear end of the triple-piece reaction beam 6 is used to connect the balance beam 3 of I20, the triple-piece reaction beam 6 is welded by three H488 steel sections, the rear anchor area of the triple-piece reaction beam 6 is connected by the balance beam 3 of I20, the double-piece I32b longitudinal distribution beam 8 is located under the double-piece I32b transverse distribution beam 7, a double-piece I40a front lower cross beam 9 is arranged on the lower side of the double-piece I32b longitudinal distribution beam 8, front steel slings 1 and rear steel suspension rods 2 are arranged on the outer sides of the double-piece I40a front lower cross beam 9, and a post-pad beam 4 of I20 is arranged between the 0-block and the triple-piece reaction beam 6.

[0024] The triple-piece reaction beam 6 adopts triple-piece H488 steel sections. A balance beam 3 is arranged at the reaction point, and double-piece I20b steel beams are arranged at the bottom and supported on the concrete top surface. Two pairs and four φ50 through φ32 HRB400 threaded steel bar reaction holes with a single length of 150 cm are pre-embedded in the bottom plate of the 0-block. Double nuts are used to pull the balance beam 3 and the triple-piece reaction beam 6, and the double-piece I32b steel beams are anchored. The pad beam adopts triple-piece I20b steel beams. A pair of synchronous hydraulic jacks 5 are arranged on the pad beam. When calculating the elastic deformation of the hanging basket preloading, the compression deformation amount of the reaction beam needs to be considered, and this item should be calculated for each section of the hanging basket preloading.

[0025] The preloading triple-spliced reaction beam 6 consists of a 4-meter-long triple-spliced H488 steel section. The double-spliced I20 lifting beam 3 is used for the post-anchoring reaction, and the diameter-32mm high-strength rolled thread steel is anchored. The hydraulic jack 5 is set at the preloading position, and the anchoring reaction point is set at the inner box bottom plate of the 0# block cantilever. Four 5-cm-diameter anchoring holes (single side) are reserved at the preloading position before pouring the 0# block according to the preloading plan. One set of reaction beams is set at each preloading point, and two reaction beams are used for preloading on one side.

[0026] A single reaction beam consists of a longitudinal beam, a lifting beam 3, and a cushion beam. The longitudinal beam is a triple-spliced H488 steel section with a length of 4m. The anchoring is composed of two anchor rods and a lifting beam 3. The lifting beam 3 is made of double-spliced 20b I-beams, and the rear cushion beam is also double-spliced 20b I-beams. The anchor rod passes through the reserved anchor hole of the 0# block and is threaded with φ32 HRB400 threaded steel.

[0027] The working principle of the triple-spliced reaction beam 6: A pair of hydraulic jacks 5 are set at the front support point of the triple-spliced reaction beam 6, a support pier is set in the middle, and the rear part is anchored to the concrete bottom plate of the 0# block through four φ32 high-strength rolled thread steels. The hydraulic jack 5 is controlled by an oil pump to jack up the triple-spliced reaction beam 6. The triple-spliced reaction beam 6 is anchored, and the reaction force is transmitted to the hanging basket suspension system, thus simulating the compression condition of the hanging basket.

[0028] The process of preloading implementation:

[0029] 1. The reaction beam is assembled and welded into shape in the steel bar factory and then hoisted as a whole to the preloading position.

[0030] 2. The reaction beam is extended into the box, and the reaction beam is anchored by using the lifting beam 3 and two φ32 high-strength rolled thread steels. Adjust the position of the reaction beam so that the front support point falls above the jack, and a cushion beam is set below the rear support point to disperse the reaction pressure and avoid damaging the concrete of the 0# block.

[0031] 3. Insert the lifting beam 3 and tighten the nuts of the high-strength rolled thread steel. Pay attention to keeping the horizontal and verticality of the reaction beam to avoid the shear force on the anchor rod.

[0032] 4. Start the oil pump, and the hydraulic jack 5 starts to load. The loading is carried out in stages, which are 25%, 50%, 75%, 100%, and 105% of the total load of the support respectively. After reaching the pressure of each stage, hold the load for 15 minutes. Set an observation point on the bottom plate above the front lower cross beam 9 of each double-spliced I40A. Measure the elevation of each observation point in time after each stage of preloading and make records. After holding the final load for 1 hour, start the oil pump to return the oil and unload the jack 5. After the unloading is completed, measure the elevation of each observation point, calculate the elastic and inelastic deformation of the hanging basket system, and sort out the preloading results.

[0033] 5. The preloading needs to be carried out on both sides simultaneously.

[0034] The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the gist of the present utility model within the scope of knowledge possessed by those of ordinary skill in the relevant art.

Claims

1. A preloading device for the reaction beam of a cantilever-cast box girder, which comprises a 0-block, a triple-section reaction beam (6) anchored on the bottom plate of the 0-block, the fine-threaded deformed steel bars and bolts anchored by the triple-section reaction beam (6), a shoulder beam (3) arranged at the rear ends on both sides of the triple-section reaction beam (6), jacks (5) arranged on the lower sides of the triple-section reaction beam (6) on both sides and pressing upwards, and a double-section I32b transverse distribution beam (7) and a double-section I32b longitudinal distribution beam (8) arranged on the lower sides of the jacks (5), and is characterized in that: The triple-spliced reaction beam (6) adopts two triple-spliced H488 reaction beams, and the rear end of the triple-spliced reaction beam (6) is used to connect with the I20 crossbeam (3).

2. The preloading device for the reaction beam of the cantilever-cast box girder according to claim 1, wherein: The triple-spliced reaction beam (6) is welded by three H488 steel sections.

3. The preloading device for the reaction beam of the cantilever-cast box girder according to claim 1, wherein: The rear anchor area of the triple-spliced reaction beam (6) is connected with the I20 crossbeam (3).

4. A preloading device for a reaction beam of a cantilever-cast box girder according to claim 1, characterized in that: The double-spliced I32b longitudinal distribution beam (8) is located below the double-spliced I32b transverse distribution beam (7).

5. The preloading device for the reaction beam of the cantilever-cast box girder according to claim 1, characterized in that: The double-spliced I40a front lower crossbeam (9) is arranged below the double-spliced I32b longitudinal distribution beam (8).

6. The preloading device for the reaction beam of the cantilever cast box girder according to claim 1, characterized in that: An I20 rear cushion beam (4) is arranged between the 0# block and the triple-spliced reaction beam (6).

7. A preloading device for a reaction beam of a cantilever-cast box girder according to claim 5, characterized in that: The front steel sling (1) and the rear steel hanger (2) are arranged outside the double-spliced I40a front lower crossbeam (9).

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