Bridge incremental launching construction method

Abstract

The application discloses a bridge incremental launching construction method, comprising the following steps: S1, assembling and splicing unit structures of a beam into a segmental beam; S2, butt-joint splicing the segmental beam assembled in the step S1 with an existing beam segment structure into a new beam segment structure on an assembling platform; S3, pushing the new beam segment structure assembled in the step S2 as a whole along the longitudinal direction of the bridge by a distance, so that the new beam segment structure can butt-joint splice a next segmental beam on the assembling platform; and repeating the steps S1 to S3 until all the segmental beams of the bridge are assembled and pushed to target positions; and the track beam of the assembling platform is provided with a first jack, a first pulling device, a first sliding block, a second jack, a second pulling device, a second sliding block, a third jack, a third pulling device and a third sliding block. The application can optimize the structure stress of the incremental launching support under the assembling platform, reduce load concentration and reduce the requirement of the pile foundation of the incremental launching support.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridges, and particularly relates to a bridge incremental launching construction method. BACKGROUND

[0002] The incremental launching method of bridges is rapidly promoted due to the advantages of small construction land occupation, uninterrupted construction process, good overall structure, repeated use of equipment and formwork, no noise in the whole construction process, and faster construction speed. With the gradual improvement of modern incremental launching equipment, the incremental launching method can be used to build long and large bridges with simple equipment, can be used on water, valleys and high piers, and can be used on curved bridges and slope bridges with the same curvature. The application field of the incremental launching method is also becoming wider and wider.

[0003] The incremental launching method can build the structure in segments behind the abutment, assemble the guide beam and the main beam in segments on the assembly platform, push the assembled beam segment structure forward through the walking incremental launching equipment, then assemble and splice the unit structure of the beam on the assembly platform into a new segment beam, and finally form a continuous beam bridge through the segment-by-segment assembly and walking incremental launching.

[0004] The incremental launching construction adopts the circulation incremental launching construction process of jack lifting, jack incremental launching of the main beam, unloading of the main beam on the slide, and pulling back of the jack. In the existing incremental launching method, the slide for supporting the beam bridge or the beam segment structure on the track beam is designed at a fixed position. In actual application, if the length of the assembly platform is limited due to space, the track beam does not have enough length space to add more sets of jacks and slides, and the jacks and slides are required to bear more support reactions. In the construction section with poor foundation, because the support reaction is large, the pile foundation of the incremental launching support under the assembly platform needs to be set to a larger soil penetration depth. This leads to increased construction difficulty and increased construction cost. Therefore, it is urgent to research a more scientific and reasonable construction method. SUMMARY

[0005] The purpose of the present application is to provide a bridge incremental launching construction method for optimizing the structure stress of the incremental launching support under the assembly platform, reducing load concentration, reducing the requirements for the pile foundation of the incremental launching support, reducing construction difficulty, and saving cost.

[0006] The purpose of the present application can be achieved by the following technical solutions.

[0007] A bridge incremental launching construction method, comprising the following steps:

[0008] S1. assembling and splicing the unit structure of the beam into a segment beam;

[0009] S2. butting and assembling the segment beam assembled in the step S1 with the existing beam segment structure on the assembly platform into a new beam segment structure;

[0010] S3. Push the new beam segment structure assembled in step S2 as a whole along the longitudinal direction of the bridge by a distance, so that the new beam segment structure can be butt-jointed and assembled with the next segment beam on the assembling platform;

[0011] S4. Repeat steps S1 to S3 until all segment beams of the bridge are assembled and pushed to the target position; wherein

[0012] In step S2, the assembling platform comprises a track beam and a pushing support, the track beam is provided with a first jack, a first pulling device, a first sliding block, a second jack, a second pulling device, a second sliding block, a third jack, a third pulling device and a third sliding block, the first pulling device is connected to the first jack for driving the first jack to move back and forth on the track beam, the second pulling device is connected to the second jack for driving the second jack to move back and forth on the track beam, the second pulling device is also detachably connected to the first sliding block for driving the first sliding block to move back and forth on the track beam, the third pulling device is connected to the third jack for driving the third jack to move back and forth on the track beam, the third pulling device is also detachably connected to the second sliding block for driving the second sliding block to move back and forth on the track beam, and the track beam is installed on the pushing support;

[0013] In step S3, the beam segment structure of the bridge is moved along the longitudinal direction of the bridge by the first jack, the second jack and the third jack, and the position of the first sliding block and / or the second sliding block is adjusted by moving the first sliding block by the second pulling device and / or moving the second sliding block by the third pulling device, so as to avoid the first sliding block blocking the back and forth movement of the first jack or the second sliding block blocking the back and forth movement of the second jack.

[0014] The sliding block added on the assembling platform can increase the fulcrum position of the pushing beam segment structure and reduce the reaction force on the lower support structure. The length of the assembling platform is limited, and the added sliding block will affect the longitudinal pushing stroke of the beam bridge or its beam segment. The sliding block is set to be movable in the present application, and the position of the sliding block is adjusted by the pulling device according to different working conditions of pushing, so as to optimize the reaction force of the lower support structure, reduce the load concentration, reduce the requirements on the lower support pile foundation, and avoid the influence of the sliding block on the pushing construction process.

[0015] The present application also has the following preferred design:

[0016] The first jack, the second jack and the third jack of the present application are double-acting jacks with hydraulic self-locking function, and jacks with specifications of 500 tons, 800 tons and 1500 tons can be selected according to needs and used in pairs.

[0017] The first pulling device, the second pulling device and the third pulling device of the application are longitudinal pushing oil cylinders driven by hydraulic pressure, and the pushing process can be used to control the stroke of the pushing oil cylinder accurately in cooperation with a displacement sensor.

[0018] The first sliding block is provided with a pin shaft connecting hole for detachable pin connection with the second pulling device, and the second sliding block is provided with a pin shaft connecting hole for detachable pin connection with the third pulling device. When it is necessary to adjust the position of the first sliding block and / or the second sliding block, the first sliding block is pin-connected with the second pulling device, the second sliding block is pin-connected with the third pulling device, and the sliding blocks are moved by means of pulling.

[0019] The first jack, the second jack and the third jack of the application are each provided with a pressure transmitter for monitoring load changes, so as to monitor the load changes of each jack by means of a computer device at the construction site, and to coordinate the load distribution of the jacks in the system.

[0020] The application has the following beneficial effects:

[0021] The sliding block added on the assembling platform of the application not only increases the fulcrum position of the pushing beam segment structure, but also reduces the reaction force on the lower support structure. The sliding block is set as a movable sliding block, and the position of the sliding block is adjusted by means of the pulling device according to different working conditions of pushing, so as to realize the optimization of the reaction force of the lower support structure, reduce load concentration, reduce the requirements on the lower support pile foundation, and avoid the influence of the sliding block on the pushing construction process. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a front view of the assembling platform in the first state of the bridge pushing construction method of the application;

[0023] Figure 2 is Figure 1 an enlarged view of A of the bridge pushing construction method of the application;

[0024] Figure 3 is a front view of the assembling platform in the second state of the bridge pushing construction method of the application;

[0025] Figure 4 is Figure 3 an enlarged view of B of the bridge pushing construction method of the application.

[0026] BRIEF DESCRIPTION OF DRAWINGS: 1-main beam, 2-guide beam, 3-assembling platform, 4-track beam, 5-pushing support, 61-first jack, 62-first pulling device, 63-first sliding block, 71-second jack, 72-second pulling device, 73-second sliding block, 81-third jack, 82-second pulling device, 83-third sliding block. Detailed Implementation

[0027] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, so that those skilled in the art can better understand and implement the technical solution of the present invention.

[0028] like Figures 1 to 4 As shown, a bridge jacking construction method includes the following steps:

[0029] S1. Assemble and splice the beam unit structures into a segmental beam. Figure 1 and Figure 3 The main beam 1 and guide beam 2 are assembled from multiple segment beams.

[0030] S2. On the assembly platform 3, the segmental beam assembled in step S1 is connected with the existing beam segment structure to form a new beam segment structure. In this embodiment, the guide beam 2 is 47 meters long and is assembled from two segmental beams. The main beam 1 is assembled from more than 10 segmental beams according to its total length.

[0031] S3. Push the new beam segment structure assembled in step S2 along the longitudinal direction of the bridge a certain distance so that the new beam segment structure can be connected and assembled with the next segment beam on the assembly platform;

[0032] S4. Repeat steps S1 to S3 until all bridge segments are assembled and pushed to the target position.

[0033] The assembly platform 3 in this embodiment includes a track beam 4 and a jacking bracket 5. The track beam 4 is equipped with a first jack 61, a first pulling device 62, a first slider 63, a second jack 71, a second pulling device 72, a second slider 73, a third jack 81, a third pulling device 82, and a third slider 83. The first pulling device 62 is connected to the first jack 61 to drive the first jack 61 to move back and forth on the track beam 4. The second pulling device 72 is connected to the second jack 71 to drive the second jack 71 to move back and forth on the track beam 4. The second pulling device 72 can also be detachably connected to the first slider 63 to drive the first slider 63 to move back and forth on the track beam 4. The third pulling device 82 is connected to the third jack 81 to drive the third jack 81 to move back and forth on the track beam 4. The third pulling device 82 can also be detachably connected to the second slider 73 to drive the second slider 73 to move back and forth on the track beam 4. The track beam 4 is mounted on the jacking bracket 5.

[0034] In step S3, the beam segment structure of the bridge is moved along the longitudinal direction of the bridge by the first jack 61, the second jack 71 and the third jack 81, and the position of the first sliding block 63 and / or the second sliding block 73 is adjusted by moving the first sliding block 63 through the second pulling device 72 and / or moving the second sliding block 73 through the third pulling device 82, so as to avoid that the first sliding block 63 blocks the forward and backward movement of the first jack 61 or the second sliding block 73 blocks the forward and backward movement of the second jack 71.

[0035] The sliding block added on the assembling platform 3 not only increases the fulcrum position of the pushing beam segment structure, but also reduces the reaction force on the lower support structure. Taking a certain bridge across Huangsha ditch as an example, the land on one side of the bridge is a fish pond section, the foundation is poor, the construction site occupies a limited area, and the length of the assembling platform is also limited. According to the conventional design and construction, the assembling platform uses two sets of pushing mechanisms, and the corresponding jacks, pulling devices and sliding blocks can be regarded as a set of pushing mechanism. According to the comprehensive analysis of various working conditions, the maximum reaction force on the assembling platform 3 is 13000kN. Considering the poor foundation, the pile foundation of the pushing support 5 under the assembling platform 3 needs to reach a depth of 40m. The construction is difficult and the construction cost is high. In the embodiment, one set of pushing mechanism is added, and the maximum reaction force on the assembling platform 3 is reduced to 8400kN, and the pile foundation of the pushing support 5 only needs to reach a depth of 28m. However, because the length of the track beam 4 on the assembling platform 3 is limited, the addition of the jack and the sliding block will affect the longitudinal pushing stroke of the beam bridge or the beam segment thereof. Referring to Figure 3 and Figure 4 , the construction method of walking type pushing is adopted. After the main beam 1 and the guide beam 2 are pushed forward for a distance, the first jack 61 reaches the position of the first sliding block 63, and cannot continue to push forward. In the embodiment, the first sliding block 63 is arranged as a movable sliding block. According to different working conditions of pushing, the first sliding block 63 is connected by the second pulling device 72 and pulled forward for a distance, so that the first sliding block 63 does not block the first jack 61. Similarly, the position of the second sliding block 73 can be adjusted by the third pulling device 82. The embodiment can realize the purpose of optimizing the reaction force of the lower pushing support 5 structure, reducing the load concentration, reducing the requirement for the pile foundation of the lower support, adjusting the position of the sliding block, making the position of the sliding block on the assembling platform 3 as a fulcrum to be scientifically adjusted according to the working conditions, reducing the load concentration, and making the pushing construction process more flexible, avoiding the influence of the sliding block on the pushing construction process.

[0036] As a preferred embodiment:

[0037] The first jack 61, the second jack 71 and the third jack 81 of the present application are double-acting jacks with hydraulic self-locking function. According to the needs, jacks with specifications of 500 tons, 800 tons and 1500 tons can be selected and used in pairs.

[0038] The first pulling device 62, the second pulling device 72 and the third pulling device 82 are longitudinal pushing oil cylinders driven by hydraulic pressure, and the pushing process can be used to control the stroke of the pushing oil cylinder accurately in cooperation with a displacement sensor.

[0039] Specifically, the first sliding block 63 is provided with a pin shaft connecting hole for detachable pin connection with the second pulling device 72, and the second sliding block 73 is provided with a pin shaft connecting hole for detachable pin connection with the third pulling device 82. When it is necessary to adjust the position of the first sliding block 63 and / or the second sliding block 73, the first sliding block 63 is pin-connected with the second pulling device 72, the second sliding block 73 is pin-connected with the third pulling device 82, and the first sliding block 63 or the second sliding block 73 is moved by pulling.

[0040] The first jack 61, the second jack 71 and the third jack 81 are each provided with a pressure transmitter for monitoring the load change, so that the load change of each jack can be monitored by a computer device on the construction site, and the load distribution of the jacks in the system is coordinated.

[0041] The above embodiments are only preferred embodiments of the present application, but cannot be used as a limitation of the present application. Any modification and improvement based on the concept of the present application shall fall within the protection scope of the present application, and the specific protection scope shall be subject to the claims.

Claims

1. A method of incremental launching of a bridge, characterized in that, The method comprises the following steps: S1. Assembling a unit structure of a beam into a segment beam; S2. Butting and assembling the segment beam assembled in the step S1 with an existing beam segment structure into a new beam segment structure on an assembling platform; S3. Pushing the new beam segment structure assembled in the step S2 as a whole along the longitudinal direction of the bridge by a distance, so that the new beam segment structure can butt and assemble a next segment beam on the assembling platform; S4. Circulating the steps S1 to S3 until all the segment beams of the bridge are assembled and pushed to the target position; wherein In the step S2, the assembling platform comprises a track beam and a pushing support, the track beam is provided with a first jack, a first pulling device, a first sliding block, a second jack, a second pulling device, a second sliding block, a third jack, a third pulling device and a third sliding block, the first pulling device is connected with the first jack for driving the first jack to move back and forth on the track beam, the second pulling device is connected with the second jack for driving the second jack to move back and forth on the track beam, the second pulling device is detachably connected with the first sliding block for driving the first sliding block to move back and forth on the track beam, the third pulling device is connected with the third jack for driving the third jack to move back and forth on the track beam, the third pulling device is detachably connected with the second sliding block for driving the second sliding block to move back and forth on the track beam, and the track beam is installed on the pushing support; In the step S3, the beam segment structure of the bridge is moved along the longitudinal direction of the bridge by the first jack, the first pulling device, the second jack, the second pulling device, the third jack and the third pulling device, and the position of the first sliding block and / or the second sliding block is adjusted by moving the first sliding block by the second pulling device and / or moving the second sliding block by the third pulling device, so as to avoid that the first sliding block blocks the back and forth movement of the first jack or the second sliding block blocks the back and forth movement of the second jack.

2. The incremental launching construction method of a bridge according to claim 1, characterized in that: The first jack, the second jack and the third jack are double-acting jacks with hydraulic self-locking function.

3. The incremental launching construction method of a bridge according to claim 2, wherein: The first pulling device, the second pulling device and the third pulling device are hydraulic driving longitudinal pushing cylinders.

4. The incremental launching construction method of a bridge according to claim 3, wherein: The first sliding block is provided with a pin shaft connecting hole for detachable pin connection with the second pulling device, and the second sliding block is provided with a pin shaft connecting hole for detachable pin connection with the third pulling device.

5. The incremental launching method of a bridge according to claim 4, wherein: The first jack, the second jack and the third jack are all provided with a pressure transmitter for monitoring load change.

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