Research On The Prestressed Tensioning Technology For Cantilever Casting Continuous Rigid Frame Bridge

The quality of long-span continuous rigid frame bridge during the period of prestressed tension plays a decisive role on the durability and safety during the bridge service period. However, the current specification for the construction process of the pre stress is not clear, especially for the multi-top speed tension. Therefore, the phenomenon of span deflection caused by prestressing loss which caused by improper order is relatively common.This paper effectively in the process of tensioning prestress reserve problems, intends to combine in the Yao Yan bridge engineering of Zhao Ma high-speed. By using a combination of research method based on numerical simulation technology and laboratory test and field test, given the more accurate construction method of prestressed structural model, synchronization of multi-top prestressed tension order, puting forward the principle of construction standardization technology of prestressed tensioning. By analyzing the prestress effect of the structure under different tension, giving the rapid construction standardization technology of the prestressed concrete of the continuous rigid frame bridge.The main contents and conclusions are as follows:Firstly, based on the theory of the whole process of multi-stage construction, the indoor tension test of prestressed simply supported beam is carried out. The numerical model is used to simulate the tension process of the experimental beam. By comparing the experimental data to modify the model parameters, the method of constructing the model with high accuracy is presented.Secondly, using the validated simulation method to establish a continuous rigid frame bridge cantilever construction the construction segmental prestressed tensioning numerical model of the process. Studying on the prestress effect of the longitudinal prestressing bundle in symmetric tension and asymmetric tension, and the principle of the priority is to be drawn near the center line.At last, according to different tensioning order to carry out the numerical tests. With the comparative study on the 0 pillar top piece,1 piece of the deformation and stress, gives more top synchronous tensioning of the optimal construction sequence.The research is helpful to accurately simulate the construction of the prestress tension, and to analyze the construction of the effective prestress in different tension sequence. At the same time, providing the reference for the rapid construction standardization technology of the prestressed concrete of the continuous rigid frame bridge.