Stay cable force and girder line shape cooperative double-control method

Abstract

The invention discloses a cooperative double-control method for stay cable force and main beam line shape, which comprises the following steps of: mounting a cable force sensor on a stay cable to measure the cable force in real time, mounting an elevation dynamic accurate measuring instrument on a main beam to measure the elevation in real time, and establishing communication connection among the cable force sensor, the elevation dynamic accurate measuring instrument and an intelligent tension system control center; and the control center comprehensively analyzes and processes according to the tensioning force of the system, the actually measured cable force and the elevation condition and controls the action of the tensioning equipment, so that the tensioning and supplementary tensioning work of the stay cable is completed, the cooperative control of the cable force and the line shape is realized, and the construction precision and the construction efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of prestress, and particularly relates to a method for coordinated dual control of stay cable force and main girder alignment. Background Art

[0002] In the tensioning of parallel wire stay cables of cable-stayed bridges, a hydraulic pump station is usually used to drive a jack for tensioning. During the tensioning process, a pressure gauge or pressure sensor on the tensioning equipment is used to monitor the cable force, and a total station is used to monitor the alignment. During construction, the stay cable is first tensioned. When the pressure reaches the stage design value, the nut is manually tightened to lock the tensile force, and then the elevation of the main girder is manually measured using a total station to determine whether the bridge alignment meets the stage requirements. After multiple tensionings and measurements like this, until the main girder reaches the design elevation. This method has the following deficiencies: 1. After tensioning to the set force, the nut is manually tightened to lock the tensile force, and the stress is transferred from the jack to the anchor head. During this process, some stress may be lost, that is, the actual cable force is inconsistent with the tensile force. Especially when the friction of the stay cable is very large due to installation or other factors, the tensile force cannot accurately reflect the actual cable force, and even when the tensile force has far exceeded the design value, the main girder still has not reached the design elevation; 2. Using a total station for alignment monitoring requires a large number of measurement and recording personnel, with high labor costs and low efficiency; it cannot monitor in real time all day long, the data is discontinuous and lagging, and it cannot provide real-time guiding parameters for construction; it is greatly affected by visibility, working environment and climate factors, and it is particularly difficult to measure under working conditions such as harsh environments, rainy and foggy weather, and at night; 3. It is difficult to organically integrate measurement and control, and it is impossible to realize the integration of construction monitoring and control of stay cables, resulting in high construction safety hazards. Summary of the Invention

[0003] The present invention discloses a method for coordinated dual control of stay cable force and main girder alignment. By installing a cable force sensor on the stay cable to measure the cable force in real time, and installing an elevation dynamic precise measuring instrument on the main girder to measure the elevation in real time, and establishing a communication connection between the cable force sensor, the elevation dynamic precise measuring instrument and the control center of the intelligent tensioning system, the control center comprehensively analyzes and processes according to the system tensile force, the measured cable force and the elevation situation, and controls the actions of the tensioning equipment, realizing the coordinated control of the cable force and the alignment, and improving the construction accuracy, construction efficiency and construction safety.

[0004] The solution of the present invention is: a method for coordinated dual control of stay cable force and main girder alignment, including: Step 1. Equipment calibration: Calibrate the intelligent tensioning system in combination with the cable force sensor to obtain the calibration equation between the system tensile force and the force measured by the cable force sensor, and input it into the control center; Step 2. Equipment installation: Install a cable force sensor on the stay cable to be tensioned, and install an elevation dynamic precise measuring instrument on the main girder; install an intelligent tensioning system; Step 3. Parameter setting: including: the designed tensile force F 设 , the designed elevation of the main girder H 设 , the system tensile force F 张 and the maximum allowable difference f between the cable force F 索 of the stay cable measured by the cable force sensor; Step 4. Tensioning: During the tensioning process, the cable force sensor continuously collects the cable force F 索 of the stay cable and transmits it to the control center of the tensioning system; the elevation dynamic precise measuring instrument continuously collects the elevation of the main girder and transmits it to the control center of the tensioning system; at the same time, the control center continuously monitors the tensile force F 张 of the tensioning system, and then the control center controls the cable force and the alignment based on the monitored data, with the elevation of the main girder as the main factor and the cable force of the stay cable as the auxiliary factor; Step 5. Supplementary tensioning: After the locking nut completes the system conversion, the cable force sensor continuously measures the cable force, and the elevation dynamic precise measuring instrument continuously measures the elevation. When there is a loss of the cable force of the stay cable and the elevation of the main girder, and it cannot meet the design requirements, the system automatically starts to perform supplementary tensioning until the design elevation requirements are met.

[0005] Furthermore, the following control strategy is adopted in the said Step 4: (1) When the elevation of the main girder, F 张 and F 索 have not reached the design values, if the deviation between F 张 and F 索 is within a reasonable range, that is, F 张 -F 索 ≤f, it indicates that the tensioning is normal and continue to tension; (2) When the elevation of the main girder, F 张 and F 索 have not reached the design values, if the deviation between F 张 and F 索 is too large, that is, F 张 -F 索 >f, the system automatically stops and maintains pressure, checks the reasons. If it is caused by an increase in friction resistance due to installation problems, continue to tension after handling; if it is caused by the communication lag of the cable force sensor, wait until the cable force sensor is stable and reaches F 张 -F 索 ≤f and then continue to tension; (3) When any one of F 张 or F 索 has exceeded the designed tensile force F 设 , but the elevation of the main girder fails to reach the design value, the system automatically stops, checks the reasons, and continues to tension until the designed elevation of the main girder is reached, and the locking nut completes the system conversion; When the elevation of the main girder reaches the designed elevation H of the main girder 设 The system will automatically stop and lock the nuts to complete the system conversion regardless of whether the system tension and the cable force of the stay cables reach the designed values

[0006] The beneficial effects of the present invention are as follows: By real-time monitoring the tensile force of the intelligent tensioning system, the real-time cable force of the stay cables and the real-time elevation of the main girder, the tensile force measured by the intelligent tensioning system and the force measured by the cable force sensor are mutually verified. In case of excessive deviation, timely intervention and treatment are carried out to solve the problem that the tensile force cannot accurately reflect the actual cable force. At the same time, the elevation measurement and control are organically combined to realize the integration of construction supervision and control of stay cables, ensure the bridge alignment and improve the construction safety BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is the control flow chart of the present invention

[0008] Figure 2 The equipment installation layout diagram of the present invention

[0009] Figure 3 is Figure 2 The enlarged view of part - A

[0010] Figure 4 is Figure 2 The partial enlarged view

[0011] Figure 5 It is the construction schematic diagram of the present invention

[0012] In the figure: 1 - main tower, 2 - intelligent tensioning system, 3 - cable force sensor, 4 - main girder, 5 - elevation dynamic precise measuring instrument, 6 - lower anchor, 7 - stay cable, 8 - tension rod, 9 - anchor ring, 10 - jack, 11 - anchor cup, 12 - support cylinder, 13 - anchor plate, 14 - nut, 15 - connecting cylinder DETAILED DESCRIPTION OF THE INVENTION

[0013] A method for collaborative dual - control of stay - cable force and main - girder alignment is implemented based on the device as shown in Figure 1 , 2 . It includes: an intelligent tensioning system 2 installed on the main tower 1, a cable force sensor 3 installed on the stay cable 7, and an elevation dynamic precise measuring instrument 5 installed on the main girder 4. The cable force sensor 3 and the elevation dynamic precise measuring instrument 5 are both connected to the control center of the intelligent tensioning system 2 through a network, and can transmit the collected data to the control center in real time

[0014] When implementing the present invention, before installing the equipment, the intelligent tensioning system and the cable force sensor are calibrated together to obtain the calibration equation between the system tensile force and the force measured by the sensor, and the equation is input into the control center. During construction, as shown in Figure 1 , 2Install the equipment as shown and set parameters in the control center, including: the designed tensile force F 设 , the designed elevation H of the main girder 设 , the system tensile force F 张 , and the maximum allowable difference f between the measured cable force F by the cable force sensor and the designed cable force F 索 . Then start the system for tensioning.

[0015] During the tensioning process, the cable force sensor 3 continuously collects the cable force F of the inclined stay cable 8 and transmits it to the control center of the tensioning control system 2; the elevation dynamic precise measuring instrument 5 continuously collects the elevation of the main girder 4 and transmits it to the control center; at the same time, the control center controls the tensile force of the tensioning system 2 and transmits it to F 索 ; according to the monitoring data, with the elevation of the main girder as the main and the cable force of the inclined stay cable as the auxiliary, control the cable force and the alignment, including: 张 (1) When the elevation of the main girder, F and F 张 and F 索 have not reached the designed values, if the deviation between F 张 and F 索 is within a reasonable range, that is, F 张 - F 索 ≤ f, it means the tensioning is normal and continue to tension; (2) When the elevation of the main girder, F 张 and F 索 have not reached the designed values, if the deviation between F 张 and F 索 is too large, that is, F 张 - F 索 > f, the intelligent tensioning system 2 automatically stops and maintains pressure, and the construction personnel check the reasons. If it is caused by an increase in friction due to installation problems, continue to tension after handling; if it is caused by the communication lag of the cable force sensor 3, wait until the cable force sensor 3 is stable and F 张 - F 索 ≤ f and then continue to tension; (3) When F 张 or F 索 exceeds the designed tensile force F 设 , but the elevation of the main girder 4 fails to reach the designed value, the intelligent tensioning system 2 automatically stops, checks the reasons, and continues to tension after handling until the designed elevation of the main girder is reached, and then locks the nut 14 to complete the system conversion; (4) When the elevation of the main girder reaches the designed elevation H of the main girder 设 , regardless of whether F 张 and F 索 reach the designed value F 设 , the intelligent tensioning system 2 automatically stops, and locks the nut 14 to complete the system conversion; (5)Supplementary tensioning: After the system conversion is completed by the locking nut 14, the cable force sensor 3 continuously measures the cable force of the stay cable, and the elevation dynamic precise measuring instrument 5 continuously measures the elevation of the main girder. When there is a loss of stay cable force and main girder elevation and it cannot meet the design requirements, the system automatically starts supplementary tensioning until the design elevation requirements are met.

[0016] Please refer to Figure 5 , which is an example of the construction of the present invention using four stay cables 7.

Claims

1. A method for coordinated dual control of the cable force and main beam line shape, characterized in that: The steps include: Step 1: Equipment calibration: calibrate the intelligent tensioning system and the cable force sensor, obtain the calibration equation of the system tension force and the cable force sensor measurement force, and enter it into the control center; Step 2: Equipment installation: Install cable force sensors on the inclined cables to be tensioned, and install dynamic elevation precision measuring instruments on the main beams; Install intelligent tensioning system; Step 3: Parameter setting: including: design tension F 设 , Main beam design elevation H 设 、System tension F 张 The cable force F measured by the cable force sensor 索 The maximum allowable difference f; Step 4: Tensioning: During the tensioning process, the cable force sensor collects the cable force F in real time. 索 The height of the main beam is collected by the dynamic precision measuring instrument and transmitted to the control center of the tensioning system in real time. At the same time, the control center monitors the tensioning force F of the tensioning system in real time. 张 , and then the control center controls the cable force and alignment based on the monitoring data, mainly based on the main beam elevation and supplemented by the cable force of the inclined cable; Step 5: Supplementary tensioning: After the locking nut completes the system conversion, the cable tension sensor continues to measure the cable tension, and the elevation dynamic precision measuring instrument continues to measure the elevation. When the cable tension of the inclined cable and the elevation of the main beam are lost and cannot meet the design requirements, the system automatically starts to supplement the tensioning until the design elevation requirements are met.

2. A method for coordinated dual control of the cable force and main beam line shape according to claim 1, characterized in that: The step 4 adopts the following control strategy: (1) At the main beam elevation, F 张 and F 索 When both fail to reach the design value, such as F 张 and F 索 The deviation is within a reasonable range, that is, F 张 -F 索 ≤f, indicating that the tension is normal, and the tension continues; (2) At the main beam elevation, F 张 and F 索 When both fail to reach the design value, such as F 张 and F 索 The deviation is too large, that is, F 张 -F 索 >f, the system automatically stops to maintain pressure, and the cause is checked. If it is caused by increased friction due to installation problems, continue tensioning after processing; if it is caused by delayed communication of the cable tension sensor, wait until the cable tension sensor is stable and reaches F 张 -F 索 Continue tensioning after ≤f; (3) When F 张 or F 索 Any of the above has exceeded the design tension F 设 , but the main beam elevation does not reach the design value, the system automatically stops, checks the cause, and continues to tension after processing until the main beam reaches the design elevation, and the locking nut completes the system conversion; (4) When the main beam elevation reaches the main beam design elevation H 设 Regardless of whether the system tension and cable force reach the design value, the machine will automatically stop and the locking nut will complete the system conversion.

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