Construction method of steel-concrete composite section of bridge deck crane based on forward movement of temporary side span supports

Abstract

This invention relates to the field of bridge construction technology, and particularly to a construction method for steel-concrete composite sections using a bridge deck crane based on the forward movement of temporary supports for side spans. The method includes erecting temporary piers, a crane assembly platform, a hoisting and positioning platform, and temporary supports for crane relocation; using a tower crane to lift the slewing crane components to the crane assembly platform for installation; hoisting the No. 0 segment of the main steel beam and its corresponding crossbeams to the hoisting and positioning platform; pouring, curing, and demolding the concrete for the steel-concrete composite section, as well as prestressing tensioning and grouting; hoisting the small longitudinal beams of the No. 0 segment; moving the slewing crane forward to hoist the No. 1 segment of the steel beam; installing and initially tensioning the stay cables of the No. 1 segment; hoisting the bridge deck panels for the No. 0 and No. 1 segments of the steel beam, and pouring, curing, and secondary tensioning of the cast-in-place bridge deck panels and wet joints. This invention changes the complex process of steel beam installation, which previously relied on the cantilever scaffolding at the crossbeam of the pylon and the coordinated operation of the tower crane, simplifying the construction process, reducing equipment requirements, and improving the overall coordination and economy of the project.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for constructing a steel-concrete composite section of a bridge deck crane based on the forward movement of temporary supports for the side spans. Background Technology

[0002] The installation of steel main beams for large bridges in mountainous areas is affected by multiple factors such as transportation conditions and site limitations, and cantilever hoisting is usually carried out using a bridge deck rotary crane.

[0003] The steel main beam hoisting is generally carried out by cantilever assembly from the tower to the main span side. Among them, the steel main beam of section 0 in the tower area serves as the assembly platform for the bridge deck slewing crane. Due to the narrow site, large hoisting equipment cannot be introduced for its installation. The lifting capacity of the tower crane currently used is limited. Therefore, the conventional process is to erect a cantilever scaffold at the crossbeam position on the tower to install the steel main beam of section 0 in the tower area and complete the temporary consolidation of the tower and beam.

[0004] Subsequently, the bridge deck rotary crane was used in conjunction with the tower crane to lift the bridge deck onto the No. 0 steel main beam for assembly. After assembly, test runs and trial lifts were conducted to verify the process, and finally, the bridge deck rotary crane was used for the cantilever assembly of the No. 1 steel main beam.

[0005] In the above construction methods, the installation of the No. 0 steel main beam requires the coordinated operation of the cantilever gantry and tower crane at the crossbeam position on the pylon. The process is complex, and the slewing crane must be assembled on the already installed No. 0 steel main beam in the tower area. The various construction links, including the assembly of the slewing crane and the assembly of the No. 0 steel main beam, are independent of resources and lack coordination. Summary of the Invention

[0006] This invention provides a construction method for steel-concrete composite sections of bridge deck cranes based on the forward movement of temporary supports on the side spans. It is applied to the construction of hybrid beam cable-stayed bridges, omitting the construction step of erecting cantilever scaffolds at the crossbeam position on the pylon in the prior art. The assembly of the slewing crane is completed through temporary supports and tower cranes, which simplifies the construction process and reduces equipment requirements.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The construction method of bridge deck crane steel-concrete composite section based on the forward movement of temporary supports in the side spans is applied to the construction of hybrid beam cable-stayed bridges, including:

[0009] Temporary supports are erected on both sides of the tower, and hoisting and positioning platforms and crane assembly platforms are erected on the temporary supports on the main span side and the side span side, respectively. Temporary support frames for moving the crane are also erected between the crane assembly platforms and the hoisting and positioning platforms.

[0010] The slewing crane components on the bridge deck are lifted by a tower crane at the pier base and transported to the crane assembly platform for installation.

[0011] After the rotary crane is assembled, it is moved to the corresponding position on the hoisting platform and anchored in place using the temporary hoisting support.

[0012] A steel beam support frame is erected and preloaded on the temporary piers on the main span side;

[0013] Hoisting of steel main beam segment 0;

[0014] Hoist the steel crossbeam corresponding to section 0 of the main steel beam;

[0015] The concrete pouring, curing and formwork removal of the steel-concrete composite section are carried out, and the longitudinal and transverse prestressing of the steel-concrete composite section is tensioned and grouted.

[0016] The small longitudinal beams corresponding to section 0 of the main steel beam were hoisted.

[0017] Move the rotary crane forward to the corresponding position of section 0 of the steel main beam and anchor it in place;

[0018] The steel main beam section 1 and its corresponding steel crossbeams and longitudinal beams were hoisted.

[0019] The stay cables of section 1 of the main steel beam were installed and initially tensioned.

[0020] The bridge deck panels for sections 0 and 1 of the main steel beams were hoisted.

[0021] The cast-in-place bridge deck and wet joints of the steel main beam from section 0 to section 1 were poured, cured, and subjected to secondary tensioning.

[0022] Furthermore, after the rotary crane is anchored in place, the crane assembly platform and temporary relocation support are removed.

[0023] Furthermore, the bottom of the rotary crane includes a crane support bracket, which includes a front crossbeam and a rear crossbeam arranged in parallel. The hoisting and positioning platform includes a support crossbeam connected to the temporary support pier, and the front crossbeam moves to the top of the support crossbeam and is positioned thereon.

[0024] Furthermore, after the slewing crane is assembled and before it is moved, a no-load operation test, a static load test, and a slewing rotational load test are conducted.

[0025] Furthermore, the no-load operation test includes:

[0026] Start the lifting mechanism of the slewing crane and lift the hook to run back and forth vertically along the boom several times without load. During the operation, at least the phenomenon of wheel slippage and jamming, the starting and braking conditions, and the sensitivity of the switch action should be judged.

[0027] In addition, the slewing mechanism of the slewing crane is started to rotate 360 ​​degrees and the boom is simultaneously rotated vertically back and forth several times. During operation, the starting and braking status, as well as the sensitivity of the switch action, are judged at least.

[0028] Furthermore, the no-load operation test also includes:

[0029] During the test, the current curves of the lifting mechanism motor and the slewing mechanism motor of the rotary crane were monitored in real time using sensors;

[0030] Record the current curve under undisturbed conditions, calculate the average steady-state current as a reference value, and set a reasonable range for the fluctuation threshold.

[0031] Accelerometers are installed at the designated nodes of the temporary supports on the side span to synchronously collect vibration frequencies during the test.

[0032] When the current fluctuation exceeds the threshold, the vibration spectrum at the corresponding time is extracted. If the dominant vibration frequency in the vibration spectrum overlaps with the natural frequency of the temporary support, it is determined that there is a risk of resonance.

[0033] Based on the assessment of resonance risk, the hoisting speed of the rotary crane is adjusted.

[0034] Furthermore, during the operation of the slewing crane, the current curves of the lifting mechanism motor and the slewing mechanism motor of the slewing crane are monitored in real time. When the resonance risk is detected, a speed adjustment command is triggered. Specifically, upon the first trigger, the hoisting speed is reduced to 80% of the original speed, and upon the second trigger, the hoisting speed is further reduced to 50% of the original speed, and an alarm is issued.

[0035] Further, the hoisting of the No. 0 section of the main steel beam is carried out, including:

[0036] The center positioning line of the main steel beam is laid out on the steel beam support;

[0037] When the 0th segment of the main steel beam is hoisted to a distance of a set value from the top surface of the steel beam support, the plane position is located by aligning with the center line of the main steel beam, and then it is lowered at a set speed.

[0038] The elevation of the top surface of section 0 of the main steel beam was measured, and steel plates were adjusted and filled into the bottom surface of section 0 of the main steel beam based on the measurement results.

[0039] Further, the steel crossbeams corresponding to segment 0 of the main steel beam are hoisted, including:

[0040] The steel beam is divided into three parts along its length and stored at the bottom of the pier.

[0041] The first part of the steel beam away from the tower crane is lifted by the rotary crane, and the second and third parts of the steel beam are lifted sequentially by the tower crane;

[0042] After each part is hoisted, it is aligned and connected with the main steel beam, and the bottom is filled with adjusting steel plates between the distribution beam of the steel beam support.

[0043] Furthermore, it also includes:

[0044] The longitudinal and transverse prestressing tensioning, grouting, and curing of the bridge deck of steel main beams No. 0 and No. 1 sections were carried out;

[0045] The stay cables of section 1 of the main steel beam were tensioned a second time.

[0046] The technical solution of this invention can achieve the following technical effects:

[0047] In this invention, the complex process of installing the steel main beam, which relies on the cantilever gantry and tower crane working together at the position of the crossbeam on the cable tower, is changed, simplifying the construction process and reducing equipment requirements.

[0048] This invention is applied to the construction of hybrid beam cable-stayed bridges. The structural characteristics of hybrid beam cable-stayed bridges are that the side spans use concrete main beams, while the main span uses steel main beams, including steel main beams, steel crossbeams, and small longitudinal beams. The construction of the concrete main beams in the side spans typically employs a segmented cast-in-place construction method using temporary pile foundations, steel pipe piers, and Bailey bridge scaffolding systems. In the construction of the steel main beams in section 0 of the tower area, this invention innovatively adopts a scaffolding system for side span construction, using temporary supports on temporary piers to facilitate the assembly and installation of the rotating crane on the bridge deck.

[0049] This invention directly uses the bridge deck's rotary crane to assemble and install the No. 0 segment of the main steel beam, simultaneously completing processes such as reinforcing steel, prestressed tendons, and anchorage systems. This simplifies the process, reduces equipment requirements, and directly utilizes the support system from the side span concrete main beam construction to erect the assembly platform, eliminating the need for additional cantilever scaffolding, thus saving time and costs. By reusing the side span construction support system, it achieves seamless integration of crane assembly, No. 0 segment steel beam installation, and subsequent No. 1 segment construction, improving the overall project coordination and economy. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1The flowchart shows the construction method of the steel-concrete composite section of the bridge deck crane based on the forward movement of the temporary support of the side span;

[0052] Figure 2 This is a schematic diagram showing the installation of temporary supports, temporary moving brackets, crane assembly platforms, and hoisting positioning platforms relative to the cable tower.

[0053] Figure 3 for Figure 2 Top view;

[0054] Figure 4 for Figure 2 Side view;

[0055] Figure 5 A schematic diagram showing the completed assembly of the rotary crane;

[0056] Figure 6 This is a schematic diagram showing the completion of the hoisting of steel main beam segment 0.

[0057] Figure 7 This is a schematic diagram showing the completed hoisting of steel main beam section 1 and its corresponding steel crossbeams and longitudinal beams;

[0058] Figure 8 This is a flowchart of the hoisting process for section 0 of the main steel beam.

[0059] Figure 9 This is a flowchart of the hoisting process for the steel crossbeam corresponding to section 0 of the main steel beam.

[0060] Figure label:

[0061] 1. Temporary support pier; 2. Temporary support for machine relocation; 3. Crane assembly platform; 4. Lifting and positioning platform; 41. Support pier crossbeam; 5. Cable tower; 6. Slewing crane; 7. Tower crane; 8. Steel main beam section 0; 9. Steel main beam section 1; 10. Steel crossbeam; 11. Small longitudinal beam. Detailed Implementation

[0062] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0063] Example 1

[0064] like Figures 1-7 As shown, the construction method of the steel-concrete composite section of the bridge deck crane based on the forward movement of the temporary support of the side span is applied to the construction of a hybrid beam cable-stayed bridge, including:

[0065] S1: See Figures 2-4Temporary supports 1 are erected on both sides of the tower 5, and hoisting and positioning platforms 4 and crane assembly platforms 3 are erected on the temporary supports 1 on the main span side and the side span side, respectively. Temporary support 2 for moving the crane is erected between the crane assembly platform 3 and the hoisting and positioning platform 4.

[0066] Temporary support pier 1 is specifically erected on the side of the bridge with the larger chainage along the cable tower 5. It can be a steel pipe pier. The verticality and planar position of the steel pipe need to be controlled. In this embodiment, the verticality of the steel pipe is required to be no more than 1%, and the deviation of the planar axis is required to be no more than 5cm. The planar position of the included load-bearing beams and distribution beams is also controlled.

[0067] S2: The pier-bottom tower crane 7 is used to lift the disassembled components of the bridge deck slewing crane 6 to the crane assembly platform 3 for installation. Before this step, the slewing crane 6 needs to be selected. The selection is based on the specific lifting method, the weight, size, and position of the steel main beam, bridge deck, and other components to be lifted. The slings also need to be selected according to the single rope tension requirements, paying attention to the minimum breaking strength.

[0068] S3: After the slewing crane 6 is assembled, it is moved to the corresponding position on the hoisting platform 4 using the temporary hoisting support 2 and anchored in place. The anchoring is completed as follows: Figure 5 As shown;

[0069] S4: Erect a steel beam support on the temporary support 1 on the main span side and preload it; the erection of the steel beam support in this step can be completed in the above steps, or after each step, both of which are within the protection scope of this invention.

[0070] S5: As Figure 6 As shown, the steel main beam segment 0 (8) is being hoisted; this step can be achieved using the bridge deck rotary crane (6).

[0071] S6: Hoist the steel crossbeam 10 corresponding to the steel main beam segment 8; similarly, this step can be achieved by the bridge deck slewing crane 6. Before this step is implemented, if there is any interference between the temporary support 1 and the support rods or other structures between the hoisting and positioning platform 4, they must be removed first.

[0072] S7: Concrete pouring, curing, and formwork removal are carried out for the steel-concrete composite section, and the longitudinal and transverse prestressing of the steel-concrete composite section is tensioned and grouted. Specifically, the steel-concrete composite section supports, reinforcing bars, prestressing, and embedded parts must first be constructed and installed. The formwork for the side span concrete main beam support is then installed, and concrete is poured and cured until the concrete strength reaches the design requirements. After that, the formwork is removed, and the longitudinal and transverse prestressing of the steel-concrete composite section is tensioned and grouted.

[0073] S8: Hoist the small longitudinal beam 11 corresponding to segment 8 of the main steel beam;

[0074] S9: Move the rotary crane 6 forward to the corresponding position of section 0 of the steel main beam and anchor it in place;

[0075] S10: As Figure 7 As shown, the steel main beam segment 19 and the corresponding steel crossbeam 10 and small longitudinal beam 11 are hoisted; during the implementation process, the steel main beam segment 08 and steel main beam segment 19 also need to be spliced, specifically including top splicing through the top plate splicing plate, bottom splicing through the bottom plate splicing plate, and side splicing through the web plate splicing plate.

[0076] S11: Install and initially tension the 9 stay cables of section 1 of the main steel beam;

[0077] S12: Hoist the bridge deck of steel main beam segments 0 and 1; rotate the slewing crane 6 to the bridge deck installation position, slowly lower the bridge deck, and precisely adjust its position; to ensure that the longitudinal and transverse prestressed ducts of the bridge deck can be accurately aligned, longitudinal and transverse reference lines are set with the template as a reference during the prefabrication of the bridge deck, and the reference lines of adjacent bridge decks are ensured to be on a straight line during installation; at the same time, since the overlap area between the bridge deck and the steel crossbeam 10 is relatively small, to ensure safety, the bridge deck must be welded and fixed to the adjacent steel components immediately after fine adjustment;

[0078] S13: Casting, curing and secondary tensioning of the cast-in-place bridge deck and wet joints of the steel main beam from section 0 to section 1; the supports and formwork of the cast-in-place bridge deck are preferably installed during the hoisting of the bridge deck of the steel main beam from section 0 to section 1, and formwork installation, rebar installation and prestressed tendon installation are required.

[0079] The pouring sequence for wet joint concrete is as follows: first, pour the longitudinal joints from the cantilever end towards Tower 5, then pour the transverse joints from the inside out. Before constructing the wet joints, clean the joints, straighten the bridge deck reinforcement, and weld the reinforcement to enhance the tensile strength of the joints. Single-sided welding is used to connect both the longitudinal and transverse reinforcement of the bridge deck. Pour the concrete according to the bridge deck prefabrication process. After the wet joints are poured, before initial setting, the surface should be roughened strictly according to requirements.

[0080] This invention is applied to the construction of hybrid beam cable-stayed bridges, characterized by concrete main beams in the side spans and steel main beams in the main span. The construction of the concrete main beams in the side spans typically employs a segmented cast-in-place construction system using temporary pile foundations, steel pipe piers, and Bailey bridge scaffolding. The construction of each segment of the concrete main beam can be synchronized with the construction of each segment of the steel main beam in the main span according to a set schedule. In the construction of the steel main beam in segment 0 of the tower area, this invention innovatively adopts a scaffolding system for side span construction, using a modular assembly and installation method for the rotating crane 6 on the bridge deck.

[0081] The assembly of the slewing crane 6 on the bridge deck is completed on the temporary support 1 behind the tower. After assembly, it is moved forward to the designated position in the tower area via the temporary support 2 for trial operation and lifting. Subsequently, the slewing crane 6 is used to install the steel main beam of section 0 in the tower area. After the construction of section 0 is completed, the bridge deck slewing crane 6 is moved forward to the steel main beam of section 0 to continue the assembly of the steel main beam of section 1. The steel main beams of section 2 and other sections in front of the side span can be installed using the slewing crane 6 and the same lifting method. Specifically, after the slewing crane 6 is in the designated position of section N, the steel main beam of section N+1 can be lifted, including the steel main beam, steel crossbeam 10 and small longitudinal beam 11; the corresponding stay cables of section N+1 are hung and initially tensioned, and the bridge deck is installed; then the stay cables are tensioned a second time. After completion, the slewing crane 6 is moved forward to the N+1 segment of the main steel beam, and the above work is repeated. Ultimately, the steel main beam of the steel-concrete composite section and the concrete main beam of the side span can be cast in one go.

[0082] Example 2

[0083] In this embodiment, more detailed construction details are provided based on Embodiment 1.

[0084] As a preferred embodiment of the above, after the rotary crane 6 is anchored in place, the crane assembly platform 3 and the temporary relocation support 2 are removed.

[0085] As a preferred embodiment of the above, the bottom of the rotary crane 6 includes a crane support bracket, which includes a front crossbeam and a rear crossbeam arranged in parallel. The hoisting and positioning platform 4 includes a support crossbeam 41 connected to the temporary support 1. The front crossbeam moves to the top of the support crossbeam 41 and is positioned.

[0086] During implementation, the crane support bracket is installed on the hoisting and positioning platform 4 on the side of the span. After installation, wooden boards can be laid on the upper surface of the front and rear crossbeams to facilitate the movement of construction personnel. The slewing crane 6 needs to be equipped with a track for position movement. Therefore, it is necessary to measure and mark the lines above the front and rear crossbeams at the same time to make the positioning lines of the track. The tower crane 7 is used to lift the track to the marked position and anchor it to the front and rear crossbeams.

[0087] In this embodiment, the crane support frame of the slewing crane 6 includes, in addition to the front and rear crossbeams, a middle small crossbeam, longitudinal beams, and a grid beam. After installation, it is anchored to the track. The turntable structure of the slewing crane 6 is lifted as a whole by the tower crane 7 and raised to the bridge deck for installation with the crane support frame. During the process, the turntable is rotated to the set position using guy ropes. The tower crane 7 is used to install the turntable hydraulic system, slewing mechanism, electrical system, tripod, etc., into place. After the above structures are installed, the electrical system is debugged to ensure that the slewing mechanism, winch, and traveling mechanism can operate normally. The boom, including the luffing cable, is assembled into a whole near the tower crane 7. The slewing mechanism is started so that the turntable structure makes an angle of about 45° with the center line of the bridge. At the same time, the luffing wire rope is lowered to the bridge deck. A wire rope jig is set up in front of the turntable structure to facilitate the installation of the wire rope. After the tower crane 7 lifts the boom, it is aligned with the turntable structure to complete the installation of the boom pin.

[0088] After the boom pin is installed, without releasing the hook, the luffing wire rope is installed manually. Once the luffing wire rope is installed, the boom is pulled up using a winch. After the boom is pulled up, the hook, hoisting wire rope, etc., are hoisted to the bridge deck using tower crane 7, completing all installation work.

[0089] As a preferred embodiment of the above, after the slewing crane 6 is assembled and before it is moved, a no-load operation test, a static load test, and a slewing rotational load test are performed. In this embodiment, the static load test and the slewing rotational load test can both be performed using existing methods; while the no-load operation test includes:

[0090] Start the lifting mechanism of the slewing crane 6, and lift the hook to run back and forth vertically along the boom several times without load. During the operation, at least judge the phenomenon of wheel slippage and jamming, the starting and braking conditions, and the sensitivity of the switch action.

[0091] In addition, the slewing mechanism of the slewing crane 6 is started, and the crane boom is rotated 360 degrees and the boom is rotated vertically back and forth several times. During the operation, the starting and braking conditions, as well as the sensitivity of the switch action, are judged at least.

[0092] In the construction of hybrid beam cable-stayed bridges, the no-load operation test of the slewing crane 6 is crucial, directly affecting construction safety and efficiency. The test, simulating no-load operation, allows for the early detection of potential faults such as wheel slippage, starting and braking performance issues, and switch sensitivity. This ensures the reliable operation of the slewing crane 6 during subsequent hoisting of heavy steel main beams, bridge decks, and other components, preventing structural damage or engineering accidents due to mechanical failure. Furthermore, conducting this test in a temporary support environment reduces construction delays and ensures a continuous construction process for the steel-concrete composite section.

[0093] As a further optimization, the no-load operation test also includes:

[0094] A1: During the test, the current curves of the lifting mechanism motor and the slewing mechanism motor of the rotary crane 6 are monitored in real time by sensors; thereby capturing the micro fluctuations of the motor load, such as current abnormalities caused by sudden changes in mechanical friction, gear meshing clearance or micro deformation of the temporary support 1.

[0095] A2: Record the current curve under undisturbed conditions, calculate the average steady-state current as the benchmark value, and set a reasonable range for the fluctuation threshold; In this embodiment, undisturbed conditions refer to wind speed ≤3m / s, temperature between 5℃ and 35℃, and the temporary support pier 1 structural condition meeting the requirements; For the acquisition of steady-state current, based on steady-state conditions, the motor is in a constant speed continuous operation phase, for example, the lifting mechanism is raised and lowered at a constant speed of 0.5m / s, and the slewing mechanism is rotated at a constant speed of 0.5r / min. At this time, the motor output torque is balanced with the mechanical resistance, and the current fluctuation tends to be stable. In this steady-state phase, current data of ≥30 seconds is extracted, and the arithmetic mean is taken after removing the start-stop transient values;

[0096] A3: Install an acceleration sensor at a designated node on the temporary support pier 1 on the side span to synchronously collect the vibration frequency during the test.

[0097] A4: When the current fluctuation exceeds the threshold, in this embodiment, it refers to the current fluctuation of either the lifting mechanism motor or the slewing mechanism motor exceeding the set threshold. Specifically, the threshold can be set to 10%. The vibration spectrum at the corresponding moment is extracted. If the dominant vibration frequency in the vibration spectrum overlaps with the natural frequency of the temporary support 1, it is determined that there is a risk of resonance. The vibration spectrum is a full-band energy distribution map, and the dominant vibration frequency is the core characteristic value in the spectrum, which can be obtained through existing technical means. During implementation, when the dominant vibration frequency falls into the measured natural frequency range of the temporary support 1, it indicates that the external excitation frequency is coupled with the natural frequency of the structure, and the vibration energy will continue to amplify, which will form harmful resonance.

[0098] A5: Based on the assessment of resonance risk, the lifting speed of the slewing crane 6 will be adjusted.

[0099] Completing current and vibration monitoring during the no-load testing phase, rather than the actual hoisting phase, allows for the early detection of potential resonance risks. Compared to the traditional approach of passively responding to abnormal vibrations during hoisting, this preferred solution moves the risk management window forward, avoiding project delays caused by mid-hoisting interruptions to the main steel beam. During implementation, the micro-fluctuations of the motor load are captured through current curves, identifying abnormal torque changes caused by micro-deformation of temporary support 1; synchronous vibration spectrum analysis quantitatively locates the resonance frequency; the two work together to achieve dual-dimensional verification of current anomalies and structural responses, significantly reducing the false positive rate and ensuring the safety redundancy of the support system.

[0100] As a further optimization of this embodiment, during the operation of the slewing crane 6, the current curves of the lifting mechanism motor and the slewing mechanism motor of the slewing crane 6 are monitored in real time. When it is determined that there is a risk of resonance, a speed adjustment command is triggered. Specifically, during the first trigger, the hoisting speed is reduced to 80% of the original speed, and during the second trigger, the hoisting speed is further reduced to 50% of the original speed, and an alarm is issued.

[0101] In this preferred scheme, the initial speed reduction balances safety and efficiency, avoiding excessive speed reduction that could delay the construction period. The secondary triggering of strong intervention blocks the path of resonance deterioration. With dynamic and flexible control logic, construction efficiency is maintained to the maximum extent while ensuring the safety of temporary supports.

[0102] In this preferred scheme, the object of hoisting speed adjustment needs to be accurately distinguished according to the source of resonance risk. If the resonance risk is triggered by abnormal motor current of the lifting mechanism, the vertical lifting speed is adjusted. If it is triggered by abnormal motor current of the slewing mechanism, the horizontal rotation speed of the boom is adjusted. If both mechanisms are abnormal at the same time, the vertical and horizontal speeds are reduced simultaneously.

[0103] As a preferred embodiment of the above, such as Figure 8 As shown, the hoisting of steel main beam segment 0 (section 8) is carried out, including:

[0104] B1: Locate and mark the center of the main steel beam on the steel beam support;

[0105] B2: When hoisting the steel main beam section 0 to the set distance from the top surface of the steel beam support, use the center line of the steel main beam to locate the plane position, and lower it at the set speed, requiring the lowering speed to be slow and stable;

[0106] B3: Conduct elevation measurement of the top surface of section 8 of the steel main beam 0, and adjust the steel plate filling on the bottom surface of section 8 of the steel main beam 0 based on the measurement results.

[0107] The entire process can be achieved using the bridge deck slewing crane 6. Through the above steps, precise positioning can be achieved in one hoisting operation. Centerline-based point positioning combined with buffer distance lowering avoids hard collisions between the steel main beam and the support, ensuring the accuracy of the installation plane position. During the lowering process, the top surface elevation is measured simultaneously, and manufacturing errors and support settlement are actively compensated by filling the bottom with steel plates to ensure the elevation deviation of the beam segment. In the implementation process, the repeated lifting and adjustment procedures in traditional hoisting can be eliminated, shortening the construction period and reducing the risks of high-altitude operations.

[0108] As a preferred embodiment of the above, such as Figure 9 As shown, the hoisting of steel crossbeam 10 corresponding to steel main beam segment 8 (section 0) includes:

[0109] C1: Divide the steel beam 10 into three parts along its length and store them at the bottom of the pier;

[0110] C2: The first part of the steel crossbeam 10 on the side away from the tower crane 7 is lifted by the slewing crane 6, and the second and third parts of the steel crossbeam 10 are lifted sequentially by the tower crane 7; each part may be attached with a connecting plate to the steel main beam and the steel crossbeam 10, and the steel main beam lifting process can be referred to for details; in this step, the slewing crane 6 and the tower crane 7 are used in coordination. After the steel crossbeam 10 is set in sections, the lifting capacity of the tower crane 7 meets the requirements. By using it to lift the second and third parts of the steel crossbeam 10 on the side closest to itself, the load on the slewing crane 6 and the risk of high-altitude movement operations can be reduced, and the lifting efficiency can be improved;

[0111] C3: After each part is hoisted, it is aligned and connected with the main steel beam, and the bottom is filled with adjusting steel plates between the distribution beam of the steel beam support.

[0112] Specifically, after the first part is hoisted, it is aligned with the steel main beam segment 0 8 and driven in with punch pins. The bottom of the first part of the steel crossbeam 10 is padded with steel plates and filled tightly between it and the distribution beam. The second and third parts are also subjected to the same process. After each segment is hoisted, it is independently aligned with the steel main beam and the bottom is filled with steel plates. This can eliminate the cumulative error of the segments and ensure the overall alignment deviation of the steel crossbeam 10.

[0113] As a preferred embodiment of the above, the construction method for the steel-concrete composite section of the bridge deck crane based on the forward movement of the temporary support for the side span further includes:

[0114] The longitudinal and transverse prestressing tensioning, grouting, and curing of the bridge deck of steel main beam segments 0 and 1 were carried out; the 9 stay cables of steel main beam segment 1 were subjected to secondary tensioning. Through the above process, the structural internal stress of the steel-concrete joint section was reduced, long-term deformation was precisely controlled, and the adverse effects of concrete shrinkage and creep on the joint section were reduced.

[0115] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for a steel-concrete combined section of a bridge deck crane based on the forward movement of a temporary support across the span, applied in the construction of a hybrid girder cable-stayed bridge, characterized in that, The method comprises the following steps: temporary support piers are erected on both sides of the tower, and hoisting and positioning platforms and crane assembly platforms are erected on the temporary support piers on the main span side and the side span side, and a temporary support for moving the crane is erected between the crane assembly platforms and the hoisting and positioning platforms; the crane is used to hoist and deliver the components of the rotary crane on the bridge deck to the crane assembly platform for installation; after the rotary crane is assembled, the rotary crane is moved to the position corresponding to the hoisting and positioning platform through the temporary support for moving the crane and is anchored and fixed in position; a steel beam support is erected on the temporary support pier on the main span side and is pre-pressed; the 0th section of the steel main beam is hoisted; the corresponding steel cross beam of the 0th section of the steel main beam is hoisted; the concrete of the steel-concrete joint section is poured, maintained and demoulded, and the longitudinal and transverse prestress of the steel-concrete joint section is tensioned and grouted; the small longitudinal beam corresponding to the 0th section of the steel main beam is hoisted; the rotary crane is moved forward to the position corresponding to the 0th section of the steel main beam and is anchored and fixed in position; the 1st section of the steel main beam and the corresponding steel cross beam and small longitudinal beam are hoisted; the stay cables of the 1st section of the steel main beam are hung and installed and are initially tensioned; the bridge deck slabs of the 0th and 1st sections of the steel main beam are hoisted; the cast-in-situ bridge deck slabs and wet joints from the 0th to 1st sections of the steel main beam are poured, maintained and secondarily tensioned.

2. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, After the rotary crane is anchored and fixed in position, the crane assembly platform and the temporary support for moving the crane are removed.

3. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, The bottom of the rotary crane comprises a crane support support, the crane support support comprises front and rear end cross beams arranged in parallel, the hoisting and positioning platform comprises a support pier cross beam connected to the temporary support pier, and the front end cross beam is moved to the top of the support pier cross beam and is positioned.

4. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, After the rotary crane is assembled, the rotary crane is moved, and an empty load running test, a static load test and a rotary dynamic load test are performed.

5. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 4, characterized in that, The empty load running test comprises: the lifting mechanism of the rotary crane is started, the hook is lifted and runs vertically along the lifting arm several times in an empty load state, and at least the following are judged during the running: the slipping and jamming of the rotating wheel, the starting and braking conditions and the sensitivity of the opening and closing actions; the rotating mechanism of the rotary crane is started, the rotary crane is rotated by 360 degrees and the lifting arm is vertically rotated several times, and at least the following are judged during the running: the starting and braking conditions and the sensitivity of the opening and closing actions.

6. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 5, characterized in that, The empty load running test further comprises: during the test, the current curves of the motor of the lifting mechanism and the motor of the rotating mechanism of the rotary crane are monitored in real time by sensors; the current curves in the non-interference state are recorded, the average value of the steady-state current is calculated as a reference value, and a reasonable interval of the fluctuation threshold is set; an acceleration sensor is installed at a node of the temporary support pier on the side span side, and the vibration frequency during the test is synchronously collected; when the current fluctuation exceeds the threshold, the vibration spectrum at the corresponding time is extracted, if the vibration main frequency in the vibration spectrum overlaps with the natural frequency of the temporary support pier, it is determined that there is a risk of resonance; the hoisting speed of the rotary crane is adjusted according to the judgment of the risk of resonance.

7. The construction method of the steel-concrete combined section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 6, characterized in that, In the working process of the slewing crane, the current curve of the lifting mechanism motor and the slewing mechanism motor of the slewing crane is monitored in real time, and when it is judged that the resonance risk occurs, the trigger speed regulation instruction is started; wherein, when triggered for the first time, the lifting speed is reduced to 80% of the original speed, and when triggered for the second time, the lifting speed is further reduced to 50% of the original speed, and an alarm is issued.

8. The construction method of the steel-concrete joint section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, The steel girder 0 section is hoisted, including: The center of the steel girder 0 section is positioned and laid on the steel beam support; When the distance between the steel girder 0 section and the top surface of the steel beam support is a set value, the center line of the steel girder 0 section is used to position and locate the plane position, and the steel girder 0 section is lowered at a set speed. The top elevation of the steel girder 0 section is measured, and the steel plate is adjusted according to the measurement results on the bottom surface of the steel girder 0 section.

9. The construction method of the steel-concrete joint section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, The corresponding steel cross beam of the steel girder 0 section is hoisted, including: The steel cross beam is divided into three parts along the length direction and stored at the bottom of the pier; The first part of the steel cross beam away from the side where the tower crane is located is hoisted by the slewing crane, and the second part and the third part of the steel cross beam are hoisted by the tower crane in turn; After each part is hoisted, the alignment connection with the steel girder is performed, and the steel plate is adjusted between the bottom and the distribution beam of the steel beam support.

10. The construction method of the steel-concrete joint section of the bridge deck crane based on the forward movement of the temporary support of the side span according to claim 1, characterized in that, Further including: The longitudinal and transverse prestress tensioning, grouting and maintenance of the deck slab of the steel girder 0 section and the steel girder 1 section are performed; The stay cable of the steel girder 1 section is tensioned twice.

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