Method for installing continuous jack deck crane of large-span double-tower double-cable-plane cable-stayed bridge

Abstract

The invention provides a large-span double-tower double-cable-plane cable-stayed bridge continuous jack bridge floor crane installation method, and belongs to the technical field of cable-stayed bridge installation, and the method comprises the following steps: installing a front fulcrum on a bridge floor, installing a front distribution beam on a front fulcrum structure and fixing the front distribution beam, installing a rear walking mechanism, installing a bottom beam on the front fulcrum structure and the rear walking mechanism and fixing the bottom beam, mounting a rear anchoring beam at a rear walking position; mounting a stand column and an upper rotating hinge on a front supporting structure; mounting a counter weight and a pump station at the rear walking position; mounting a straining beam in place through a pin shaft, mounting an inner triangular horizontal supporting rod on an inclined strut, arranging and mounting the supporting rods on a bottom beam, and connecting an inner triangular vertical supporting rod, the inclined supporting rod and a main beam; and the whole body is installed on the inclined strut, the jack is adjusted for connection and fixation, and the hanger is installed. Each part of the bridge deck crane is hoisted to the bridge deck to be installed, the bridge deck crane is installed according to the actual situation of the bridge deck, position debugging and testing are conducted after each part is installed, and the installation precision of the whole bridge deck crane is controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of cable-stayed bridge installation, and particularly to a method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge. Background Art

[0002] With the continuous development of transportation infrastructure construction, the construction demand for long-span cable-stayed bridges is increasing day by day. Long-span double-tower double-cable-plane cable-stayed bridges have problems such as great difficulty in segmental prefabrication and installation, great difficulty in controlling welding deformation, and high precision in cable force adjustment and alignment control. To explore the steel box girder construction technology of long-span cable-stayed bridges in the case where navigation is restricted and large river floating cranes cannot enter the site.

[0003] Chinese Patent with publication number CN 112695643 A discloses a bridge deck crane and its lifting platform. This bridge deck crane mainly assembles the scattered prefabricated members in advance by a 50t truck crane and then hoists them as a whole to the bridge deck, which is likely to cause installation errors and is difficult to accurately dock during later hoisting. Therefore, it is necessary to design a method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge, and solve the technical problems of great difficulty in segmental prefabrication and installation, great difficulty in controlling welding deformation, and high precision in cable force adjustment and alignment control of existing long-span cable-stayed bridges.

[0005] By applying the continuous jack bridge deck crane, the disadvantages of conventional floating crane hoisting and self-made gantry beam hoisting processes are effectively overcome, and it has the characteristics of high efficiency in beam hoisting construction, high precision in positioning and closing, and safety and reliability during the construction process.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge, the method comprising the following steps:

[0008] Step 1: Install a front support on the bridge deck and accurately position it;

[0009] Step 2: Install and fix a front distribution beam on the front support structure;

[0010] Step 3: Install a rear traveling mechanism at the corresponding position on the bridge deck;

[0011] Step 4: Install and fix a bottom beam on the front support structure and the rear traveling mechanism;

[0012] Step 5: Install a rear anchor beam at the rear traveling position, and install a column and an upper rotating hinge on the front support structure;

[0013] Step 6: Install the counterweight and the pump station at the rear walking position, and install the draw beam in place with a pin shaft;

[0014] Step 7: Install the inner triangular horizontal strut on the diagonal strut, and then install the strut on the bottom beam after tidying up;

[0015] Step 8: Connect the inner triangular vertical strut, the diagonal strut and the main beam, and install them as a whole on the diagonal strut;

[0016] Step 9: After the auxiliary facilities of the guardrail are installed, assemble the adjustment assembly, hoist it as a whole to the working position of the main beam on the bridge deck crane and connect and fix it with the support adjustment jack;

[0017] Step 10: Install the transverse tie rod between the two bridge deck cranes;

[0018] Step 11: Cut the steel strands according to the usage requirements, pass the steel strands down respectively from the upper part of the lifting jacks, connect the steel strands with the lifting appliances, and use the lifting jacks to lift or lower the lifting appliances to complete the installation.

[0019] Further, in Step 1, first determine the positions to be lifted on both sides of the steel box girder according to the width of the steel box girder, then the front fulcrum and the position to be lifted are on the same straight line, determine the front fulcrum, install the walking system on the front fulcrum, and set three positioning installation points on the steel box girder at the forefront. Light-emitting heads are provided at all three positioning installation points. At the same time, light-receiving plates are installed at the same corresponding positions on the same side of the other steel box girder to be installed. When installing the steel box girder, when the lights of the three light-emitting heads are respectively on the three light-receiving plates, it means that both horizontal and vertical alignments are achieved.

[0020] Further, the three positioning light-emitting heads are not on the same horizontal line nor on the same vertical line. The positioning light-emitting heads are arranged on the sides of the bolt holes, and three-point positioning is used to complete the three-dimensional space positioning.

[0021] Further, in Step 11, a speed sensor is installed on the lifting appliance. The speed sensor is used to detect the speed of the lifting appliance during the rising process in real time. At the same time, an offset detection laser probe is also provided on the lifting appliance, and the offset detection laser probe emits vertically upward.

[0022] Further, in step 8, a rectangular laser receiving plate is provided at the lower end of the main beam. The rectangular laser receiving plate is provided with a number of regularly arranged receiving probes. Initially, the offset detection laser probe is adjusted to be aligned with the middle position of the rectangular laser receiving plate, and the three-dimensional receiving probe being aligned indicates verticality, and the spreader has no offset. During hoisting, if the offset detection laser probe shines on the receiving probe inside the rectangular laser receiving plate, it indicates that the spreader has an inward offset. If the receiving probe that the offset detection laser probe shines on is not a fixed point, it means that the spreader is shaking. Adjustment measures should be taken in a timely manner according to the hoisting offset and shaking errors to avoid accidents.

[0023] Further, the above solution also includes the work preparation before trial hoisting. The specific process is as follows:

[0024] Positioning of the bridge deck crane: Determine the hoisting working position according to the hoisting design requirements of the trial hoisted box girder. After positioning, install the rear anchor system and the front support structure before hoisting work can be carried out;

[0025] Obtain the conventional weather forecast within 24 hours before hoisting to ensure that the weather conditions are within the required range for hoisting. Combine the weather conditions to observe environmental changes to ensure that the wind and wave conditions meet the requirements;

[0026] Ensure the safety of box girder hoisting: Fix any equipment and components, install safety guardrails all around. For any additional weight of the beam segment, equipment and components, it must be checked and confirmed that their distribution is uniform and within the safe hoisting capacity of the bridge deck crane;

[0027] Ensure that all equipment is in good operation before hoisting. Check the hydraulic and electrical operation control systems of all jacks and pumping stations to be used;

[0028] Lower the spreader: Lower it using the lifting jack. When lowering, set the expected load in the computer system according to the weight of the spreader. It can be lowered manually or automatically controlled by the computer program;

[0029] Maintain the wedge grips and adjust the steel strands: Maintain the wedge grips of the lifting jack according to the wedge grip maintenance requirements. Check the wedge grips, bolts, connecting plates, pins and locking plates to ensure safety and reliability during the beam hoisting process. The lifting jack tightens the steel strands. If loose steel strands are found, use a special fixture for adjusting the steel strands to make adjustments. When adjusting the steel strands, transfer the load to the bottom wedge grips and open the top wedge grips. Manual adjustment using a single-hole anchor or point-by-point fine adjustment using a computer is completed, and it is prohibited for the force on a single steel strand to be greater than the set value.

[0030] Further, the above solution also includes the crane test. The specific process is as follows:

[0031] (1) No-load test: After the bridge deck crane reaches the specified position, lock the rear anchor system of the bridge deck crane as required. Turn on the lifting equipment on one side of the bridge deck crane, evenly lower the spreader to the longest position, observe whether the limit switches, hydraulic control system, and the arrangement of the steel strands are normal. Then evenly lift the spreader and also observe whether the height limit switch and the arrangement of the steel strands are normal. Similarly, complete the inspection of the lifting equipment on the other side. After the operation tests of the two sides of the lifting equipment are qualified, conduct a linkage test. Mark the lifting steel strands at equal intervals of 1.0 m. Then turn on the lifting equipment on both sides simultaneously and evenly lower the spreader. Record the synchronization time and deviation value every 1.0 m. Similarly, complete the data collection during lifting.

[0032] (2) Load test: The trial lift of the bridge deck crane is loaded in grades according to 20%, 40%, 60%, 70%, 80%, 90%, 100%, and 125% of the designed rated lifting weight, with the load slightly leaving the ground.

[0033] After positioning the standard beam segment and connecting it to the spreader, check the connection of each component of the bridge deck crane. After confirming that there is no error, drive the hydraulic lifting system of the bridge deck crane to vertically lift the steel box girder.

[0034] Preloading: During loading, gradually transfer the weight of the steel box girder to the lifting jacks. At the initial loading, first adjust the force of each main jack to make them basically the same. When 40% of the load is transferred to the forward lifting jacks, check the jacks, anchoring system, and the connection between the spreader and the steel box girder counterweight again. When the load reaches 90% of the designed load, lift the steel box girder off the barge with an empty stroke once to reduce the swaying of the steel box girder after leaving the barge. The operator observes the force conditions at each point and adjusts the force at each point according to the theoretical lifting point force conditions of the beam segment to ensure that the beam segment is lifted horizontally during hoisting. At the same time, the center of gravity adjustment jack on the spreader can also be used to adjust the center of gravity of the beam segment.

[0035] Use the force measuring device of the lifting mechanism to calculate the load borne by the lifting points of the bridge deck crane. When the single-point load increases by one level, check each component of the bridge deck crane and make records.

[0036] After the entire steel box girder is borne by the bridge deck crane, check again and make records. The height of the steel box girder leaving the barge support is controlled within 10 cm. The steel box girder is separated from the support and stabilized for 60 minutes. After checking that everything is normal, lower the steel box girder, and the overload test of the bridge deck crane ends.

[0037] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0038] In the present invention, each component of the bridge deck crane is lifted onto the bridge deck for installation. The bridge deck crane is installed according to the actual situation of the bridge deck. At the same time, after each component is installed, position debugging and testing are carried out, effectively controlling the installation accuracy of the overall bridge deck crane. Meanwhile, three positioning installation points are installed to make the installation of the steel box girder more efficient and accurate in the later stage. A laser probe is installed on the lifting tool, and a laser receiving plate is installed at the lower end of the main beam. The swaying angle during hoisting is judged according to the pointing point of the laser probe, and timely adjustment is made to avoid hoisting accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of the front support point and the corresponding traveling system of the present invention before installation;

[0040] Figure 2 is a schematic structural diagram of the front distribution beam of the present invention before installation;

[0041] Figure 3 is a schematic structural diagram of the traveling mechanism of the present invention after installation;

[0042] Figure 4 is a schematic structural diagram of the bottom beam of the present invention after installation;

[0043] Figure 5 is a schematic structural diagram of the anchor beam of the present invention after installation;

[0044] Figure 6 is a schematic structural diagram of the counterweight and the pump station of the present invention during assembly;

[0045] Figure 7 is a schematic structural diagram of the installation of the inner triangular horizontal strut of the present invention;

[0046] Figure 8 is a schematic structural diagram of the connection between the diagonal strut and the main beam of the present invention;

[0047] Figure 9 is a schematic structural diagram of the connection and fixation of the jack of the present invention;

[0048] Figure 10 is a schematic structural diagram of the installation of the transverse tie rod of the present invention;

[0049] Figure 11 is a schematic structural diagram of the installation of the lifting tool of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention clearer and more understandable, the following preferred embodiments are given with reference to the accompanying drawings, and the present invention is further described in detail. However, it should be noted that many details listed in the specification are only for the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be realized even without these specific details.

[0051] AsFigures 1-11 As shown in Figures 1-11 , a method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge, the method comprising the following steps:

[0052] Step 1: Install the front support on the bridge deck and accurately position it. First, determine the positions on both sides of the steel box girder that need to be lifted according to the width of the steel box girder. Then, ensure that the front support and the positions to be lifted are on the same straight line. After determining the front support, install the traveling system on the front support, and set three positioning installation points on the steel box girder at the forefront. Each of the three positioning installation points is provided with a light-emitting head. At the same time, install a light-receiving plate at the same corresponding position on the same side of another steel box girder to be installed. When installing the steel box girder, when the lights of the three light-emitting heads are respectively on the three light-receiving plates, it means that both horizontal and vertical alignments are achieved. The three positioning light-emitting heads are not on the same horizontal line nor on the same vertical line. The positioning light-emitting heads are arranged on the side of the bolt hole, and three-point positioning is used to complete the three-dimensional space positioning.

[0053] Step 2: Install and fix the front distribution beam on the front support structure. Install lifting rings (diameter ≥ Φ150mm) at both ends of the distribution beam, and use the four-point lifting method to maintain balance, and monitor the level in real time (error ≤ 2‰L). Use high-strength bolts (pre-tightening force 30% - 50%) to temporarily connect the distribution beam and the support structure, with at least 4 groups of bolts at each end. Fine-tune through a jack (stroke ±50mm) in combination with a laser level to ensure that the longitudinal slope of the distribution beam ≤ 1 / 300. Use CO2 gas shielded welding to fully weld the key joints (such as near the support), and the weld height ≥ 6mm. Tighten to the design torque (such as 120kN·m for M16 bolts) in 3 - 4 times in the diagonal order, and the torque detection qualification rate is 100%.

[0054] Step 3: Install the rear traveling mechanism at the corresponding position on the bridge deck. The strength of the bridge deck concrete ≥ C40, and the flatness ≤ 3mm / 3m (detected by a laser level). Lay a ballast or steel plate leveling layer, and the compactness ≥ 95%. Use a track gauge (error ≤ ±2mm) to lay section by section, and the deviation of the adjacent sleeper spacing is ±5mm. Use fishplates to weld the track joints, and the weld height ≥ 6mm, and grind it flat. The concentricity deviation between the driving wheel and the driving shaft ≤ 0.1mm, and the driven wheel is connected to the frame through a pin shaft. The installation angle error of the guide wheel ≤ 1°, and ensure that the lateral clearance with the track is consistent (usually 3 - 5mm). At the same time, a brake is installed, the surface roughness Ra of the brake disc ≤ 1.6μm, and the installation torque (such as 200N·m for M12 bolts). Conduct a power-on braking test: after power-off, the response time of the brake ≤ 0.3s, and the braking distance meets the design requirements.

[0055] Step 4: Install and fix the bottom beam on the front support structure and the rear traveling mechanism.

[0056] Step 5: Install the rear anchor beam at the rear traveling position, and install the column and the upper swivel on the front support structure.

[0057] Step 6: Install the counterweight and the pumping station at the rear walking position, and install the pulling beam in place with a pin shaft.

[0058] Step 7: Install the inner triangular horizontal strut on the diagonal brace, and then install the brace on the bottom beam after tidying up.

[0059] Step 8: Connect the inner triangular vertical strut, the diagonal strut and the main beam, and install them as a whole on the diagonal brace. A rectangular laser receiving plate is provided at the lower end of the main beam. The rectangular laser receiving plate is provided with a number of regularly arranged receiving probes. Initially, adjust the offset detection laser probe to align with the middle position of the rectangular laser receiving plate. When the three-dimensional receiving probe is aligned, it indicates verticality and the spreader has no offset. During hoisting, if the offset detection laser probe shines on the receiving probe inside the rectangular laser receiving plate, it indicates that the spreader has an inward offset. If the receiving probe that the offset detection laser probe shines on is not a fixed point, it means that the spreader is shaking. Make timely adjustment measures according to the hoisting offset and shaking errors to avoid accidents.

[0060] Step 9: After the auxiliary facilities of the guardrail are installed, assemble the adjustment assembly, hoist it as a whole to the working position of the main beam on the bridge deck crane and connect and fix it with the support adjustment jack.

[0061] Step 10: Install the transverse tie rod between the two bridge deck cranes.

[0062] Step 11: Cut the steel strands according to the usage requirements, pass the steel strands down respectively from the upper part of the lifting jacks, connect the steel strands with the spreader, and use the lifting jacks to lift or lower the spreader to complete the installation. A speed sensor is installed on the spreader. The speed sensor is used to detect the speed of the spreader during the rising process in real time. At the same time, an offset detection laser probe is also provided on the spreader, and the offset detection laser probe emits vertically upward.

[0063] The above method also includes the work preparation before the trial hoisting. The specific process is as follows:

[0064] Positioning of the bridge deck crane: Determine the hoisting working position according to the hoisting design requirements of the trial hoisted box girder. After positioning, install the rear anchor system and the front support structure before the hoisting work can be carried out;

[0065] Obtain the regular weather forecast within 24 hours before hoisting, ensure that the weather conditions are within the requirements for hoisting, and observe the environmental changes in combination with the weather conditions to ensure that the wind and wave conditions meet the requirements;

[0066] Ensure the safety of box girder hoisting: Fix any equipment and components, install safety guardrails all around, and check and confirm that any additional weight, equipment and components of the beam section are evenly distributed and within the safe hoisting capacity of the bridge deck crane;

[0067] Ensure that all equipment is in good working condition before hoisting. Check the control systems for the hydraulic and electrical operations of all jacks and pump stations to be used.

[0068] Lower the lifting tackle: Use the lifting jack to lower it. When lowering, set the expected load in the computer system according to the weight of the lifting tackle. The lifting tackle can be lowered manually or automatically controlled by the computer program.

[0069] Maintain the wedge grips and adjust the steel strands: Maintain the wedge grips of the lifting jack according to the maintenance requirements of the wedge grips. Check the wedge grips, bolts, connecting plates, pins, and lock plates to ensure safety and reliability during the lifting of the beam. The lifting jack tightens the steel strands. If loose steel strands are found, use a special fixture for adjusting the steel strands to adjust them. When adjusting the steel strands, transfer the load to the bottom wedge grips and open the top wedge grips. Manually adjust with a single-hole anchor or use the computer to complete the jogging adjustment. Ensure that the force on a single steel strand does not exceed the set value.

[0070] The above method also includes a crane test. The specific process is as follows:

[0071] (1) No-load test: After the bridge crane reaches the designated position, lock the rear anchor system of the bridge crane as required. Turn on the lifting equipment on one side of the bridge crane and evenly lower the lifting tackle to the longest position. Observe whether the various limiters, the hydraulic control system, and the arrangement of the steel strands are normal. Evenly lift the lifting tackle and also observe whether the height limiter and the arrangement of the steel strands are normal. Similarly, complete the inspection of the lifting equipment on the other side. After the operation tests of the lifting equipment on both sides are qualified, conduct a linkage test. Make marks on the lifting steel strands at equal intervals of 1.0 m. Turn on the lifting equipment on both sides at the same time and evenly lower the lifting tackle. Record the synchronization time and deviation value every 1.0 m. Similarly, complete the data collection during lifting.

[0072] (2) Load test: The trial hoisting of the bridge crane is loaded in grades according to 20%, 40%, 60%, 70%, 80%, 90%, 100%, and 125% of the designed rated lifting weight, with the load slightly leaving the ground.

[0073] After positioning the standard beam segment and connecting it to the lifting tackle, check the connection conditions of all components of the bridge crane. After confirming that there is no error, drive the hydraulic lifting system of the bridge crane to vertically lift the steel box girder.

[0074] Preloading: Gradually transfer the weight of the steel box girder to the lifting jacks during loading. At the initial loading stage, first adjust the force on each main jack to make them basically the same. When 40% of the load is transferred to the forward lifting jacks, check the jacks, anchoring system, and the connection between the sling and the counterweight of the steel box girder again. When the loading reaches 90% of the load, lift the steel box girder off the barge with an empty stroke once to reduce the swaying of the steel box girder (after leaving the barge). The operator observes the force conditions at each point and adjusts the force at each point according to the force conditions at the theoretical lifting points of the beam segment to ensure that the beam segment is lifted horizontally during the hoisting process. At the same time, the center-of-gravity adjusting jack on the sling can also be used to adjust the center of gravity of the beam segment;

[0075] The force measuring device of the lifting mechanism is used to calculate the load borne by the lifting points of the bridge crane. When the single-point load increases by one level, check each component of the bridge crane and make records;

[0076] After the entire steel box girder is borne by the bridge crane, check again and make records. The height of the steel box girder from the barge support is controlled within 10 cm. The steel box girder is disengaged from the support and stabilized for 60 minutes. After checking that everything is normal, lower the steel box girder, and the overload test of the bridge crane ends.

[0077] Matters not covered by this invention are well-known technologies.

[0078] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge, which is characterized by: The method comprises the following steps: Step 1: Install the front support on the bridge deck and position it accurately; Step 2: Install the front distribution beam on the front support structure and fix it; Step 3: Install the rear traveling mechanism at the corresponding position on the bridge surface; Step 4: Install and secure the bottom beam on the front support structure and the rear walking mechanism; Step 5: Install the rear anchor beam at the rear walking position, and install the column and upper turntable on the front support structure; Step 6: Install the counterweight and pump station at the rear travel position, and install the tension beam in place with the pin; Step 7: Install the inner triangular horizontal brace onto the diagonal brace, and then install the brace onto the bottom beam; Step 8: Connect the inner triangular vertical brace, diagonal brace and main beam, and install the whole on the diagonal brace; Step 9: After the auxiliary facilities of the guardrail are installed, assemble the adjustment assembly, hoist it as a whole to the working position of the main beam on the bridge crane, and connect and fix it with the bracket adjustment jack; Step 10: Install the horizontal tie rod between the two bridge cranes; Step 11: Lay out the steel strands according to the needs, pass them through the upper part of the lifting jack, connect the steel strands with the sling, use the lifting jack to lift or lower the sling to complete the installation.

2. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 1 is characterized in that: In step 1, first determine the positions on both sides of the steel box girder that need to be lifted according to the width of the steel box girder, then the front fulcrum and the position that needs to be lifted are in the same straight line, determine the front fulcrum, install the walking system on the front fulcrum, and set three positioning installation points on the front end of the steel box girder. The three positioning installation points are all equipped with light heads. At the same time, a light receiving board is installed at the same corresponding position on the same side of another steel box girder with installation. When installing the steel box girder, when the light from the three light heads is on the three light receiving boards respectively, it means that both horizontal and vertical alignment are achieved.

3. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 1, characterized in that: The three positioning light heads are not on the same horizontal line, nor on the same vertical line. The positioning light heads are arranged on the sides of the bolt holes, and three-dimensional spatial positioning is completed through three-point positioning.

4. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 1, characterized in that: In step 11, a speed sensor is installed on the spreader, and the speed sensor is used to detect the speed of the spreader during the rising process in real time. At the same time, an offset detection laser probe is also provided on the spreader, and the offset detection laser probe is vertically upward.

5. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 4 is characterized in that: In step 8, a rectangular laser receiving plate is provided at the lower end of the main beam, and a number of regularly arranged receiving probes are provided on the rectangular laser receiving plate. Initially, the offset detection laser probe is debugged and aligned with the middle position of the rectangular laser receiving plate. The three-dimensional receiving probe is aligned to indicate verticality, and the hoist has not shifted. During hoisting, if the offset detection laser probe is directed to the receiving probe on the inner side of the rectangular laser receiving plate, it indicates that the hoist has shifted inward. If the receiving probe directed to by the offset detection laser probe is not a fixed point, it indicates that the hoist is shaking. Adjustment measures should be made in time according to the offset and shaking errors of the hoisting to avoid accidents.

6. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 1, characterized in that: It also includes the work preparation before trial lifting, the specific process is: Bridge crane parking position: Determine the hoisting work position according to the design requirements of the trial box girder hoisting. After positioning, install the rear anchor system and the front support structure before the hoisting work can be carried out; Obtain regular weather forecast within 24 hours before lifting to ensure that the weather conditions are within the lifting requirements, and observe environmental changes in combination with weather conditions to ensure that wind and wave conditions meet the requirements; Ensure the safety of box girder hoisting: all equipment and components must be fixed, safety guardrails must be installed around, and any additional weight of the beam section, equipment and components must be checked to confirm that they are evenly distributed and within the safe hoisting capacity of the bridge crane; Before lifting, make sure all equipment is in good working order and check the hydraulic and electrical control systems of all jacks and pump stations to be used; Lowering the spreader: Use a lifting jack to lower it. When lowering it, the wire is collected and the expected load is set in the computer system according to the weight of the spreader. The spreader can be lowered manually or automatically controlled by a computer program. Maintain clips and adjust steel strands: Maintain the lifting jack clips according to the clip maintenance requirements, check the clips, bolts, connecting plates, pins and locking plates to ensure safety and reliability during the beam lifting process, tighten the steel strands with the lifting jack, and if loose steel strands are found, adjust them with a special clamp for adjusting the steel strands. When adjusting the steel strands, the load is transferred to the bottom clip and the top clip is opened. Manual adjustment with a single-hole anchor or inching fine-tuning with a computer is used to prevent a single steel strand from being subjected to a force greater than the set value.

7. The method for installing a continuous jack bridge deck crane for a long-span double-tower double-cable-plane cable-stayed bridge according to claim 1, characterized in that: It also includes crane test, the specific process is as follows: (1) No-load test: When the bridge crane reaches the designated position, tighten the rear anchor system of the bridge crane as required, start the lifting equipment on one side of the bridge crane, evenly lower the sling to the longest position, observe whether the limit and hydraulic control system, and the arrangement of the steel strands are normal, evenly lift the sling, and also observe whether the height limit and the arrangement of the steel strands are normal. Similarly, complete the inspection of the lifting equipment on the other side. After the operation test of the lifting equipment on both sides is passed, conduct a linkage test. Mark the lifting steel strands at an equal distance of 1.0m at the time of wire collection. At the same time, start the lifting equipment on both sides, evenly lower the sling, and record the synchronization time and deviation value every 1.0m. Similarly, complete the data collection during lifting. (2) Load test: The test load of the bridge crane shall be graded according to the design rated lifting weight in the following levels: 20%, 40%, 60%, 70%, 80%, 90%, 100% and 125%, with the load slightly off the ground. After positioning the standard beam section, connect it to the hoisting device, check the connection of each component of the bridge crane, and after confirming that it is correct, drive the hydraulic lifting system of the bridge crane to vertically lift the steel box beam; Preloading: During loading, the weight of the steel box girder is gradually transferred to the lifting jack. During the initial loading, the force of each main jack is adjusted to keep them basically the same. When 40% of the load is transferred to the lifting front, the connection between the jack, anchoring system and the sling and the counterweight of the steel box girder is checked again. When the load reaches 90%, an empty stroke is used to lift the steel box girder away from the barge to reduce the shaking of the steel box girder (after leaving the barge). The operator observes the force conditions of each point and adjusts the force of each point according to the force conditions of the theoretical lifting points of the beam section to ensure that the beam section is lifted horizontally during the lifting process. At the same time, the center of gravity adjustment jack on the sling can also be used to adjust the center of gravity of the beam section. The force measuring device of the lifting mechanism is used to calculate the load borne by the lifting point of the bridge crane. When the single-point load increases by one level, each component of the bridge crane is inspected and recorded; After the steel box girder is fully carried by the bridge crane, check again and make records. The height of the steel box girder away from the barge support is controlled within 10cm. The steel box girder is detached from the support and stabilized for 60 minutes. After checking that everything is normal, lower the steel box girder and the bridge crane overload test is completed.

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