Railway oblique crossing frame structure bridge jacking construction control method

Abstract

The invention relates to the technical field of buildings, and discloses a railway oblique crossing frame structure bridge jacking construction control method which comprises the following steps that the correction angle and the specification of a correction block to be poured are measured and calculated, and a control positioning line is arranged; the method comprises the following steps: prefabricating a backrest and a backrest correction block, prefabricating a frame structure bridge and a frame structure bridge correction block, directly facing the frame structure bridge correction block to the backrest correction block, mounting jacking equipment between the backrest correction block and the frame structure bridge correction block, carrying out jacking test to ensure the performance and carrying out vertical stress, and jacking the frame structure bridge to a specified position. The correcting blocks are additionally arranged at the specific positions of the backrest and the frame structure bridge, the stress state of the frame structure bridge can be adjusted, it is ensured that the position and precision of jacking the frame structure bridge meet the design requirements, the construction period is shortened, and the construction cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of construction technology, and particularly relates to the field of jacking construction of framed bridges, and specifically relates to a method for controlling the jacking construction of a railway skew framed bridge. Background Art

[0002] In recent years, with the acceleration of the modernization process, the urban traffic construction has been developing day by day. However, due to the restriction of urban space, the traffic congestion has become increasingly serious, which has become an important factor restricting the urban economic development and one of the important reasons for the traffic jam. In the jacking construction of railway skew framed bridges, in order to ensure that the position and accuracy of the jacked framed bridge meet the design requirements, some measures are often needed to be taken for correction. In the traditional jacking construction of skew framed bridges, conventional methods such as earth excavation deviation correction, jack deviation correction, and simple support deviation correction are mostly used.

[0003] Among them, earth excavation deviation correction is to adjust the earth excavation amount on both sides of the front end of the framed bridge, so that the resistances on both sides of the framed bridge are different, thereby generating a force that promotes the framed bridge to deviate towards the designed position, achieving the purpose of deviation correction.

[0004] 1. The earth excavation deviation correction method includes single-side over-excavation deviation correction and diagonal over-excavation deviation correction ① Single-side over-excavation deviation correction: When the framed bridge deviates to one side, appropriately over-excavate on the other side of the deviation direction to reduce the resistance on that side. Under the action of the jacking force, the framed bridge deviates towards the over-excavated side and gradually returns to the designed position. For example, if the framed bridge deviates to the right, over-excavate on the left side.

[0005] ② Diagonal over-excavation deviation correction: For the situation where the framed bridge shows torsional deviation, the diagonal over-excavation method can be adopted. That is, over-excavate at one corner of the front end of the framed bridge, and at the same time appropriately under-excavate at the other diagonal corner, and use the resistance difference on both sides to generate a torsional moment to correct the torsional deviation of the framed bridge.

[0006] 2. Jack deviation correction: Generally, multiple jacks are arranged at the rear end of the framed bridge, usually symmetrically distributed along the width direction of the bridge. According to the size and weight of the framed bridge, as well as the specific requirements of the jacking construction, determine the number, type, and arrangement spacing of the jacks to ensure that sufficient and uniform jacking force can be provided.

[0007] ① Single-side jacking force adjustment deviation correction: When the framed bridge deviates to one side, reduce the jacking force of the jacks on the same side as the deviation direction, or increase the jacking force of the jacks on the other side, so that the framed bridge is subjected to a thrust towards the other side, thereby achieving deviation correction. For example, if the framed bridge deviates to the left, appropriately reduce the jacking force of the left-side jacks and at the same time increase the jacking force of the right-side jacks.

[0008] ② Partial jacking force adjustment for deviation correction: For the local deviation or torsion of the box culvert bridge, the jacks at specific positions can be adjusted individually. For example, if there is a deviation on the right side of the front end of the box culvert bridge, the jacking force of the jack on the right side of the front end can be increased, and at the same time, the jacking force of the jacks at other relevant positions can be appropriately reduced to correct the local deviation.

[0009] The above methods all require adjustment in multiple directions, and the control accuracy of the axis and elevation deviations generated during the jacking process is limited, making it difficult to cope with the construction deviation problems brought by complex geological conditions and large skew angles. To solve the above problems, the present invention proposes a method for controlling the jacking construction of a railway skew box culvert bridge. Summary of the Invention

[0010] The present invention provides a method for controlling the jacking construction of a railway skew box culvert bridge to solve a series of problems in the current jacking construction process of the railway skew box culvert bridge, such as the need to take corrective measures to ensure that the position and accuracy of the jacked box culvert bridge meet the design requirements, but these methods all require adjustment in multiple directions.

[0011] The present invention is implemented as follows: The present invention provides a method for controlling the jacking construction of a railway skew box culvert bridge. This method focuses on the description of the correction method, and the jacking construction methods of the remaining box culvert bridges are the same as those in the prior art and will not be elaborated. Referring to the "Code for Construction of Railway Bridges and Culverts" and other relevant jacking construction guidelines, the method includes the following steps: S1. Construction preparation Calculate the correction angle and the specifications of the correction blocks to be poured according to the construction site, and set out the control positioning lines.

[0012] S2. Prefabrication of the backrest and the backrest correction blocks Embed the main reinforcement and distribution reinforcement of the backrest correction blocks, and weld and fix the rectangular steel plates. The length and width of the rectangular steel plates are both 1.2 m, and the thickness is 20 mm; support and reinforce the formwork. The adjacent two backrest correction blocks are 0.45 m apart in the jacking direction. The backrest correction blocks and the backrest are poured with C35 concrete synchronously to form an integral backrest, and cured to the design strength.

[0013] S3. Prefabrication of the box culvert bridge and the box culvert bridge correction blocks Embed the main reinforcement and distribution reinforcement of the box culvert bridge correction blocks on the side of the bottom plate facing the backrest. The distance between adjacent two box culvert bridge correction blocks is equal to the distance between adjacent two backrest correction blocks. The adjacent two box culvert bridge correction blocks are 0.45 m apart in the jacking direction, that is, the adjacent two backrest correction blocks and the adjacent two box culvert bridge correction blocks are all staggered 0.45 m front and back.

[0014] The frame bridge correction block and the rear backrest correction block are arranged in a centrally symmetrical manner. The height of the frame bridge correction block and the rear backrest correction block are both 1.2m. The horizontal cross-section of the frame bridge correction block and the rear backrest correction block is a right triangle. The angle between the hypotenuse and the right angle is the same as the oblique angle, that is, the load-bearing surface of the frame bridge bottom plate and the installation surface of the jacking equipment of the rear backrest are corrected to the jacking direction.

[0015] The frame bridge correction block is directly opposite to the rear backrest correction block, and the vertical spacing between the directly opposite frame bridge correction block and the rear backrest correction block is 2m. Reinforced wooden formwork is supported at the frame bridge correction block, and C40 concrete is poured simultaneously on the frame bridge correction block and the bottom plate to form a whole bottom plate, which is then cured to the designed strength.

[0016] S4. Equipment Installation A 25t crane is used to unload the jacking equipment between the rear backrest correction block and the frame bridge correction block, and the jacking equipment is evenly installed between the two opposite sides. The equipment is connected and its performance is checked to ensure that vertical force is applied to the frame bridge during jacking.

[0017] S5, test top Start the jacking equipment and test jacking for 50cm. Check and confirm the performance of the equipment again to ensure that the performance is stable and good and that it is subjected to vertical force.

[0018] S6, jacking construction of frame bridge During the jacking process, the elevation and axis direction are remeasured after each jacking. If any deviation occurs, it is adjusted in time until the jacking reaches the specified position. The allowable deviation of the jacking elevation is ≤±50mm, and the allowable deviation of the axis is ≤±50mm.

[0019] S7. Finishing work Remove the jacking equipment, backfill the working pit, and restore the ground facilities.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present application provides a control method for jacking construction of a railway oblique frame bridge. By adding correction blocks at specific positions of the rear backrest and the frame bridge, the stress state of the frame bridge can be adjusted to ensure that the position and accuracy of the jacked frame bridge meet the design requirements. The use of correction blocks avoids direct contact between the jacking equipment and the bottom plate of the frame bridge and causes damage, which plays a good protective role on the frame bridge, shortens the construction period, and reduces construction costs. During the jacking construction process, there is no need to interrupt the operation of the existing line, reducing interference with transportation.

[0021] According to calculations, the correction block was constructed simultaneously with the backrest and the frame bridge bottom plate. One side of the cross section utilized the backrest and the frame bridge bottom plate, saving 101m of formwork and wood. 2 The overall template installation period was shortened by 1 day. By adding correction blocks, the jacking construction was shortened by 2 days compared to the planned period.

[0022] The method is simple to operate and easy to construct, and can effectively solve the technical problems of precision control such as frame bridge axis deviation and elevation in the jacking construction of railway skew frame bridges. It can quickly adjust the jacking deviation, reduce the rework and adjustment time caused by excessive deviation, improve construction efficiency, ensure the quality of engineering construction, and reduce construction costs. The method can be widely used in the jacking construction of various frame bridges such as railways, highways, and municipal engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 Arrange a large-scale drawing for the correction block.

[0025] In the figure: 1-frame bridge correction block, 2-rear backrest correction block, 3-rear backrest, 4-rectangular steel plate, 5-bottom plate, 6-opening frame, 7-frame bridge. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are described in detail below.

[0027] A construction control method for jacking of railway oblique frame bridges was applied in the railway underpass oblique frame bridge project of the S312 Yongkang to Wuyi Highway Reconstruction Project (Wuyi Section), which effectively ensured the jacking accuracy of the frame bridge and achieved good results. Figures 1 - 2 As shown, the following steps are included: S1. Construction preparation Excavate the working pit, carry out precipitation, slope support and foundation treatment to ensure that the bearing capacity of the pit bottom meets the requirements. Calculate the correction angle and the specifications of the correction blocks to be poured according to the construction site, and lay out the control positioning line. Then, according to the requirements of the design drawings, lay out the outlines of the opening frame 6, frame bridge 7 and the rear back correction block; simultaneously lay out the position for installing the steel plate on the rear back correction block; accurately lay out the jacking direction and control line according to the design coordinates and elevation; at the same time, it should be noted that during the jacking process, regular measurement and verification should be carried out to ensure the jacking accuracy.

[0028] S2, backrest 3, backrest correction block 2 prefabrication Process the steel bars of the rear backrest correction block 2 as required, and pre-embed the main bars and distribution bars of the rear backrest correction block 2. Note that the adjacent rear backrest correction blocks 2 are staggered by 0.45m front and back, and recheck the spacing after completion.

[0029] Weld and fix the rectangular steel plate 4. The length and width of the rectangular steel plate 4 are both 1.2 m, and the thickness is 20 mm. Support and reinforce the formwork with steel pipes and tie bolts to make the formwork firmly reinforced. Pour C35 concrete for the backrest correction block 2 and the backrest 3 synchronously to form the integral backrest. Cure it to the designed strength. It should be noted that during the concrete pouring process, pay attention to vibrating it densely. After the pouring is completed, wait for the concrete to reach the final setting, then remove the formwork in time and carry out sprinkler curing.

[0030] S3. Prefabricate the frame bridge and the frame bridge correction block 1 Embed the main reinforcement and distribution reinforcement of the frame bridge correction block 1 on one side of the bottom plate 5 facing the backrest 3. Similarly to the backrest correction block 2, the distance between two adjacent frame bridge correction blocks 1 is equal to the distance between two adjacent backrest correction blocks 2. The distance between two adjacent frame bridge correction blocks 1 along the jacking direction is 0.45 m, that is, two adjacent backrest correction blocks 2 and two adjacent frame bridge correction blocks 1 are both staggered 0.45 m front and back.

[0031] The frame bridge correction block 1 and the backrest correction block 2 are arranged in central symmetry. The heights of the frame bridge correction block 1 and the backrest correction block 2 are both 1.2 m. The horizontal cross-section of the frame bridge correction block 1 and the backrest correction block 2 is a right triangle. In this embodiment, the lengths of the frame bridge correction block 1 and the backrest correction block 2 are both 1.5 m, that is, the lengths of the two right-angled sides of the right triangle are 1.5 m and 0.45 m respectively.

[0032] The frame bridge correction block 1 is directly opposite to the backrest correction block 2, and the vertical distance between the directly opposite frame bridge correction block 1 and the backrest correction block 2 is 2 m. Support and reinforce the formwork at the frame bridge correction block 1. Pour C40 concrete for the frame bridge correction block 1 and the bottom plate 5 synchronously to form the integral bottom plate. Cure it to the designed strength. Set a lubricating layer under the bottom plate 5. The lubricating layer includes engine oil, plastic film and talcum powder to reduce the jacking resistance.

[0033] S4. Equipment installation Use a 25t crane to hoist and unload the jacking equipment between the backrest correction block 2 and the frame bridge correction block 1, and evenly install the jacking equipment between their directly opposite sides. The jacking equipment is existing equipment. The jacking equipment includes a hydraulic control system, guide rails, 500t jacks, 7.5m jacking pipes, 4m jacking pipes, 2m jacking irons, 1m jacking irons, 0.5m jacking irons. Connect the equipment and check its performance to ensure that the frame bridge 7 is vertically stressed during jacking.

[0034] S5. Trial jacking Start the jacking equipment to conduct a trial jacking of 50 cm, and check and confirm the equipment performance again to ensure that the performance is stable and good and the vertical stress is ensured.

[0035] S6. Frame bridge jacking construction The jacking shall be carried out in stages. During each jacking process, the elevation and axis direction shall be remeasured. If any deviation occurs, it shall be adjusted in time until the jacking reaches the specified position. The allowable deviation of the jacking elevation shall be ≤±50mm, and the allowable deviation of the axis shall be ≤±50mm.

[0036] 1. Before jacking, lay out the central axis of the frame bridge and extend the central axis to the leveling layer. At the same time, lay out the edge lines of the walls on both sides on the leveling layer, and draw a 20cm control line with the right wall line. Use a total station and level to measure and record the direction (central axis) and elevation (four corners) for each jacking process.

[0037] 2. During the jacking process, the axis and elevation of the frame bridge should be observed for each jacking distance, and timely measures should be taken to correct any deviations. The performance of the jacking equipment should be checked and confirmed again to ensure stable and good performance. Jacking should be carried out during the intervals between trains. It is strictly forbidden to jack when the train passes through the line. During the jacking period, special personnel must be assigned to monitor and be responsible for observing, rectifying deformation and maintaining the line to ensure driving safety.

[0038] S7. Finishing work Remove the jacking equipment, backfill the working pit, and restore the ground facilities.

[0039] According to calculations, the correction block was constructed simultaneously with the backrest and the frame bridge bottom plate. One side of the cross section utilized the backrest and the frame bridge bottom plate, saving 101m of formwork and wood. 2 The overall template installation period was shortened by 1 day. By adding correction blocks, the jacking construction was shortened by 2 days compared to the planned period.

[0040] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention may have various deformations and changes. Any modifications, improvements and equivalent substitutions made within the concept and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the jacking construction of a railway oblique frame bridge, characterized in that: The following steps are involved: S1. Construction preparation Calculate the correction angle and the specifications of the correction blocks to be poured according to the construction site, and lay out the control positioning line; S2, backrest (3), backrest correction block (2) prefabrication The main reinforcement and distribution reinforcement of the rear backrest correction block (2) are embedded, and the rectangular steel plate (4) is welded and fixed; a reinforced wooden formwork is supported, and the rear backrest correction block (2) and the rear backrest (3) are simultaneously poured with C35 concrete to form a rear backrest as a whole, and then cured to the designed strength; S3, frame bridge, frame bridge correction block (1) prefabrication The main reinforcement and distribution reinforcement of the frame bridge correction block (1) are embedded on the side of the bottom plate (5) facing the rear backrest (3), the frame bridge correction block (1) is directly opposite to the rear backrest correction block (2), and the vertical spacing between the directly opposite frame bridge correction block (1) and the rear backrest correction block (2) is 2m, and a reinforced wooden formwork is supported at the frame bridge correction block (1). The frame bridge correction block (1) and the bottom plate (5) are simultaneously poured with C40 concrete to form a bottom plate as a whole, and are cured to a designed strength; S4. Equipment Installation The jacking equipment is hoisted between the rear backrest correction block (2) and the frame bridge correction block (1), and the jacking equipment is evenly installed between the two opposite sides, and the equipment is connected and its performance is checked to ensure that the frame bridge (7) is vertically stressed during jacking; S5, test top Start the jacking equipment and test jacking 50cm, and check and confirm the equipment performance again to ensure that the performance is stable and good and the vertical force is applied; S6, jacking construction of frame bridge During the jacking process, the elevation and axis direction are re-measured for each jacking. If there is any deviation, it is adjusted in time until the jacking reaches the specified position. The allowable deviation of the jacking elevation is ≤±50mm, and the allowable deviation of the axis is ≤±50mm. S7. Finishing work Remove the jacking equipment, backfill the working pit, and restore the ground facilities.

2. A method for controlling jacking construction of a railway oblique frame bridge according to claim 1, characterized in that: The spacing between two adjacent frame bridge correction blocks (1) is equal to the spacing between two adjacent rear backrest correction blocks (2).

3. A railway oblique frame bridge jacking construction control method according to claim 2, characterized in that: The difference between two adjacent rear backrest correction blocks (2) along the jacking direction is 0.45 m, and the difference between two adjacent frame bridge correction blocks (1) along the jacking direction is 0.45 m.

4. A railway oblique frame bridge jacking construction control method according to claim 1, characterized in that: The frame bridge correction block (1) and the rear backrest correction block (2) are centrally symmetrically arranged.

5. A railway skew frame bridge jacking construction control method according to claim 3, characterized in that: The frame bridge correction block (1) and the rear backrest correction block (2) are both 1.2 m in height and 1.5 m in length.

6. A railway oblique frame bridge jacking construction control method according to claim 1, characterized in that: In S2, the rectangular steel plate (4) has a length and width of 1.2 m and a thickness of 20 mm.

7. A railway oblique frame bridge jacking construction control method according to claim 1, characterized in that: In S4, a 25t crane is used to lift and install the jacking equipment.

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