Dynamic and real-time monitoring method of prestressed tendon tension in concrete bridges and special prestressed construction system

Abstract

The invention belongs to bridge construction, and particularly relates to dynamic real-time monitoring method for concrete bridge prestressed tendon tensioning force and a special prestress construction system. The dynamic real-time monitoring method for the concrete bridge prestressed tendon tensioning force includes the steps of initializing and real-time dynamic control loading. The prestress construction system comprises at least one tensioning device, and each tensioning device comprises a hydraulic station, a reversing valve bank, a jack, an A / D data collecting module, a PLC, a central processing unit, a human-computer interface, a direct force measuring device, a hydraulic force measuring device, a prestressed tendon elongation measuring device, a friction resistance test device and a security alarm device. The double-control requirement, difficult to met in the prior art, for taking stress control as the principle thing and an elongation value as a checking item is met, the dynamic real-time monitoring method has the advantages that construction quality and safety can be effectively ensured, and problems found in the tensioning process can be solved in time.

Description

technical field [0001] The invention belongs to bridge construction, in particular to a dynamic and real-time monitoring method and a special prestressed construction system for the tension force of prestressed tendons of concrete bridges. Background technique [0002] In the construction of high-speed railways in my country, bridges occupy an absolute proportion in the length of the lines because of their good ride comfort, the line is not easy to settle, the land is saved, and the operation is safe. The prestressed concrete bridge has the characteristics of strong crack resistance, good impermeability, high rigidity, high strength, good shear resistance and fatigue resistance. Both cracking and deflection reduction are very effective, allowing bridge structures to be designed more economically, lightweight and aesthetically pleasing. [0003] With the application of prestressing technology in modern bridge construction, the quality and performance of bridges have been gre...

AI Technical Summary

Problems solved by technology

However, the previous construction methods can only check the final tensioning results. If there is a misoperation or a large deviation in the tensioning force during the tensioning process, the steel strand will slip or break, and there will be a large deviation in the elongation value at this time. , can not be detected in time through the abnormal elongation value, which may cause serious construction or personnel safety accidents such as prestressed breakage, clamp ejection, beam end crushing, etc.

Therefore, the traditional construction technology is difficult to meet the dual control requirements of "focusing on stress control and elongation as a check".

[0007]At the same time, the main problems in the control mode and process of the previous "smart tension" equipment are as follows: First, the hardware uses the hydraulic pressure collected by a single sensor to replace the measured tension Or collect the actual measured tension to reach the program preset target value as the only condition for the termination of the tension loading action. The sensor has a single detection point and cannot be calibrated by itself. Once the sensor has a data jump or fails, the tensioning construction of the equipment will have serious problems; The second is that in terms of the process, the tension and elongation values ​​are manually input, and it is impossible to calculate whether it is normal by itself. Input errors will also affect the results of the tensioning construction; at the same time, all tensioning data can only be calculated by the system after the tensioning is completed. It is impossible to make up for the problems found; the third is that steel strands may slip or break during the tensioning construction, which makes the corresponding relationship between the current tension force and elongation of the steel strands abnormal, and the abnormal situation cannot be discovered in time. Continued tensioning and loading can cause steel strands to break, anchor holes to be partially crushed, or insufficient prestress to cause vertical cracks in the beam body, affecting structural safety and durability, and causing operational safety hazards

Images