CN-117536104-B - Construction method of suspended single-cable-plane cable-stayed steel bridge

Abstract

The invention discloses a construction method of a suspended single-cable-plane cable-stayed steel bridge, which comprises the following steps of firstly, three-dimensional modeling of the cable-stayed bridge, secondly, temporary support system construction, thirdly, overall stress analysis of the cable-stayed bridge, fourthly, pedestrian comfort vibration reduction analysis of the cable-stayed bridge, and fifthly, installation and tensioning of a cable-stayed cable. Aiming at the problems that the single cable-plane cable-stayed bridge structure of a suspension system is small in soft rigidity, the pedestrian comfort level does not meet the requirements and the small cable force is asymmetric and collaborative in tensioning, the finite element simulation analysis technology is utilized to systematically analyze the dynamic characteristics and the sensitive frequency range under different walking working conditions under different load conditions, and the vertical and horizontal TMD damping devices are arranged to ensure that the pedestrian comfort reaches the optimal level and ensure the safety and the comfort of the bridge.

Inventors

• ZHANG HAICHUAN
• GONG JIAN
• JIA MIN
• JIANG YOURONG
• FU HANG
• WANG YONGDONG
• ZHANG DALIN
• SONG QINGXING
• ZHAO JIABIN
• ZENG QIANG

Assignees

• 中国五冶集团有限公司

Dates

Publication Date

20260508

Application Date

20231027

Claims (6)

1. 1. The construction method of the suspended single-cable-plane cable-stayed steel bridge is characterized by comprising the following steps of: Step one, three-dimensional modeling of a cable-stayed bridge; step two, constructing a temporary support system; thirdly, analyzing the overall stress of the cable-stayed bridge; Step four, analyzing comfortable vibration reduction of people on the cable-stayed bridge; step five, installing and tensioning stay cables; In the first step, when the cable-stayed bridge is modeled in three dimensions, three-dimensional coordinate parameters in a design drawing are led into CAD and are fitted by curves to form a line model, and then the line model is led into Rhino for detail deepening; when the drawing is processed and installed, a CAD model is uniformly derived from the Rhino model, so that the consistency of control point data is ensured, in the construction process, retesting is carried out on processing and installing entities, the data is returned to the CAD model for three-dimensional comparison, adjustment is carried out according to the comparison result, and the installation precision of the curved light and thin special-shaped steel box girder is ensured; In the fourth step, when the pedestrian comfort vibration reduction analysis is carried out on the cable-stayed bridge, a 3D refined finite element model is established through MIDASCIVIL, and the system analysis is carried out on the induced vibration of the bridge; According to the dynamic characteristic result, the sensitivity range of the vertical vibration frequency is a first order to a third order, the sensitivity range of the horizontal vibration frequency is a second order to a fourth order, comfort degree analysis is carried out according to the sensitivity modal frequencies of each order which are judged according to EN03-2007 and CJJ69-201X standards respectively, and according to the comfort degree analysis result, the damping of a cable-stayed bridge structure is increased by adopting a TMD damping device to improve the vibration comfort degree of a person, and 13 sets of TMD final debugging is reserved; in the fifth step, when the stay cable is installed and stretched, the method comprises the following steps: Step 1, establishing a three-dimensional finite element model; step2, simulation analysis of the tensioning process; Step 3, stretching and installing a guy cable; step 4, stretching and monitoring the inhaul cable; step 5, constant load and cable adjustment in the second period; step6, bridge monitoring and TMD frequency modulation; In the step 1, when a three-dimensional finite element model is established, a MIDAS/CIVIL is adopted to analyze a cable tower, a main beam, a stay cable and a temporary support, the geometric shape reflects the final line shape adopted by the bridge, and the technical parameters of structural rigidity, section characteristics, structural quality and non-structural quality are accurately reflected so as to reasonably analyze the actual mechanical behavior of a structural system; the constraint condition in the process is that the cable tower is fixedly connected by adopting a tower beam, and a beam end pier column is supported by a one-way support, and a C beam Duan Fuchu pier is supported by a one-way movable support; The load is applied in the process, namely, the constant load of a main beam is applied, after the weight of a diaphragm plate is calculated in sections in a beam unit model, uniform load is applied to different beam sections, besides the diaphragm plate, the beam sections are preloaded with TMD vibration reduction devices when leaving the factory, the weight of the TMD vibration reduction devices is loaded to corresponding nodes by adopting node load, C20 concrete is poured into the beam ends to carry out weight compaction, the model applies weight load, and the constant load in the second period comprises a drainage structure, railing handrails and bridge deck pavement, the weight concentration of guardrails is calculated according to the linear meter, the average thickness of a pavement layer is 55mm, and the variable and sectional calculation loading of different beams Duan Kuandu is carried out; In the step 2, during the simulation analysis of the tensioning process, bridge forming force optimization is firstly carried out, the ideal bridge forming linear machining is adopted without considering the pre-camber, the main beam is formed by hoisting and installing on a bracket and finally welding, and the main beam in a simply supported state has initial deflection and is converted into a continuous beam after welding; the initial state of the cable-stayed tower is an ideal vertical state, the cable-stayed tower is simulated to be tensioned, an ideal bridge-forming state is achieved after all secondary constant load is applied, the corresponding cable force is the target bridge-forming cable force, then the cable-stayed sequence simulation optimization is carried out, the cable tensioning is carried out in two steps, the first step is symmetrically tensioned to 100% of a design value by adopting a grading loading mode after the cable-stayed tower is hung, the loading is carried out to 30%, 80% and 100% of three-level loading, the loading is stopped for 5 minutes after each level of loading tensioning is finished and used for monitoring data acquisition and simulation analysis, the second step is carried out to adjust the cable force to the design value according to the monitoring simulation analysis result after the bridge deck engineering, the lamplight and the accessory facilities are all finished, the single cable tower cable tensioning sequence is carried out from bottom to top, a pair of stay cables are symmetrically tensioned each time, the second pair of stay cables are tensioned from bottom to top, and finally the first pair of cables are tensioned, the tension is continued when the designed bridge cable force value is not reached according to the simulation analysis part, and the tension is not reached, and the tension is regulated when part of the cable force exceeds the designed bridge cable force value.
2. 2. The construction method of a suspended single-cable-plane cable-stayed steel bridge according to claim 1, wherein in the second step, when the temporary bracket system is constructed, the supporting frame is designed as a circular pipe supporting frame, the material Q235B is adopted, and the upright post is a circular pipe phi 325 10, The horizontal support and the inclined support adopt round tubes phi 150 10, The size of the supporting frame is 2.5m 3M, standard sections of the support frame are sections with three length specifications of 1m, 3m and 4m, the joint connection design in the support frame sections adopts flange connection, the support frame is convenient to mount and dismount, semi-penetration welding seams are adopted between the horizontal support and the upright posts, the penetration depth is 0.8t, the welding seam size is not less than 0.75t and not less than 8mm, the welding seams of all the joints connected by the inclined support are fillet welding seams in three stages, the welding seam size is not less than 8mm, column foot stiffening plates are arranged at column foot and flange connection positions, the plate thickness is 12mm, and the size is 150 200 16mm; The upper part of the temporary support is connected with a customizing tool which comprises a conversion beam, an elevation bench and a limiting block, wherein the specification of the conversion beam is not less than HM294 multiplied by 200 multiplied by 8 multiplied by 12, a vertical supporting rod of the elevation bench is selected from round pipes P159 multiplied by 8, a connecting cross rod and an inclined rod are selected from round pipes P140 multiplied by 8, the limiting block is spliced by a steel plate, and a plumb of a limiting surface is adopted; The lower part of the temporary support is provided with an enlarged concrete foundation, the single support of the main bridge is 3.5mX4.0mX0.5m, the main bridge supports are welded and connected by adopting embedded parts with 700X 20mm, the concrete used for enlarging the concrete foundation is C30, the bottom is provided with a single-layer bidirectional C16@150 reinforcing steel bar net sheet, the lower part of the support is provided with a C20 concrete cushion layer with the thickness of 10cm, long-side splicing type and short-side splicing type are arranged according to different bridge widths and field geographic environments, the foundation size is 6.7mX4.0mX0.5m for enlarging the concrete foundation by adopting the long-side splicing double-row supports, and the foundation size is 7.7mX3.5mX0.5m for adopting the short-side splicing double-row supports.
3. 3. The construction method of the suspended single-cable-plane cable-stayed steel bridge is characterized by comprising the steps of positioning a pay-off bracket to enlarge a concrete foundation area according to the plane position of a temporary bracket when the temporary bracket system is built, carrying out bracket expansion concrete foundation construction according to a geological survey report and on-site practical conditions, excavating a powdery clay layer with a bearing capacity characteristic value of 160Kpa as a bearing layer, hoisting a standard section of the bracket, firmly welding the bottom of the standard section with an embedded plate, enabling each side of the welding seam to be not smaller than 200mm, enabling the standard section to be connected through flange bolts, facilitating later disassembly, manufacturing a custom fixture, deriving three-dimensional coordinates of a supporting point of the bracket according to a three-dimensional model, positioning an elevation bench and a vertical rod position on a conversion beam through plane coordinate data, determining the lengths of the vertical rod and the inclined strut through elevation data, manufacturing a single-side limiting block of a main bridge in a similar way, and welding the single-side limiting block of the main bridge on the conversion beam, and finally integrally hoisting the fixture, and carrying out actual measurement and fine tuning the elevation bench before hoisting the main bridge.
4. 4. The construction method of the suspended single-cable-plane cable-stayed steel bridge according to claim 1, wherein in the third step, numerical simulation and analysis are carried out after the whole cable-stayed bridge is modeled by utilizing finite element analysis software midas so as to fully understand the stress distribution condition of a main bridge special-shaped steel box girder in the construction process of a temporary bracket, in order to ensure the line shape of the cable-stayed bridge, the cable force value of the cable is determined through simulation so as to ensure that the line shape of the closed and unloaded main bridge meets the design requirement, the simulation calculation and analysis of the construction stage are carried out by comparing design parameters so as to obtain the corresponding pre-camber of the cable-stayed bridge, the vertical die elevation of the bridge construction stage is determined, the analysis of the previous stage is carried out according to the measured elevation, the line shape and the stress of the next stage are determined so as to determine the vertical die elevation, the line shape of the cable-stayed bridge in the bridge formation state can meet the normal use requirement, the monitoring and the acquisition of data of the cable-stayed bridge are ensured by the construction stage after the bridge is formed, the line shape is smooth, the construction error and the construction work load is reduced, and the cable-stayed bridge is ensured to be formed.
5. 5. The construction method of the suspended single-cable-plane cable-stayed steel bridge according to claim 1, wherein in the step 3, when the cable is unfolded and installed, the automobile crane, the climbing vehicle and the chain block are mutually matched, the crane is responsible for providing vertical force, the chain block is responsible for providing horizontal force, the climbing vehicle is responsible for providing an overhead working platform, and the construction method comprises the following steps: step a, hoisting a cable tray to a bridge deck, and matching an automobile crane with manual cable spreading; Step b, hoisting the fixed end of the rope body to be close to the rope tower; Step c, installing a fixed stay rope by matching the crane with the ascending vehicle; step d, installing a inhaul cable adjusting end by matching the crane with the chain block; step e, repeating the step a, the step b, the step c and the step d to finish the installation of all the guy cable hanging ropes; in the step 4, when the inhaul cable is tensioned and monitored, the whole process is tensioned according to the on-site real-time monitoring data as a guiding basis by the on-site tensioning, and the method comprises the following steps: step (a), arranging sensors and monitoring points in a full bridge manner; Step (b), installing a tensioning tool cable and a jack; step (c), loading the inhaul cable according to 30%, 80% and 100% three stages, and synchronously monitoring; Step (d), carrying out system monitoring on stress strain values and cable force values of a cable tower and a main bridge on the cable at each tensioning time of 2-3; Step (e), analyzing according to the monitoring data, and guiding the tension of the tensioned inhaul cable to adjust; step (f), repeating the step (a), the step (b), the step (c), the step (d) and the step (e) to complete stretching of the whole inhaul cable; and (g) monitoring the full bridge, and guiding the stretching of the next cable tower inhaul cable.
6. 6. The construction method of the suspended single-cable-plane cable-stayed steel bridge according to claim 1, wherein in the step 5, when the secondary constant load and cable adjustment are performed, after the secondary bridge deck system comprising a bridge deck, a railing and a handrail is constructed, the cable force of the full bridge cable is adjusted to the designed cable force according to the actually measured cable force value, the cable with larger gap between the actually measured value and the designed cable force value is firstly adjusted, then the cable with larger gap between the actually measured value and the designed cable force value is sequentially adjusted from large to small, the cable force value of the cable tower is monitored in real time during adjustment, and the adjustment is performed repeatedly according to the monitoring result, so that the deviation between the full bridge cable force value and the designed cable force value is finally within the designed allowable range; In the step6, when bridge formation monitoring and TMD frequency modulation are performed, after bridge deck system construction is completed and a guy cable is finally tuned, the full bridge frequency is uniformly measured, and the method comprises the following steps: step (1), completing bridge deck construction, and adjusting cables of a full-bridge inhaul cable; Step (2), arranging a sensor in a sensitive area; step (3), pedestrian bridge acceleration response under environmental excitation and impact load; step (4), judging the dynamic characteristics of the pedestrian bridge by FFT or PSD spectrum; Step (5), adjusting TMD frequency; and (6) repeating the step (3), the step (4) and the step (5) until the TMD self-oscillation frequency is consistent with the bridge self-oscillation frequency.

Description

Construction method of suspended single-cable-plane cable-stayed steel bridge Technical Field The invention belongs to the technical field of bridge construction, and particularly relates to a construction method of a suspended single-cable-plane cable-stayed steel bridge. Background The suspension system cable-stayed bridge has excellent landscape effect, but the system has light and soft structure and small rigidity, has poorer walking vibration body feeling compared with the conventional common pedestrian bridge, and causes panic to pedestrians psychologically when the pedestrian vibration exceeds the limit of human comfort. In order to achieve both the light feel of the bridge and the comfort of people, how to make the comfort of the bridge meet the comfort requirement of walking is a great difficulty. The action mechanism of each stay cable is equivalent to prestress, the whole structure stress is realized by tensioning each stay cable in the cable-stayed bridge structure to reach a certain cable force value, the whole bridge cable force is generated by sequentially tensioning each cable in the actual construction process, the tensioning of each cable influences the stress of the whole cable-stayed bridge, and the stay cable tensioned in the construction of the next stage also influences the cable force value of the stay cable which is already tensioned in the construction of the previous stage. The cable force is divided into two parts, namely a bridge forming cable force, namely a cable force distribution of the cable-stayed bridge after the construction of the cable-stayed bridge is completed, so that the stress of the cable-stayed bridge is reasonable, namely a reasonable bridge forming state cable force, and the bridge forming cable force is a construction cable force, namely a value of how much each cable is Zhang Ladao different in the staged construction process of the whole cable-stayed bridge, so that the bridge forming cable force after the whole construction is completed can be ensured to be a cable force value in the reasonable bridge forming state expected at the beginning of the design, and the construction cable force is reasonable. Thus, how to reasonably determine the initial reasonable bridge-forming state cable force value and the cable force value required to stretch each cable in the construction stage have become key in the construction of the cable-stayed bridge. If the cable force cannot be controlled due to the manufacturing and assembling errors of the main beam, the deviation of the cable force is sacrificed to meet the linear requirement and realize the elevation control. In the construction process, the cable force and the tensioning sequence must be strictly controlled, and the use safety of the stay cable is better ensured, so that the method has great significance for the overall construction control. The cable-stayed landscape bridge of the suspension system is designed with smaller cable force value and high tensioning precision, and meanwhile, the cable towers are asymmetrically arranged and need to be asymmetrically tensioned. Different tensioning sequences can cause great differences in bridge line types, so that the design of the construction method of the suspended single-cable-plane cable-stayed steel bridge is used for determining reasonable bridge forming force and tensioning sequences, and the technical problem to be solved by the person skilled in the art is urgent. Disclosure of Invention The invention aims to provide a construction method of a suspended single-cable-plane cable-stayed steel bridge, which aims to at least solve the technical problems. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a construction method of a suspended single-cable-plane cable-stayed steel bridge comprises the following steps of firstly, three-dimensional modeling of the cable-stayed bridge, secondly, construction of a temporary support system, thirdly, overall stress analysis of the cable-stayed bridge, fourthly, comfortable vibration reduction analysis of the cable-stayed bridge in a pedestrian manner, and fifthly, installation and tensioning of a cable-stayed cable. In the first step, three-dimensional coordinate parameters in a design drawing are led into CAD and curve fitting is used to form a line model, the line model is led into Rhino to deepen details, a CAD model is led out of the Rhino model in a unified mode during drawing processing and installation, control point data are consistent, retesting is carried out on processing and installation entities in the construction process, the data are returned to the CAD model for three-dimensional comparison, adjustment is carried out according to comparison results, and the installation accuracy of the light and thin special-shaped steel box girder with the curved surface is guaranteed. In the second step, when the temporary support system is built, the support frame is