Construction method for installing whole tied-arch bridge by cable crane

Abstract

The application discloses a construction method for integrally installing a tied-arch bridge by using a cable crane, which comprises the following steps: S1, on-site integral assembly; S2, synchronous cable system setting; S3, tied-arch upper loading and temporary support disengagement; S4, tied-arch integral transportation; S5, cable crane hoisting and river crossing; and S6, system conversion and final installation. The tied-arch is integrally assembled on land behind the abutment, and a collaborative installation method of "railway vehicle land transportation" and "asymmetrical tower cable crane traction" is combined, so that the high-precision and high-risk assembly and erection operation is successfully decomposed into two safe and controllable steps of ground prefabrication and air integral positioning, which greatly improves the construction safety and the component quality, and compresses the occupancy time of the external environment such as a waterway to the shortest, realizes the safe, efficient and high-precision construction target, and is particularly suitable for the construction of a long-span bridge crossing a river, a valley and other unfavorable terrains.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering construction technology, and in particular to a construction method for installing a tied-arch bridge using cable hoisting. Background Technology

[0002] Tie-arch bridges, as a type of bridge with a beautiful appearance and reasonable structure, form a self-balancing system by balancing the horizontal thrust of the arch feet through tie rods. They have low requirements for the foundation and are widely used in my country's infrastructure construction, especially in small and medium-span bridge projects, where they have strong applicability and competitiveness. They are often used to cross rivers, highways, and other scenarios. As the core main load-bearing component of a tie-arch bridge, the safety, economy, efficiency, and impact on the surrounding environment of the arch rib installation directly determine the construction quality, schedule, and overall cost of the entire bridge project. Therefore, the rational selection of the arch rib installation method is crucial.

[0003] Currently, the construction of the arch ribs of small and medium-span tied arch bridges mainly adopts three conventional techniques: the scaffolding method, the integral jacking method, and the floating crane integral lifting method. However, each technique has obvious limitations and cannot meet the construction needs of specific scenarios. Although the scaffolding method is a mature construction method, it requires the erection of a full-span scaffold at the bridge site, which will significantly occupy navigation space, often requiring long-term navigation closures. In addition, it consumes a lot of materials and has a long construction period, making it unsuitable for construction scenarios that require ensuring navigation. Although the integral jacking method has less impact on navigation than the scaffolding method, it requires the setting up of temporary supports in the water, which still occupies navigable water areas and increases construction costs. Moreover, the stability of temporary supports is greatly affected by hydrogeological conditions, making it unsuitable for scenarios with high navigation guarantee requirements. The floating crane integral lifting method does not require the erection of scaffolding or temporary supports, but it is highly dependent on large floating crane equipment, with high costs for equipment rental and transportation, and it cannot be implemented in remote areas lacking large lifting equipment.

[0004] In actual engineering construction, many small and medium span tied arch bridge sites are located in busy waterways, requiring strict protection of navigation conditions, making the support method and overall jacking method unsuitable; at the same time, some bridge sites are located in remote areas, lack large floating crane equipment, or have excessively high equipment costs, making the overall floating crane hoisting method difficult to implement.

[0005] Therefore, a construction method for installing tied-arch bridges using cable-stayed cranes is proposed to address the problems existing in the current technology. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems by providing a construction method for the integral installation of tied-arch bridges using cable-stayed cranes. This invention successfully breaks down the high-precision, high-risk assembly and erection work into two safe and controllable steps: ground prefabrication and aerial placement, by assembling the tied-arch bridge entirely on land behind the abutments and combining "land transport by railcar" with "asymmetric tower cable-stayed crane traction." This significantly improves construction safety and component quality, and minimizes the time spent occupying waterways and other external environments, achieving safe, efficient, and high-precision construction goals. It is particularly suitable for the construction of large-span bridges spanning rivers, canyons, and other unfavorable terrain. To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: According to one aspect of the present invention, a construction method for integrally installing a tied-arch bridge using cable hoists is provided, comprising the following steps: S1. On-site assembly: At the selected site behind the abutment, a complete tied arch structure is assembled using the bracket method. Temporary support pads are provided at the bottom of the tied arch, and transport components are set at the bottom. S2. Synchronous installation of the cable system: Cable towers are installed on the banks on both sides of the tie arch, and the main span of the cable crane is greater than the main span of the tie arch; wherein, the cable towers are configured asymmetrically, specifically: the height of the cable tower on the side away from the tie arch assembly site is lower than the height of the cable tower on the side closer to the assembly site; S3. Loading and unloading the tie arch from the temporary support: The assembled tie arch is lowered onto the transport assembly, which includes a railcar. The two railcars set at the front and rear work together to lift the tie arch so that it is detached from the bottom pad. Then all the pads are removed. S4. Overall transportation of the tied arch: The transportation component is equipped with rails, and two railcars work together to move along the rails to transport the tied arch to the lifting area of ​​the cable crane; S5. Cable crane lifting and pulling across the river: Using a cable system in conjunction with the tie arch, the front end of the tie arch is lifted to a set height and the railcar is withdrawn; then, the tie arch is pulled across the river to the other side via the cable system, while the railcar behind continues to support the transport. S6. System Conversion and Final Installation: Remove temporary supports and track vehicles, complete the system conversion of the tie-arch from a temporary support state to a permanent structure, and achieve final installation.

[0007] Preferably, the transport component in S1 includes a sliding track on a cable tower located near the assembly site, two pads on the sliding track, and two railcars on the sliding track, with the tie rod arch temporarily placed on the two pads.

[0008] Preferably, the cable system in S2 includes two cable towers, each cable tower has a main pier on its opposite side in front, each main pier has a temporary support, two cable gantry cranes are provided between the two cable towers, and two anchorages are provided outside each cable tower, with the two ends of the two cable gantry cranes respectively connected to the corresponding anchorages.

[0009] Preferably, in S2, when the cable crane towers are asymmetrically configured, the tower height on the side away from the assembly yard is 10% to 30% lower than the tower height on the side closer to the assembly yard, so as to ensure that the angle between the traction rope and the ground is maintained within the range of 30° to 60° during the forward movement of the cable crane, thereby providing a more stable pulling force.

[0010] Preferably, in step S4, when the two railcars are transporting the tie rod arch in coordination, the front and rear railcars are linked by a wireless synchronous control system, and the transport speed is controlled between 0.5m / min and 1.5m / min. Limiting and guiding devices are set on both sides of the transport path to prevent the tie rod arch from shifting laterally.

[0011] Preferably, in S1, when assembling the tie arch using the bracket method, the bracket is placed on a flat site behind the abutment with sufficient bearing capacity. Adjustable steel pads are used for the pads, the railcar tracks are laid longitudinally along the tie arch, and the track foundation is compacted and reinforced.

[0012] Preferably, in step S5, when the cable crane lifts the front end, a double safety pin is set at the connection point between the lifting cable and the lifting lug at the front arch foot of the tie arch. The lifting height is such that the front end of the tie arch is 200mm to 500mm higher than the top surface of the railcar. After the front railcar is withdrawn, the traction rope is connected to the lifting lug at the rear end of the tie arch through a steering pulley to ensure that the direction of the tension is parallel to the arch axis.

[0013] Preferably, in S7, during system conversion, the temporary supports and track vehicles are first removed, and then permanent supports and arch rib connection nodes are installed to complete the conversion of the tie arch from a temporary support state to a permanent structural system. The conversion process adopts a graded unloading method, and the unloading amount of each grade does not exceed 10% of the design load.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The construction method of the tie-arch bridge using cable crane described in this invention assembles the tie-arch as a whole on the land behind the abutment, and completes most of the high-precision welding, connection and alignment control operations on the ground in a safe and controllable manner. This greatly reduces the risks and difficulties of high-altitude and water-adjacent operations, significantly improves construction safety and component assembly quality, and effectively reduces continuous interference with navigation.

[0015] 2. The construction method for integral installation of tied arch bridges using cable cranes, as described in this invention, innovatively adopts a collaborative operation mode combining "land railcar-assisted transportation" and "asymmetric cable tower cable crane traction," achieving rapid and integrated transportation and installation of large-span tied arches from the assembly yard to the bridge site. Compared with traditional segmented hoisting and high-altitude splicing processes, this method significantly shortens the main structure erection period, improves installation efficiency, and optimizes traction mechanical performance through asymmetric cable tower design, ensuring the stability and controllability of the long-distance, large-span traction process. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the present invention; Figure 2 This is a schematic diagram of the assembled tie rod arch of the present invention; Figure 3 This is a schematic diagram of the tie rod arch moving to the cable hoisting starting point area of ​​the present invention; Figure 4 This is a schematic diagram of the cable-stayed traction tie-rod arch crossing the river according to the present invention; Figure 5 This is a schematic diagram of the installation and positioning of the tie rod arch of the present invention; Figure 6 This is the present invention. Figure 5 A top-down view; In the attached diagram: 1. Tie-rod arch; 2. Cable tower; 3. Sliding track; 4. Mooring pad; 5. Railcar; 6. Main pier; 7. Temporary support; 8. Cable crane; 9. Anchorage. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects of the invention can be achieved even without these specific details.

[0018] Please see Figures 1 to 6 This invention provides a construction method for installing a tied-arch bridge using cable hoisting, the technical solution of which is as follows: S1. On-site assembly On the approach bridge deck behind the abutment or on a leveled and compacted site, a complete tied arch 1 structure is assembled using a steel pipe scaffolding method. The assembly site must be flat and have a bearing capacity of not less than 150 kPa. Adjustable steel pads 4 are laid at the bottom of the tied arch 1 as temporary supports, and the top elevation of the pads 4 is precisely adjusted according to the design alignment of the tied arch 1. At the same time, two sliding tracks 3 are laid directly below the bottom of the tied arch 1 along its longitudinal axis. The track foundation must be compacted in layers and a concrete base is laid to ensure stability. Two large-tonnage railcars 5 are placed on the tracks. During the assembly process, the arch rib alignment, welding quality, and overall dimensions are strictly controlled, and all permanent connections are completed (except for the connection with the pier supports).

[0019] S2. Synchronously set up the cable system Cable towers 2 are installed at appropriate locations on the outer side of the abutments on both sides of the bridge. To ensure the mechanical advantage of subsequent traction operations, the cable towers 2 are configured asymmetrically: the height of the cable tower 2 far from the assembly site (downstream side) is designed to be H1, and the height of the cable tower 2 close to the assembly site (upstream side) is designed to be H2, and H2>H1. In this embodiment, H2 is about 20% higher than H1 to ensure that the angle between the subsequent traction rope and the horizontal plane is within the range of 40°~50°, thereby providing greater horizontal tension in the initial stage of traction. Two independent cable hoisting systems 8 are erected between the two cable towers 2, and their main span should be greater than the main span of the tie arch 1. The two ends of the load-bearing cables of the cable hoisting system 8 are respectively anchored to anchorages 9 set on the shore. At the same time, a temporary support 7 for temporary support of the tie arch 1 is pre-erected in front of the permanent main pier 6 of the bridge.

[0020] S3, Loading and unloading of temporary supports on tie-arch After the tie-arch 1 is assembled and inspected as a whole, jacks and other equipment are used to smoothly lower the tie-arch 1 onto the two railcars 5. Then, the hydraulic lifting systems of the two railcars 5 are started simultaneously to lift the tie-arch 1 as a whole, so that its bottom is completely separated from the pads 4 below. The lifting height is controlled at 80mm. After confirming that the railcars 5 are evenly and stably stressed, all pads 4 are removed to prepare for overall transportation.

[0021] S4, Tie-arch integral transportation Two railcars 5 work together via a wireless synchronous control system to transport the tie-arch 1 toward the riverbank at a speed of approximately 1.0 m / min along the preset sliding track 3. Limiting and guiding devices are installed on both sides of the transport path to prevent the tie-arch 1 from shifting laterally. The synchronicity of the railcars 5 and the attitude of the tie-arch 1 are continuously monitored during the transport process until the front end (arch foot) of the tie-arch 1 is transported to the area directly below the lifting area of ​​the cable crane 8 on the side near the assembly yard.

[0022] S5. Cable crane lifting and pulling across the river Front-end lifting: Operate the cable crane 8 located near the assembly yard. The hook of its lifting cable is connected to the pre-set lifting lug at the front arch foot of the tie rod arch 1 through a double safety pin. Slowly lift the lifting cable to lift the front end of the tie rod arch 1 about 300mm away from the top surface of the rear railcar 5. After confirming that the lifting point is safe, remove the front railcar 5. Crossing the river by traction: Start the traction winch of the cable crane 8 on this side, and use the traction cable to horizontally pull the front end of the tie arch 1 to move it to the opposite bank of the river; at this time, the rear end of the tie arch 1 is still supported on the railcar 5 behind it. The railcar 5 moves synchronously and in the same direction as the cable crane 8, and together undertakes the transportation task of the tie arch 1; the entire crossing process needs to be slow and smooth, and the cable force of the cable crane 8 and the alignment and position of the tie arch 1 should be monitored in real time.

[0023] S6. Positioning, Fine-tuning, and System Transition Positioning: Cable crane 8 pulls the tied arch 1 above the bridge site, aligning its two arch feet with the permanent supports above the main pier 6. At this point, the tied arch 1 is supported by cable crane 8 and the track vehicle 5 behind it. Precise Adjustment: Using the temporary support 7 pre-erected in front of the main pier 6 as auxiliary support, or directly utilizing the fine-tuning function of the cable crane 8, combined with the hydraulic jacks and total station measurement system set at the arch foot, the planar position, elevation, and axis of the tied arch 1 are precisely adjusted in three dimensions. The adjustment accuracy is controlled within: planar position ±3mm, elevation ±5mm, and axis deviation ±2mm, until it fully meets the design requirements; System Conversion: After fine-tuning, the arch foot of the tied arch 1 is connected to the permanent support and temporarily locked. Then, unloading is carried out in stages: First, the lifting cable of the cable crane 8 is lowered synchronously and slowly to gradually transfer the load to the permanent support, with each unloading amount being 10% of the design load; after the cable crane 8 is completely unloaded, the track car 5 is removed; finally, the temporary support 7 is dismantled; at this point, the tied arch 1 is completely converted from a temporary support system consisting of pad 4 + track car 5 + cable crane 8 to a complete bridge structure system supported by permanent supports, completing the final installation.

[0024] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A construction method for integrally installing a tied-arch (1) bridge using cable hoisting (8), characterized in that, Includes the following steps: S1. On-site assembly: At the selected site behind the bridge abutment, the tie arch (1) structure is assembled using the bracket method. Temporary support pads (4) are provided at the bottom of the tie arch (1), and transportation components are set at the bottom. S2. Synchronous cable system setup: Cable towers (2) are set up on the banks on both sides of the tie arch (1), and the main span of the cable crane (8) is greater than the main span of the tie arch (1); wherein, the cable towers (2) are asymmetrically configured, specifically: the height of the cable tower (2) on the side away from the assembly site of the tie arch (1) is lower than the height of the cable tower (2) on the side closer to the assembly site; S3. Loading and unloading the tie arch (1) from the temporary support: The assembled tie arch (1) is lowered onto the transport assembly, which includes a railcar (5). The tie arch (1) is lifted by two railcars (5) set at the front and rear, so that it is unloaded from the bottom pad (4). Then all pads (4) are removed. S4. Overall transportation of the tie-rod arch (1): The transportation assembly is equipped with a track, and two track cars (5) move along the track together to transport the tie-rod arch (1) to the lifting area of ​​the cable crane (8); S5. Cable crane (8) lifts and pulls across the river: using the cable system in conjunction with the tie arch (1), the front end of the tie arch (1) is lifted to the set height and the railcar (5) is withdrawn; then the tie arch (1) is pulled across the river by the cable system, while the railcar (5) behind continues to support the transport. S6. System conversion and final installation: Remove the temporary supports and track car (5), complete the system conversion of the tie arch (1) from the temporary support state to the permanent structure, and achieve final installation.

2. The construction method for installing a tied arch (1) bridge using a cable-stayed crane (8) as a whole according to claim 1, characterized in that: The transport component in S1 includes a cable tower (2) located near the assembly site with a sliding track (3), two pads (4) on the sliding track (3), and two railcars (5) on the sliding track (3). The tie rod arch (1) is temporarily placed on the two pads (4).

3. The construction method for installing a tied arch (1) bridge using a cable-stayed crane (8) as described in claim 1, characterized in that: The cable system in S2 includes two cable towers (2), each cable tower (2) has a main pier (6) in front of its opposite side, each main pier (6) has a temporary support (7), two cable gantry (8) are provided between the two cable towers (2), and two anchors (9) are provided outside each cable tower (2), and the two ends of the two cable gantry (8) are respectively connected to the corresponding anchors (9).

4. The construction method for integrally installing a tied arch (1) bridge using a cable-stayed crane (8) according to claim 1, characterized in that: In S2, when the cable crane (8) tower is asymmetrically configured, the tower height on the side away from the assembly site is 10% to 30% lower than the tower height on the side closer to the assembly site, so as to ensure that the angle between the traction rope and the ground is maintained within the range of 30° to 60° during the forward movement of the cable crane (8), thereby providing a more stable pulling force.

5. The construction method for integrally installing a tied arch (1) bridge using a cable-stayed crane (8) according to claim 1, characterized in that: In S4, when the two railcars (5) transport the tie arch (1) together, the front and rear railcars (5) are linked by a wireless synchronous control system, and the transport speed is controlled between 0.5m / min and 1.5m / min. Limiting guide devices are set on both sides of the transport path to prevent the tie arch (1) from shifting laterally.

6. The construction method for integrally installing a tied arch (1) bridge using a cable-stayed crane (8) according to claim 1, characterized in that: In S1, when the tie arch (1) is assembled by the bracket method, the bracket is arranged on a flat site behind the abutment with sufficient bearing capacity. The pad (4) is an adjustable steel pad. The track of the railcar (5) is laid longitudinally along the tie arch (1). The track foundation is compacted and reinforced.

7. The construction method for integrally installing a tied arch (1) bridge using a cable-stayed crane (8) according to claim 1, characterized in that: In S5, when the cable crane (8) lifts the front end, a double safety pin is set at the connection point between the lifting cable and the lifting lug at the front arch foot of the tie arch (1). The lifting height makes the front end of the tie arch (1) 200mm to 500mm higher than the top surface of the railcar (5). After the front railcar (5) is removed, the traction rope is connected to the rear lifting lug of the tie arch (1) through a steering pulley to ensure that the direction of the tension is parallel to the arch axis.

8. The construction method for integrally installing a tied arch (1) bridge using a cable-stayed crane (8) according to claim 1, characterized in that: In S7, during system conversion, the temporary support (7) and track car (5) are first removed, and then the permanent support and arch rib connection node are installed to complete the conversion of the tie arch (1) from the temporary support state to the permanent structural system. The conversion process adopts a graded unloading method.

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