Earthquake Residual Deformation And Damage Control For PRC Bridge Pier

If piers appeared a large residual displacement after earthquake or collapsed, as an important bearing component of bridge structures, it will cause serious threat to life safety and lead to more difficulties to post-disaster reconstruction project. Accurate assessment of residual displacement of bridge piers after earthquake and effective means to control the damage of bridge piers are effective methods to improve the seismic performance of bridges. In view of the limitations of experimental study, this paper established a bridge dynamic analysis model based on the OpenSees software platform. It is able to accurately simulate the residual displacement value of the bridge piers after earthquake. Then, the influence of the prestressed reinforcement has been further discussed. The main work contents and conclusions are as follows:1. Firstly, develop the analysis model which can effectively simulate the residual deformation of RC bridge after the earthquake. Then compare the simulation results with experimental results to ensure the accuracy of the numerical model. On this basis, dynamic analysis was carried out under the real earthquake. Discuss the influence law of residual deformation of RC piers with the unbonded prestressed strands. And also study the relationships of Residual displacement and maximum displacement, maximum stress of prestressed reinforcement and maximum drift, and other engineering design indexes. Results show that prestressing strands in the RC bridge piers can effectively reduce the residual displacement. Increasing prestressing strands is an effective method to control the damage of bridge piers after the earthquake.2. To study the seismic performance of repair piers after the earthquake, using OpenSees numerical analysis platform, establish numerical analysis model of repair bridge pier considering the damage of reinforcement. In order to verify the applicability of the model, compare the simulation results with the pseudo-static test results of five piers with circular section that appeared bending failure. Then apply the repair model to the dynamic analysis. By means of IDA, the seismic capacity of repair bridge pier and the repair pier with prestressed strands are analyzed. Results show that the ordinary repair RC bridge pier can satisfy the basic requirement, but thoroughly damage after the quake, but after earthquake, the repair bridge piers with prestressed strands still keep repairability. Once again to verify the prestressed reinforcement of RC bridge pier can control the residual displacement efficiently.3. In view of the limitations of the means of experimental study, in the present study the influence of the amount, initial stress level and position of prestressed reinforcement to the residual displacement under the action of the earthquake is not clear. Unable to provide theoretical basis for this kind of structure seismic design In this chapter, a comprehensive system of research of the vertical configuration of unbonded prestressed RC bridge pier has been made. To discuss the relationship between axial force and preloading stress, proportional relationship between Prestressed reinforcement and the longitudinal reinforcement, the strength of concrete and other parameters that effect the residual displacement of the piers under the dynamic time history. To provides some reference and certain theoretical basis for prestressed pier design. Finally, established the upper structure, pile-soil interaction analysis model, and discussed the earthquake damage of PRC bridge piers under the pile-soil interaction...