Seismic Response Analysis Of The Continuous Rigid Frame Bridges

In recent years, earthquake disaster frequently occurred all over the world, which brought great damage to the safety of life and property for people. And bridges are life line engineering, once destroyed, the extent of secondary disasters will increase, leading to more serious life and property and economic loss. Prestressed concrete continuous rigid frame bridge is widely used type of bridges, studying the seismic response of which is important.Firstly, this paper introduces the bridge damage, the characteristics of continuous rigid frame bridge and the actuality of seismic response study of high pier and longer span continuous rigid frame bridge. Further, it elaborated the basic theory of seismic response analysis and expounded response spectrum analysis method and dynamic time history analysis method in detail.On the basis, by taking new jing kou Jialing River Bridge as a project example, dynamic response orderliness was studied. The main contents and conclusions include:(1) The pile foundation work and portal rigid frame finite element models are established considering the frequence and period of the bridge. Portal rigid frame model ismore flexible than pile foundation work model.(2)Combining the horizontal and vertical, the seismic response of the two models were analyzed by response spectrum to determine that the pile foundation is more aseismatic.(3) The pile foundation work model was analyzed by dynamic time-history analysis methods and compared with the result under the response of spectrum. On the whole, the response spectrum results are more conservative than time-history analysis. But we should adopt the larger result when design.(4)The seismic responses of the continuous rigid frame bridge is numerically simulated considering traveling-wave effect. The internal force and the displacement of the bridge decreases with the difference of the speed of the earthquake wave. The results show that it is not sure that the coincident earthquake excitation is the most adverse circumstances. Therefore, the design should be based on actual site conditions and select the appropriate seismic wave velocity for analysis. It is expected to give some references for practical seismic design of similar bridges.