A construction method for a cable crane with an asymmetric and unequal height structure

Abstract

The present invention belongs to the field of cable cranes, and specifically relates to a construction method for a cable crane with an asymmetric unequal height structure. The cable crane adopts a gravity anchoring + asymmetric unequal height double-tower solution, wherein the two towers are a cable tower and a main tower, and the height of the cable tower is lower than that of the main tower. Both ends of the load-bearing cable of the cable crane are anchored on the anchors on both sides, and the cable tower is arranged on the anchor on the north bank, and a wind cable is installed through the top of the cable tower at the same time. The main cable and the wind cable are installed alternately to control the unbalanced horizontal force on the top of the cable tower. The present invention makes full use of existing permanent existing structures such as existing anchors and main towers, which can not only reduce the engineering material cost and engineering volume required for the construction of the cable crane, but also is environmentally friendly and has little impact on the terrain. At the same time, the structural strength of the cable tower itself and the alternating installation of the main cable and the wind cable are used to control the unbalanced horizontal force on the top of the cable tower to meet the requirements of safe lifting.

Description

Technical Field

[0001] The invention belongs to the technical field of cable cranes, and in particular relates to a construction method for a cable crane with an asymmetric unequal height structure. Background Art

[0002] The cable hoisting system is a kind of high-altitude lifting equipment that is used to hang cables between two supporting points as weighing tracks for overhead cranes, thus spanning rivers and valleys. It is often used in bridge construction. Currently, the most common cable cranes include double-tower symmetrical cable cranes, towerless cable cranes, and single-tower asymmetrical cable cranes.

[0003] A suspension bridge is a type of bridge. Figure 1 As shown in the figure, the revolving cable suspension bridge in a certain project is a single-tower ground-anchored revolving cable suspension bridge, and the riverbanks on both sides are uneven and are mountain structures, which makes it inconvenient to build large anchors. Therefore, the conventional double-tower symmetrical cable crane system is not suitable. In addition, both the south and north banks are mountain structures, but the heights are lower than the main tower, so towerless cable cranes are not suitable; and the terrain on both sides is complex, which is not convenient for the transportation and construction of installation materials. Building cable towers on the mountains on both sides is labor-intensive and time-consuming, and the construction component is relatively high.

[0004] Therefore, it is necessary to provide a construction method for a cable crane of a single-tower ground-anchored revolving cable suspension bridge applicable to the above-mentioned situation. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a construction method for an asymmetric unequal height structure cable crane.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A construction method for an asymmetric unequal height structure cable crane comprises the following steps:

[0008] Step 1: Construction of cable crane anchoring structure and embedded parts; During the construction of north bank anchoring and south bank anchoring, embedded cable crane related embedded parts are embedded, including main cable anchor embedded parts, wind cable anchor embedded parts, lifting cable anchor embedded parts, traction cable steering embedded parts and cable tower anchor embedded parts; the main tower is set on the south bank side;

[0009] Step 2: Assemble the cable tower on the north bank; Assemble the cable tower using the lifting equipment on the north bank;

[0010] Step 3: Install temporary cable saddle and temporarily shelve the overhead crane; use the main tower crane to hoist the temporary cable saddle, and install the diverting pulleys of the traction rope and the lifting rope on the upper beam of the main tower; install the overhead crane shelving platform on the side of the upper beam of the main tower facing the north bank, lift the overhead crane, and temporarily fix the overhead crane on the shelving platform;

[0011] Step 4: Installation of temporary traction system: Install temporary traction winch and bridge deck horizontal steering wheel on the south bank, and install north bank anchor horizontal steering wheel on the north bank anchor; then manually install the traction system wire rope installed on the outside of the catwalk gantry during the catwalk erection stage into the north bank anchor horizontal steering wheel, bridge deck horizontal steering wheel, and temporary traction winch to form a large-circulation traction system;

[0012] Step 5: Main cable installation and wind cable installation; Main cables and wind cables are installed alternately to control the unbalanced horizontal force on the top of the cable tower; After each main cable is installed, it is adjusted so that the main cable sag reaches the designed empty cable sag, completing the initial adjustment;

[0013] Step 6: Install the traction rope and lifting rope;

[0014] Step 7: Fine-tune the main rope and conduct trial lifting.

[0015] Furthermore, in step five, there are 11 main cables on one side and 4 wind cables. The construction process of alternating installation of the main cables and wind cables is: install 2×5 main cables → install 2×1 bundle of wind cables → install 2×6 main cables → install 2×1 bundle of wind cables; use CNC jacks for tensioning, and the tensioning force value can be digitally displayed.

[0016] Furthermore, in step 5, the alternating installation of the main cable and the wind cable includes the following steps:

[0017] (1) Installation of 1-5# main cables: Install 1-5# main cables simultaneously upstream and downstream, and preliminarily adjust the main cable force and sag. Without considering the wind load, after all 1-5# main cables are tensioned in place, the top of the cable tower is longitudinally deformed by 17mm toward the mid-span side.

[0018] (2) Installation and tensioning of 1# and 4# wind cables: Install the wind cable tower top anchor device on the top of the cable tower. Four wind cable tower top anchor devices are set up corresponding to the four wind cables, namely 1#-4# wind cable tower top anchor devices. The wind cable tower top anchor devices are set up on both sides of the temporary saddle respectively. Install and tension 1# and 4# wind cables synchronously upstream and downstream. Each bundle uses 7-φ15.2 steel strands. The initial tension of a single bundle is 28.98t. After the two wind cables are tensioned in place, the top of the cable tower is longitudinally deformed by 16mm towards the side span.

[0019] (3) Installation of 6-11# main cables: Install and tension 6-11# main cables simultaneously upstream and downstream, and fine-tune the force and sag of 1-11# main cables; after all main cables are tensioned in place, the top of the cable tower will be longitudinally deformed by 2mm toward the mid-span side;

[0020] (4) Installation and tensioning of 2# and 3# wind cables: 2# and 3# wind cables are installed and tensioned synchronously and symmetrically upstream and downstream. After the two wind cables are tensioned into place, the top of the cable tower is longitudinally deformed by 24 mm towards the side span.

[0021] Furthermore, the size of the north bank anchor is smaller than that of the south bank anchor, and the north bank anchor has the following embedded parts: ① cable tower anchor embedded parts; ② main cable anchor embedded parts; ③ traction cable steering embedded parts; ④ lifting cable anchor embedded parts; ⑤ wind cable anchor embedded parts; the south bank anchor has the following embedded parts: ① main cable anchor embedded parts; ② traction cable steering embedded parts; the south bank anchor is also equipped with a main cable adjustment system and a cable laying site.

[0022] Furthermore, the north bank anchor is a surface-covered gravity anchor, and the bottom surface of the north bank anchor is designed as a concave and convex stepped tooth block; the cable tower anchor embedded parts are arranged on the south side of the north bank anchor, 2-2.5m away from the south edge of the north bank anchor; in the north bank anchor, the main cable anchor embedded parts, the towing and protection cable steering embedded parts, the lifting cable anchor embedded parts, and the wind cable anchor embedded parts are buried on the north side of the north bank anchor, 4-8m away from the north edge of the north bank anchor; the distance from the cable tower anchor embedded parts to the wind cable anchor embedded parts is 48-55m.

[0023] Furthermore, the embedded parts of the north bank anchor are arranged in three rows, in the order from the edge to the inside: the first row, 2 main cable anchor embedded parts and 4 wind cable anchor embedded parts; the second row, 2 main cable anchor embedded parts; the third row, all traction cable steering embedded parts and lifting cable anchor embedded parts; each row of anchors is arranged symmetrically according to the center line of the upstream and downstream main cables and the longitudinal center line of the bridge; the main cable anchor embedded parts are buried obliquely in the north bank anchor, and the traction cable steering embedded parts and the lifting cable anchor embedded parts are buried vertically in the north bank anchor.

[0024] Furthermore, the cable tower includes two groups of tower columns, which are divided into left and right sections; each tower column is composed of 4 steel pipe column columns + connecting cross bars + connecting diagonal bars; the columns are connected by multiple groups of segments through flanges, and the connecting cross bars and connecting diagonal bars are welded to the columns; upper and lower cross braces are arranged between the tower columns to connect the tower columns into a whole, and a full-length top cross beam is arranged on the top of the tower columns, and 4 wind cable tower top anchoring devices and 2 temporary saddles are symmetrically arranged on the top cross beam along the longitudinal center line of the bridge, and the wind cable tower top anchoring devices are symmetrically arranged on both sides of the temporary saddle.

[0025] Furthermore, the spacing between the anchoring devices on the top of the wind cable towers on both sides of the same temporary saddle is smaller than the spacing between the two wind cable anchoring embedded parts on the same side, so that the wind cable is not perpendicular to the transverse direction of the bridge.

[0026] Furthermore, the tensioning end of the wind cable is arranged at the top of the cable tower, and the anchoring device on the top of the wind cable tower includes a wind cable anchor seat, a CNC jack and a wind cable anchor. The upper end of the wind cable passes through the wind cable anchor seat, the wind cable anchor and the CNC jack in sequence, and is tensioned by the CNC jack.

[0027] Furthermore, the overhead crane placement platform is fixed by welding through an embedded part N1 embedded in the top surface of the upper cross beam of the main tower and an embedded part N2 embedded in the side surface of the upper cross beam of the main tower.

[0028] The beneficial effects of the present invention are:

[0029] The present invention makes full use of existing permanent structures such as existing anchors and main towers, which not only reduces the cost of engineering materials and the amount of engineering work required to build a cable crane, but is also environmentally friendly and has little impact on the terrain. At the same time, the structural strength of the cable tower itself and the alternating installation of the main cable and wind cable are used to control the unbalanced horizontal force on the top of the cable tower, thereby meeting the requirements of safe lifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0031] Figure 1 This is a vertical layout diagram of a cable crane according to an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of the cable crane layout according to an embodiment of the present invention.

[0033] Figure 3 This is a vertical layout diagram of the wind cable according to an embodiment of the present invention.

[0034] Figure 4 This is a plan view of the wind cable layout according to an embodiment of the present invention.

[0035] Figure 5 Schematic diagram of the cable tower structure according to an embodiment of the present invention.

[0036] Figure 6 This is a schematic diagram of the installation of a wind cable according to an embodiment of the present invention.

[0037] Figure 7 The figure is a layout diagram of some embedded parts in the half-width north bank anchorage according to an embodiment of the present invention.

[0038] Figure 8 for Figure 7 Schematic diagram of the structure of the main cable anchor embedded parts and the wind cable anchor embedded parts.

[0039] Fig. 9 This is an anchoring diagram of the embedded parts in the south bank anchorage according to an embodiment of the present invention.

[0040] Fig.10 This is an anchoring diagram of a lifting cable according to an embodiment of the present invention anchored on the south bank.

[0041] Fig.11 This is an anchoring diagram of a traction cable according to an embodiment of the present invention anchored on the south bank.

[0042] Fig.12 It is a structural schematic diagram of the overhead travelling crane placement platform according to an embodiment of the present invention.

[0043] Fig.13 This is a vertical view of the north bank anchorage according to an embodiment of the present invention.

[0044] In the figure: 1-main tower, 2-cable tower, 3-north bank anchor, 4-south bank anchor, 5-wind cable, 6-main cable, 7-traction cable, 8-hoisting cable, 9-cable support, 10-temporary saddle, 11-cable tower anchor embedded parts, 12-main cable anchor embedded parts, 13-traction cable steering embedded parts, 14-hoisting cable anchor embedded parts, 15-wind cable anchor embedded parts, 16-overhead crane, 17-catwalk , 18-hoisting winch, 19-traction winch, 20-protective shed, 21-upper crossbeam of main tower, 22-embedded part N1, 23-embedded part N2, 24-overhead crane placement platform, 25-wind cable tower top anchoring device, 26-operating platform, 27-wind cable anchor seat, 28-CNC jack, 29-wind cable anchor, 30-main cable, 31-hoisting cable steering, 32-traction cable steering. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0046] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0047] Next, the method of the present invention is described by taking a bridge across the Yellow River in a certain project as an example.

[0048] like Figure 1 , Figure 2 As shown in the figure, the bridge across the Yellow River is located in a mountainous and hilly area. It is a single-tower ground-anchored revolving cable suspension bridge with a main span of 510m, built on the north and south banks of a section of the Yellow River. Only the main tower 1 is set on the south bank. The main tower 1 adopts a reinforced concrete portal frame structure and the height of the main tower 1 is 109m. A prestressed concrete box beam of equal height (i.e., the main tower upper beam 21) is set on the upper part of the main tower 1.

[0049] like Figure 1 , Figure 2As shown, the cable crane mainly includes an anchor, an anchoring system, a cable tower 2, a temporary saddle 10, a main cable 6, a crane system, a lifting cable 8, a traction cable 7, an operating system, a command and communication system, and a construction monitoring system. In this embodiment, the rated lifting capacity of the cable crane is 2×145t, and the lifting blind area of ​​the south bank and the north bank is 15m. A total of 22 main cables 6 are provided, 11 main cables 6 are provided on the upstream and downstream sides respectively, and each set of main cables 6 is provided with 2 cranes 16, each crane 16 is provided with two lifting systems, and each set of main cables 6 is provided with a traction cable system.

[0050] The crane system includes crane 16, upper pylon, lower pylon and other components. Each cable hanger is equipped with two crane systems. The cranes 16 are connected by steel wire ropes with a spacing of 7.5m. The crane system is equipped with 26 load-bearing wheels, 2 traction wheels and 5 lifting wheels.

[0051] In the construction of the Yellow River Bridge in this embodiment, the cable crane anchorage is greatly affected by the position of the main tower 1 and the terrain conditions, and there are many restrictions. In this regard, in the embodiment of the present invention, a detailed survey of the site topography is conducted, the cable crane design and construction are comprehensively considered, and the anchorage structures on both sides are fully utilized as the anchorage of the cable crane. No main cable anchorage is set separately, which reduces the impact of terrain conditions and alleviates the construction difficulty; during the anchorage pre-embedded construction, the quality control of the embedded parts is strengthened to ensure that the cable anchorage meets the structural safety.

[0052] like Figures 1 to 12 As shown, the cable crane of the present invention adopts gravity anchoring + asymmetric unequal height double tower solution, the two towers are cable tower 2 and main tower 1, wherein the height of cable tower 2 is lower than that of main tower 1. The cable tower 2 with this structure does not need to be built as high as the main tower 1, and the cable tower can be dismantled after use to reduce the amount of engineering; secondly, the main tower 1 is a permanent structure, and the main tower 1 is high and the cable tower 2 is low, so that the main tower 1 plays a greater role in bearing, which is not only conducive to improving construction efficiency, but also reduces construction difficulty and saves construction costs; thirdly, the north bank anchor 3 and the south bank anchor 4 are permanent structures, and the cable of the cable crane is anchored to the anchors on both sides through embedded parts, which is convenient for construction, saves costs and has little impact on the topography.

[0053] Next, the construction method of the asymmetric unequal height structure cable crane of the present invention will be described by taking the above-mentioned Yellow River Bridge as an example.

[0054] A construction method for an asymmetric unequal height structure cable crane comprises the following steps:

[0055] Step 1: Cable crane anchoring structure and embedded parts construction:

[0056] During the construction of the north bank anchorage 3 and the south bank anchorage 4, the cable hoist-related embedded parts are embedded, including the main cable anchor embedded parts 12, the wind cable anchor embedded parts 15, the lifting cable anchor embedded parts 14, the traction cable steering embedded parts 13 and the cable tower anchor embedded parts 11; the temporary cable saddle anchor and embedded parts (main cable anchor embedded parts system and traction cable and lifting cable steering embedded parts system) at the top of the south main tower are constructed simultaneously. Figures 1 to 9 Shows the relevant embedded parts after construction.

[0057] Step 2: Assemble North Shore Cable Tower 2:

[0058] Use the north bank tower crane to assemble cable tower 2; after assembling the 5th and 10th sections of the north bank cable tower 2, install the cross brace between the columns in time; pay attention to controlling the verticality of the tower column, the column inclination is less than H / 1000 and not more than 10mm; after the tower column is installed, use the tower crane to install the top beam in sections; pay attention to controlling the elevation and displacement during the installation process. Figures 3 to 5 9 above shows the structure of the cable tower 2.

[0059] Step 3: Temporary saddle 10 installation and temporary suspension of overhead crane:

[0060] According to the lifting capacity of the main tower crane, the temporary saddle 10 is hoisted in parts, and the traction rope and the hoisting rope steering embedded parts system are installed; the crane shelving platform 24 is installed on the side of the main tower upper beam 21 facing the north bank; the crane 16 is lifted and temporarily fixed on the crane shelving platform 24. The crane shelving platform 24 is connected and fixed by the embedded parts N1 22 embedded in the top surface of the main tower upper beam 21 and the embedded parts N2 23 embedded in the side of the main tower upper beam. Fig.12 The overhead crane 16 is in a state of being temporarily shelved on the overhead crane shelving platform 24 .

[0061] Step 4: Temporary traction system installation:

[0062] In the previous stage of erecting catwalk 17, a Φ32 steel wire rope was erected using the upstream and downstream catwalk traction systems as a temporary traction system for cable crane construction. The steel wire rope was temporarily fixed to the positions of the upstream and downstream inner handrails during the installation of the catwalk system. When the catwalk gantry was installed, the Φ32 steel wire rope was manually assisted to be placed on the outside of the gantry.

[0063] In this step, after the 15t winch of the temporary traction system (installed on the south bank approach bridge), the north bank anchor horizontal steering wheel, and the (south bank) bridge deck horizontal steering wheel are installed in place, the Φ32 steel wire rope is respectively installed into the horizontal steering wheel and the temporary traction winch, and then the connection between the steel wire rope and the handrail cable is released, and the two 15t winches of the traction system are activated to adjust the verticality and linearity of the temporary traction system to form a large-circulation traction system.

[0064] Step 5: Installation of main cable 6 and wind cable 5:

[0065] The single main cable 6 is wound on the drum, hoisted to the cable-laying frame by a crane, and the main cable 6 is temporarily connected to the traction cable 7, leaving enough rope head length, and the temporary traction winch is started to pull the main cable 6 to the top of the main tower 1. After the rope head of the main cable 6 is manually assisted to pass through the main cable 6 saddle and the overhead crane 16, the rope head of the main cable 6 is temporarily connected to the traction cable of the temporary traction system again, and the temporary connection on the side span side is released, and the main cable 6 is continued to be pulled to the north bank cable tower 2, and the temporary cable saddle 10 is passed through in the same way, and the main cable 6 is continued to be pulled to the north bank anchor 3, and the connection is removed, and the rope head of the main cable 6 is anchored on the anchor beam device of the main cable anchor embedded part 12, and the main cable 6 at the south bank end is pulled back until the main cable 6 basically reaches the vertical position of the empty cable; all the main cables 6 on the cable-laying frame on the south bank are released, and the ends are anchored on the adjusting pulley group, and the tightening pulley group on the south bank is adjusted to make the verticality of the main cable 6 reach the designed verticality of the empty cable, and the initial adjustment is completed, and the erection of one main cable is completed;

[0066] Repeat the above steps to complete the installation of the remaining 21 main cables; the main cable 6 uses Ф60mm steel wire rope (6×37WS+IWR), with a total of 22 cables (11 on one side); during the installation of the main cables, the main cables 6 and wind cables 5 need to be installed alternately to control the unbalanced horizontal force on the top of the cable tower 2; construction process: install 2×5 main cables → install 2×1 bundle of wind cables → install 2×6 main cables → install 2×1 bundle of wind cables; the wind cable uses 2-2×7-φ15.2 steel strands (1860MPa), with a single bundle initial tension of 28.98t, and is tensioned using a CNC jack 28, which can display the tension value digitally. During the tensioning of the cable tower wind cable 5, dual control of the tensioning force and the tower top deviation is adopted; the tensioning end of the wind cable 5 is set at the top of the cable tower; the cable tension must be measured with a dynamometer during the tensioning and adjustment of the wind cable 5 to ensure that the final cable tension is consistent with the design. Figures 1 to 6 The installed wind cable 5 and main rope 6 are shown.

[0067] Step 6: Install the traction rope 7 and the lifting rope 8:

[0068] Install the traction rope 7: manually pull one end of the traction rope to the bottom of the main tower 1, use the tower crane to lift the wire rope end to the top of the main tower 1, and temporarily fix it; manually assist the traction rope 7 to pass through the traction rope steering wheel on the saddle of the main rope 6 and the overhead crane traction wheel to be pulled back to the anchor for guidance, and then pass through the saddle traction steering wheel and the overhead crane traction wheel again. After the traction rope "walk 8" arrangement is completed, the traction rope 7 is pulled downward to the bridge deck steering wheel, and one end of the rope enters the traction winch 19, and the other end of the rope enters another traction winch 19 in the same group; repeat the above installation steps to complete the installation of the remaining traction ropes 7;

[0069] Install the lifting cable 8: transport the lower bracket to the bottom of the overhead crane 16 by the tower crane, temporarily connect the lower bracket with a jack rope 1.5m away from the upper bracket, and release the tower crane hook; manually pull the rope head of one end of the lifting cable 8 to the bottom of the main tower 1, use the tower crane to lift the rope head of the wire rope to the top of the tower, and temporarily fix it; after the manual auxiliary lifting cable 8 passes through the lifting cable steering wheel on the temporary saddle 10, it is passed through the pulley block between the upper bracket and the lower bracket, and after passing through 10 times, the rope head is pulled out from the upper bracket and pulled into the guide wheel of the upper bracket of the overhead crane 16 in front, and then temporarily connected with the traction system, and the traction system is used to pull the rope head of the lifting cable 8 to the north bank anchor 3 for anchoring, and the other end of the lifting cable 8 enters the lifting winch 18; start the lifting winch 18 to raise the lower bracket by about 30cm, and release the jack rope connecting the upper bracket and the lower bracket; repeat the above installation steps to complete the installation of the remaining lifting cables 8.

[0070] Step 7: Fine-tune and test-hang the main cable 6;

[0071] Move the crane 16 to the middle of the span, and adjust it according to the initial adjustment method to make the verticality of the main cable 6 consistent with the designed installation verticality. After all the main cables 6 are adjusted, make the crane 16 run back and forth for one round across the entire span; move the crane 16 to the middle of the span, measure the offset of the top of the cable tower 2 column, and adjust the cable force of the wind cable 5 to control the deviation of the top of the cable tower accordingly; pull the crane 16 to the front of the tower and make a second adjustment according to the initial adjustment method to make the verticality of the main cable 6 consistent and keep it flush, with the relative error controlled within 10cm; after the cable crane is assembled and accepted, a trial hoist can be carried out; it can be put into use only after confirming that everything is normal; if Figure 1 to Figure 2 The complete cable crane structure is shown.

[0072] The cable crane acceptance is carried out on the construction quality of the cable crane system according to the "Cable Crane" (TB / T 28756-2012), "Technical Specifications for Highway Bridge and Culvert Construction" (JTG / T 3650-2020), "Technical Code for Construction of Cable Cranes" Q / CCCC GL208-2019 and relevant design drawings of the cable crane; after the cable crane has been used for a period of time, the verticality of the main cable is readjusted to eliminate the influence of the inelastic deformation of the main cable; this work is carried out regularly; at the same time, during the operation of the cable crane, the deviation of the top of the cable tower is regularly observed and the wind cable force is adjusted to be within the specified range (-43mm~+40mm).

[0073] The north bank span of the cable crane is small, the vertical angle of the main cable 6 is large, and the eccentric load of the cable tower 2 is large, so the wind cable 5 must be used. The wind cable 5 is only arranged on the north side of the north bank anchor 3. The wind cable 5 is anchored on the outside of the main cable anchor embedded part 12 at the north bank anchor 3. The tensioning ends of the wind cable 5 are all set at the top of the cable tower. The main loads of the wind cable 5 are the deadweight of the structure, the initial tension of the wind cable and the wind load. The initial tension of the wind cable is 4.14t×7. The wind cable 5 controls the wind force level of 6 in the working state and 10 in the non-working state. The installation of the wind cable 5 includes the following steps:

[0074] Step 1, installing the cable tower 2 and laying out the operating platform 26 on the top of the cable tower 2;

[0075] Step 2: Use a lifting device to lift the temporary saddle 10 to the top of the cable tower 2 in parts;

[0076] Step 3, 1-5# main cable installation:

[0077] Install 1-5# main cables simultaneously upstream and downstream, and preliminarily adjust the cable force and sag of main cable 6; without considering the wind load, after all 1-5# main cables are tensioned in place, the top of cable tower 2 will deform longitudinally by 17mm (biased towards the mid-span side); the wind speed during installation and tensioning shall not exceed level 6, and the maximum difference in the number of main cables installed and tensioned upstream and downstream shall not exceed 2;

[0078] Step 4: Installation and tensioning of 1# and 4# wind cables:

[0079] A wind cable tower top anchoring device 25 is installed on the top of the cable tower 2. Four wind cable tower top anchoring devices 25 are set corresponding to the four wind cables 5, namely 1#-4# wind cable tower top anchoring devices. The wind cable tower top anchoring devices 25 are respectively set on both sides of the temporary saddle 10; 1# and 4# wind cables are installed and tensioned synchronously, and each bundle uses 7-φ15.2 steel strands with an initial tension of 7×4.14t; it is required that the upstream and downstream are tensioned synchronously and symmetrically, and the wind speed during tensioning shall not be greater than level 6; without considering the effect of wind load, after the two wind cables 5 are tensioned in place, the top of the cable tower 2 is longitudinally deformed by 16mm (biased towards the side span side); the wind cable tower top anchoring device 25 includes a wind cable anchor seat 27, a CNC jack 28 and a wind cable anchor 29, and the upper end of the wind cable 5 passes through the wind cable anchor seat 27, the wind cable anchor 29 and the CNC jack 28 in sequence;

[0080] Step 5, 6-11# main cable installation:

[0081] Install and tension the 6-11# main cables simultaneously upstream and downstream, and fine-tune the cable force and sag of the 1-11# main cables; without considering the wind load, after all cables are tensioned in place, the top of the cable tower 2 will deform longitudinally by 2mm (biased towards the mid-span side); the wind speed during installation and tensioning must not exceed level 6, and the maximum difference in the number of 6 main cables installed and tensioned upstream and downstream should not exceed 2;

[0082] Step 6: Installation and tensioning of 2# and 3# wind cables 5:

[0083] Synchronously install and tension the 2# and 3# wind cables 5. Each cable uses 7-φ15.2 steel strands with an initial tension of 7×4.14t. Synchronously tension the upstream and downstream cables 5 symmetrically, and the wind speed should not exceed level 6 during tensioning. Without considering the wind load, the top of the cable tower 2 will deform 24mm longitudinally (towards the side span) after the two wind cables 5 are tensioned in place. Figure 3 , Figure 4 Schematic diagram of the wind cable 5 after installation.

[0084] The offset during the installation of the wind cable is the deformation of the cable tower calculated by the software model according to the best construction steps. Specifically, the spatial finite element model is established using the structural analysis software midas to calculate the longitudinal and transverse displacement results of the cable tower under various wind cable and main cable installation conditions, and the solution with the smallest longitudinal displacement offset is selected; this method of alternating the main cable 6 and wind cable 5 can ensure the safety of the wind cable 5, main cable 6 and cable tower 2 during the entire installation process.

[0085] During the adjustment of the main cable 6, the sag is the main control and the cable force is the auxiliary control (a force measuring device is installed on the main cable 6). The traction speed of the tensioning winch is controlled during the cable adjustment. The cable adjustment result should meet the requirements that a single main cable 6 should be located in the same vertical plane, the same group of main cables 6 should be parallel to each other, and the sag error should be ≤10cm (the total station is used to directly control the cable elevation using trigonometric elevation). At the same time, the initial horizontal tension of the empty cable should meet the design requirements. When the mid-span sag meets the design and specification requirements, the main cable 6 is anchored.

[0086] From Figure 4 It can be seen from the plan view that the spacing between each pair of wind cable anchor embedded parts 15 is greater than the spacing between each pair of wind cable tower top anchor devices 25, so that the wind cable 5 is not parallel to the longitudinal center line of the bridge. From the plan view, the wind cable 5 is not perpendicular to the transverse direction of the bridge. In this embodiment, the wind cable 5 is arranged according to the spatial dimensions of the site, and the angle between the wind cable and the transverse direction of the bridge is 88.9°. The adjacent side wind cables 5 are arranged symmetrically to balance their own horizontal force components.

[0087] The winches involved in this embodiment are divided into three types: traction winches 19, hoisting winches 18, and temporary traction system winches, all of which are arranged on the bridge deck of the south bank approach bridge. The traction winches 19 are 4 25t friction winches, the hoisting winches 18 are 4 15t single-drum winches, and the temporary traction system winches use 2 25t single-drum traction winches. Fig.10 , Fig.11 As shown, various types of winches are symmetrically arranged on both sides of the south bank approach bridge deck.

[0088] The cable hanging anchors all use the existing gravity anchors on both sides of the river, and the anchors on both sides adopt the block and layer construction method. Figure 1-Figure 5 , Fig.13 As shown in the figure, due to the terrain restrictions and based on the principles of structural safety and minimizing the impact on the environment, the North Bank Anchor 3 adopts a surface-covered gravity anchor, which is 61.5m long, 45m wide, 36.03m high in the north direction, and 37.32m high in the south direction. The bottom surface is designed as a concave and convex step tooth block shape, and the horizontal and vertical directions are designed as four steps; the North Bank Anchor 3 is constructed with 4 anchor blocks in the front, back, left and right directions. The North Bank Anchor 3 is divided into 18 construction layers in the height direction, each layer is 2.0m thick, and is divided into 4 areas in the horizontal direction. The total amount of concrete is 73,100 m³. South Bank Anchor 4 adopts gravity rock-embedded anchor, which is 58m long, 60m wide and 43.3m high in the north direction. The lower part of South Bank Anchor 4 is excavated into multiple steps, and a base is set at the bottom of the front side of the anchor, forming a closed system with the rear anchor body and the side saddle room. South Bank Anchor 4 is constructed with two anchor blocks on the left and right, with a total of 24 construction layers in the height direction and 2 areas in the horizontal direction. The South Bank cable saddle part has 9 layers; each layer is 2.0m thick and the total amount of concrete is 93,400 m³. The approach bridges on the north and south banks are prefabricated T-beam approach bridges.

[0089] like Figures 1 to 8 As shown, the main cable 6 (load-bearing cable), the lifting cable 8, the traction cable steering embedded part 13 and the north end of the wind cable 5 are all set on the north bank anchor 3; the south end of the main cable 6 (load-bearing cable) and the traction cable steering embedded part 13 at the south end are all set on the loose cable saddle pier of the south bank anchor 4, and the lifting cable steering 31, the lifting winch 18, the traction cable steering 32 and the traction winch 19 are all set on the T-beam deck of the south bank approach bridge. During the construction of the north bank anchor 3, it is necessary to embed the anchor system embedded parts, which are: ① cable tower anchor embedded parts 11; ② main cable anchor embedded parts 12; ③ traction cable steering embedded parts 13; ④ lifting cable anchor embedded parts 14; ⑤ wind cable anchor embedded parts 15. As shown in Figure 7 As shown, the embedded parts of the north bank anchor 3 are arranged in three rows, with a centerline spacing of 2m in each row, and in order from the northern edge of the north bank anchor 3 to the inside, they are: the first row, 2 main cable anchor embedded parts 12 and 4 wind cable anchor embedded parts 15; the second row, 2 main cable anchor embedded parts 12; the third row, all traction cable steering embedded parts 13 and lifting cable anchor embedded parts 14; each row of anchors is symmetrically arranged according to the center lines of the upstream and downstream main cables 6 and the longitudinal center line of the bridge; the main cable anchor embedded parts 12 are obliquely buried in the north bank anchor 3, and the traction cable steering embedded parts 13 and the lifting cable anchor embedded parts 14 are vertically buried in the north bank anchor 3.

[0090] like Fig. 9As shown, during the construction of the south bank anchor 4, embedded parts of the anchor system need to be embedded, including: ① main cable anchor embedded parts 12; ② traction cable steering embedded parts 13. Due to limited space, the north bank anchor 3 also needs to use the top surface of the anchor body as a construction platform, and set up equipment and material storage areas and lifting equipment operation areas on the platform. During the construction of the anchors on both sides, the embedded parts shall be installed in place and fixed firmly in accordance with the embedded parts layout diagram during the construction of the anchor lower structure; after the concrete strength reaches 75% of the design strength, temporary tower columns, anchors and other components shall be hoisted to the designed position of the embedded parts by lifting equipment such as automobile cranes or tower cranes for installation, and components and embedded parts, and components and components shall be connected by welding or bolts.

[0091] like Figure 1 , Fig. 9 As shown, according to the needs of on-site construction, a protective shed 20 is set up on the left side of the south bank anchor 4 near the south anchor walkway, and a steering wheel for turning the main cable 6 and the traction cable 7 is set on the top of the protective shed 20; the protective shed 20 has a clearance of 5m.

[0092] like Figure 1 , Figure 2 As shown, the main cable 6 is a three-span continuous structure. The main cable 6 is arranged in two groups, upstream and downstream, and arranged inside the main cable 30. The center spacing between the upstream and downstream main cables 6 is 17.1m. A single group of main cables 6 is composed of 11 φ60 (6×37S+IWR) steel wire ropes. The main cable 6 is a load-bearing cable. Both ends of the main cable 6 are anchored on the gravity anchors on both banks. Since the site area of ​​the south bank anchor 4 is larger, the main cable adjustment system and cable laying site are set on the south bank. The main cable north bank 3 is anchored at the north end of the anchor. The main cable anchor embedded parts 12 include anchor beams, anchor A and anchor B. Anchor A / B adopts HM588×300 steel. The anchor beam adopts a steel tube concrete structure, which is made of φ426×12mm steel tube filled with C30 concrete. There are 4 anchor beams on the north bank, 2 on the upstream and 2 on the downstream, arranged in two rows, with a row spacing of 2.0m. Each row is equipped with 4 anchor points (single set), the anchor point spacing is 0.92m, the main cable spacing is 0.46m, and the embedded angle of the anchor beam is 60°. Figure 5 , Figure 6 , Figure 7 As shown. After each row of anchoring structures on the north bank is processed into a whole, it is embedded in the north bank anchor 3 as a whole, with an anchoring depth of 2.5-3.01m. The concrete grade of the north bank anchor 3 is C40. After the main cable anchor embedded parts 12 on the south bank are processed into a whole, they are anchored on the loose cable saddle pier, with an anchoring depth of 4.0-4.73m, arranged in a row. There are 2 anchoring beams on the south bank, 1 on the upstream and 1 on the downstream. 7 anchoring points (single set) are set in a single row, with a spacing of 0.76m between anchoring points. 11 main cables 6 are anchored on each anchoring beam, with an embedded angle of 46°. The anchoring structure is as shown in the figure. Figure 8 In addition, a main cable adjustment system is set at the anchorage position on the south bank.

[0093] The traction rope 7 connects the overhead travelling crane 16 and the cable tower 2, and drives the overhead travelling crane 16 to move left and right along the main cable 6. A single traction rope is a φ38 fiber core steel wire rope, and each traction rope is arranged in a "walk 8" pattern. A traction winch 19 is set on the south bank. The maximum pulling force of a single traction rope 7 is 9.37t. Two 25t traction winches 19 are set in a single group, and there are four in total for the whole bridge. Figures 1 to 9 As shown, the upstream and downstream traction cables 7 are provided with anchoring devices and steering devices at the north end of the north bank anchor 3, the steering device is provided at the north end of the scattered cable saddle pier of the south anchor on the south bank, and the steering device and traction equipment are provided on the bridge deck of the south bank approach bridge. After the main cable 6 is adjusted, the traction cable 7 can be installed. The traction cable steering embedded parts 13 and the lifting cable anchor embedded parts 14 are made of 2[36b steel, material Q235B. The traction cable steering embedded parts 13 and the lifting cable anchor embedded parts 14 in the north bank anchor 3 are vertically buried; the traction cable steering embedded parts 13 in the south bank anchor 4 are obliquely buried in the scattered cable saddle pier, and are located obliquely below the main cable anchor embedded parts 12 on the south bank.

[0094] Furthermore, each crane 16 of the cable crane is equipped with a lifting system, and the four cranes of the whole bridge are equipped with a total of four lifting systems and four 15t winches. The lifting rope 8 is wound between the crane's movable and fixed pulley groups, and the lifting object is raised or lowered by the retraction and extension of the winch drum. A single set of lifting ropes 8 uses two φ36 fiber core steel wire ropes (6×37S+FC), arranged in 10 steps. One set of main cables 6 uses two cranes, and one crane is equipped with one set of lifting ropes 8. There are a total of four sets of lifting ropes in the whole bridge. The maximum pulling force of a single lifting rope 8 is 13.24t. Two lifting winches 18 are set for each set, and there are a total of four winches in the whole bridge. The upstream and downstream lifting ropes 8 are equipped with anchoring devices at the north end of the north bank anchor 3, and steering devices and traction equipment are set on the bridge deck of the south bank approach bridge. The lifting ropes 8 are installed after the traction ropes 7 are installed. The north bank of the hoisting cable 8 is anchored at the north end of the north bank anchor 3 (located 2.0m south of the main cable 6 anchor) through the hoisting cable anchor embedded part 14. The anchor structure adopts double 36b channel steel, with an anchor depth of 1.67m, single row setting, and a total of 2 anchor points (single set), with a spacing of 1.67m between anchor points and an embedded angle of 90°. The south bank anchor is equipped with 4 sets of steering wheels (single set) at the cast-in-place section of the top of the 3# pier of the approach bridge, and 4 hoisting winches 18 (single set) at the cast-in-place section of the top of the 3# pier of the approach bridge. Fig.10 shown.

[0095] Furthermore, the two overhead cranes 16 of each main cable 6 of the cable crane are equipped with a traction system, and the whole bridge has two traction systems, equipped with four 25t traction winches 19. The steering and anchoring devices of the traction system on the north side are all set at the north bank anchor 3, and the steering devices on the south side are all arranged on the loose cable saddle pier of the south bank anchor 4. Specifically, the north bank of the traction cable 7 is anchored at the north end of the anchor (located 2.0m south of the anchor position of the main cable 6). The anchor structure adopts double-jointed 36b channel steel, with an anchor depth of 1.67m and a single row arrangement. There are 2 anchor points (single set) in total. The spacing between the single anchor points is 1.0m, and the embedded angle is 90°; the south bank is anchored at the anchor saddle pier (located 1.7m below the anchor position of the main cable 6) with 3 sets of steering wheels (single set), 4 sets of steering wheels (single set) are set at the cast-in-place section of the top of the 4# pier of the approach bridge, and 4 25t traction winches 19 (single set) are set on the deck of the 5th span approach bridge. Fig.11 shown.

[0096] Further, such as Figures 1 to 5 As shown, the cable tower 2 is set on the north bank anchor 3, 2.25m away from the south edge of the north bank anchor 3. When pouring the top concrete of the anchor, the wind cable anchor embedded parts 15 are embedded. The wind cable anchor embedded parts 15 include embedded steel plates at the root of the columns, anchor bolts and local reinforced steel mesh (4 layers); the cable tower 2 includes two groups of tower columns, and the tower columns are connected to the cable tower anchor embedded parts 11 by welding. The bottom section of the cable tower root is welded to the embedded steel plate at the root of the column, and stiffening ribs are arranged around the column for reinforcement. The tower column is divided into left and right sections. Each tower column is composed of 4 Q345B steel pipe column columns with a diameter of φ630×20mm + connecting cross bars + connecting diagonal bars. The steel pipe columns from bottom to top are: bottom section (adjustment section) + 2×4.1m standard section A + 2.07m standard section B + 4.1m standard section A + 2.07m standard section B + 4.1m standard section A + 2.07m standard section B + 2×4.1m standard section A + top section (0.8m), with a height of about 33m. The columns are connected by multiple groups of segments through flanges. There are two standard section heights, 4.1m and 2.07m, and several adjustment sections of different lengths are also included. Adjacent segments are connected by flanges, and the transverse connection system and the diagonal connection system are welded to the columns. The transverse crossbar and diagonal bar connections of the cable tower 2 are all 2[20b channel steel, and the longitudinal crossbar and diagonal bar connections are all φ351mm×10mm steel pipes. Upper and lower cross braces are set between the tower columns to connect the tower columns into a whole. These two cross braces adopt φ351mm×10mm steel pipe truss structure. A full-length top cross beam is set at the top of the tower column. The top cross beam is welded into a box-type structure by steel plates. The top and bottom plates of the top cross beam are 20mm thick and the web plate is 20mm thick. The cross-sectional size of the top cross beam is 1000×600mm.

[0097] Further, such as Figures 1 to 5As shown, 4 sets of temporary saddles are arranged above the upper cross beam 21 of the south bank main tower and the top cross beam of the north bank cable tower 2 respectively; the temporary saddle 10 is composed of the bottom distribution beam, the hoisting cable steering wheel, the traction cable steering wheel, the main cable guide and support structure and other components. After the top embedded parts of the upper cross beam 21 of the south bank main tower and the top cross beam of the north bank cable tower 2 are installed, the installation construction of each temporary saddle 10 can be carried out. First, use a tower crane to hoist the bottom longitudinal beam of the temporary saddle 10, and weld them to the embedded parts of the upper crossbeam 21 of the main tower and the top crossbeam of the cable tower 1, and install a pad on the top of the longitudinal beam and connect it to the longitudinal beam with bolts; then hoist the saddles used for the lifting cable 8 and the traction cable switching, install them on both sides of the longitudinal beam, and weld them to the embedded parts and the top crossbeam of the cable tower 1; then hoist the upper load-bearing wheel structures of the temporary saddles 10 of the mid-span and side-span to the longitudinal beams, connect and fix them to the pads on the longitudinal beams with bolts, and set connection systems at the load-bearing wheels of the mid-span and side-span; finally, install the wind cable tower top anchoring device 25 on the top crossbeam of the cable tower 1.

[0098] Further, the installation of the overhead crane 16 includes the following steps: before pouring concrete on the cross beam 21 on the main tower, Fig.11 The embedded parts N1 22 and N2 23 used for supporting and fixing the overhead crane shelving platform 24 are required. The overhead crane shelving platform 224 is installed after the concrete strength reaches 100% of the design strength. The overhead crane shelving platform 224 is a truss platform structure, which is mainly welded by steel sections 2[25b, 2[20b, [20b. The main truss of the overhead crane 16 platform is assembled on the ground, and the pieces are hoisted to the upper crossbeam and welded and fixed with embedded parts N1 and embedded parts N2; the overhead crane shelving platform 224 steel section and embedded parts N1 22 and embedded parts N2 23 are welded with fillet welds with a welding height of hf=10mm, and the total length of the weld is 720mm. After the hoisting of the two main trusses is completed, the connecting rods of the two main trusses are installed, and finally the protective channel and railings on the top surface of the truss are installed;

[0099] Assemble the overhead crane 16 and the upper bracket on the ground, use the tower crane to hoist the first set of overhead crane 16 as a whole onto the overhead crane placement platform 224 for installation, and during the installation process, use a Ф32mm steel wire rope to temporarily fix the first set of overhead crane 16 on the tower top to prevent it from sliding down; then hoist the second set of overhead crane 16 system and temporarily fix it, set a Ф32mm steel wire rope between the two sets of overhead cranes 16 to connect them firmly, and control the length of the steel wire rope so that the center distance between the two overhead cranes 16 is basically equal to the distance between the steel truss hanging points.

[0100] Furthermore, the construction method of the asymmetric unequal height structure cable crane also includes the installation of a cable support 9. The function of the cable support 9 is to support the lifting cable 8, ensure that the lifting cable 8 does not sag on the steel truss, and ensure that the hook can fall freely when no heavy objects are lifted. Figure 1As shown, each cable support 9 is connected by a 20mm4V×39S+5FC anti-twist galvanized steel wire rope. The steps for installing the south cable support 9 are as follows: move the overhead crane 16 to the vicinity of the main tower 1, connect one end of the cable support 9 connected to the overhead crane 16; install the cable support 9 in sequence and pull the overhead crane 16 to the north at the same time, and complete the installation of the 9 cable supports 9 on the south side; the end of the connecting rope of the south cable support 9 is not anchored for the time being. The steps for installing the north side cable support 9 are as follows: pull the overhead crane 16 to the vicinity of the north bank tower column, and connect one end of the cable support 9 to the overhead crane 16; install the cable supports 9 in sequence and pull the overhead crane 16 to the south side synchronously, install 13 cable supports 9, and anchor the end of the steel wire rope connected to the cable support 9 to the north bank anchor 3; pull the overhead crane 16 to the vicinity of the tower column, and anchor the connecting rope of the south side cable support 9 to the steering saddle at the top of the tower; set a steel rigid connection between the first cable support 9 on both sides near the overhead crane 16 and the overhead crane 16.

[0101] Furthermore, the construction method of the asymmetric unequal height structure cable crane also includes a cable crane dismantling method. The cable crane dismantling construction process is: pre-dismantling inspection → dismantling the cable support 9 and the connecting rope → restoring the temporary traction system → dismantling the lifting cable 8 and the lower bracket of the overhead crane 16 → dismantling the traction cable 7 → dismantling the main cable 6 → dismantling the temporary traction system → dismantling the overhead crane 16 system → dismantling the temporary saddle 10 → dismantling the temporary cable tower 2 → dismantling the embedded parts and concrete surface treatment.

[0102] In the present invention, the cable crane is the main lifting equipment for lifting the main beam segment. Only a cable tower is set at the north bank anchor. The height is minimized to reduce the cost of raw materials and the amount of installation and removal work while meeting the lifting requirements. There is no cable tower on the south bank side, and the main cable saddle is placed on the top of the main tower; the cable tower is about 33m high, and the main tower is 109m high. The unbalanced force on the cable tower caused by the large height difference between the cable tower and the main tower is balanced by its own structural strength and wind cable. After calculation under various working conditions, it can meet the requirements of safe lifting. Taking advantage of the heavy weight of the permanent anchor itself, there is no need to add a temporary anchor of the cable crane, which saves costs and reduces the impact on the environment; at the same time, the main cable, traction cable, and lifting cable are guaranteed to meet the lifting requirements through the reasonably designed and arranged anchoring structure.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A construction method for an asymmetric unequal height structure cable crane, characterized in that: The steps include: Step 1: Construction of cable crane anchoring structure and embedded parts; During the construction of north bank anchoring and south bank anchoring, embedded cable crane related embedded parts are embedded, including main cable anchor embedded parts, wind cable anchor embedded parts, lifting cable anchor embedded parts, traction cable steering embedded parts and cable tower anchor embedded parts; the cable tower anchor embedded parts are set on the south side of the north bank anchoring, and the wind cable anchor embedded parts are buried on the north side of the north bank anchoring; the main tower is set on the south bank side; Step 2: Assemble the cable tower on the north bank; assemble the cable tower using the lifting equipment on the north bank; the cable tower includes two groups of tower columns, which are divided into left and right sections; each tower column consists of 4 steel pipe column columns + connecting cross bars + connecting diagonal bars; the columns are connected by multiple groups of segments through flanges, and the connecting cross bars and connecting diagonal bars are welded to the columns; upper and lower cross braces are set between the tower columns to connect the tower columns into a whole, and a full-length top cross beam is set on the top of the tower column. Four wind cable tower top anchoring devices and two temporary saddles are symmetrically arranged on the top cross beam along the longitudinal center line of the bridge, and the wind cable tower top anchoring devices are symmetrically arranged on both sides of the temporary saddle; Step 3: Install temporary cable saddle and temporarily shelve the overhead crane; use the main tower crane to hoist the temporary cable saddle, and install the diverting pulleys of the traction rope and the lifting rope on the upper beam of the main tower; install the overhead crane shelving platform on the side of the upper beam of the main tower facing the north bank, lift the overhead crane, and temporarily fix the overhead crane on the shelving platform; Step 4: Installation of temporary traction system: Install temporary traction winch and bridge deck horizontal steering wheel on the south bank approach bridge, and install north bank anchor horizontal steering wheel on the north bank anchor; then manually install the traction system wire rope installed on the outside of the catwalk portal during the catwalk erection stage into the north bank anchor horizontal steering wheel, bridge deck horizontal steering wheel, and temporary traction winch to form a large-circulation traction system; Step 5: Main cable installation and wind cable installation; Main cables and wind cables are installed alternately to control the unbalanced horizontal force on the top of the cable tower; there are 11 main cables on one side and 4 wind cables; the construction process of alternating main cables and wind cables is: install 2×5 main cables → install 2×1 wind cable → install 2×6 main cables → install 2×1 wind cable; The tensioning is carried out by using a CNC jack, which can display the tensioning force digitally. After each main cable is installed, it is adjusted so that the main cable sag reaches the designed empty cable sag, completing the initial adjustment. Step 6: Install the traction rope and lifting rope; Step 7: Fine-tune the main rope and conduct trial lifting.

2. The construction method of asymmetrical unequal height structure cable crane according to claim 1, characterized in that: In step 5, the alternating installation of the main cable and wind cable includes the following steps: (1) Installation of 1-5# main cables: Install 1-5# main cables simultaneously upstream and downstream, and preliminarily adjust the main cable force and sag. Without considering the wind load, after all 1-5# main cables are tensioned in place, the top of the cable tower is longitudinally deformed by 17mm toward the mid-span side. (2) Installation and tensioning of 1# and 4# wind cables: Install the wind cable tower top anchor device on the top of the cable tower. Four wind cable tower top anchor devices are set up corresponding to the four wind cables, namely 1#-4# wind cable tower top anchor devices. The wind cable tower top anchor devices are set up on both sides of the temporary saddle respectively. Install and tension 1# and 4# wind cables synchronously upstream and downstream. Each bundle uses 7-φ15.2 steel strands. The initial tension of a single bundle is 28.98t. After the two wind cables are tensioned in place, the top of the cable tower is longitudinally deformed by 16mm towards the side span. (3) Installation of 6-11# main cables: Install and tension 6-11# main cables simultaneously upstream and downstream, and fine-tune the force and sag of 1-11# main cables; after all main cables are tensioned in place, the top of the cable tower will be longitudinally deformed by 2mm toward the mid-span side; (4) Installation and tensioning of 2# and 3# wind cables: 2# and 3# wind cables are installed and tensioned synchronously and symmetrically upstream and downstream. After the two wind cables are tensioned into place, the top of the cable tower is longitudinally deformed by 24 mm towards the side span.

3. The construction method of asymmetrical unequal height structure cable crane according to claim 1, characterized in that: The size of the north bank anchor is smaller than that of the south bank anchor. The north bank anchor has the following embedded parts: ① cable tower anchor embedded parts; ② main cable anchor embedded parts; ③ traction cable steering embedded parts; ④ lifting cable anchor embedded parts; ⑤ wind cable anchor embedded parts; the south bank anchor has the following embedded parts: ① main cable anchor embedded parts; ② traction cable steering embedded parts; the south bank anchor is also equipped with a main cable adjustment system and a cable laying site.

4. The construction method of asymmetrical unequal height structure cable crane according to claim 3, characterized in that: The north bank anchor is a surface-covered gravity anchor, and the bottom surface of the north bank anchor is designed as a concave and convex stepped tooth block; the cable tower anchor embedded parts are 2-2.5m away from the south edge of the north bank anchor; in the north bank anchor, the main cable anchor embedded parts, the towing and protection cable steering embedded parts, the lifting cable anchor embedded parts, and the wind cable anchor embedded parts are 4-8m away from the north edge of the north bank anchor; the distance from the cable tower anchor embedded parts to the wind cable anchor embedded parts is 48-55m.

5. The construction method of asymmetrical unequal height structure cable crane according to claim 3, characterized in that: The embedded parts of the north bank anchor are arranged in three rows, in the order from the edge to the inside: the first row, 2 main cable anchor embedded parts and 4 wind cable anchor embedded parts; the second row, 2 main cable anchor embedded parts; the third row, all traction cable steering embedded parts and lifting cable anchor embedded parts; each row of anchors is arranged symmetrically according to the center line of the upstream and downstream main cables and the longitudinal center line of the bridge; the main cable anchor embedded parts are buried obliquely in the north bank anchor, and the traction cable steering embedded parts and lifting cable anchor embedded parts are buried vertically in the north bank anchor.

6. The construction method of asymmetrical unequal height structure cable crane according to claim 1, characterized in that: The spacing between the anchoring devices on the top of the wind cable towers on both sides of the same temporary saddle is smaller than the spacing between the two wind cable anchor embedded parts on the same side, making the wind cable non-perpendicular to the transverse direction of the bridge.

7. The construction method of asymmetrical unequal height structure cable crane according to claim 1, characterized in that: The tensioning end of the wind cable is arranged at the top of the cable tower. The anchoring device at the top of the wind cable tower includes a wind cable anchor seat, a CNC jack and a wind cable anchor. The upper end of the wind cable passes through the wind cable anchor seat, the wind cable anchor and the CNC jack in sequence and is tensioned by the CNC jack.

8. The construction method of asymmetrical unequal height structure cable crane according to claim 1, characterized in that: The overhead crane resting platform is fixed by welding through an embedded part N1 embedded in the top surface of the upper cross beam of the main tower and an embedded part N2 embedded in the side surface of the upper cross beam of the main tower.

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