Response Of Simply Supported Beam Bridges Under Earthquake And Evaluation Of Post-disaster Bearing Capacity

The occurrence of the earthquake is often accompanied by the serious damage of the traffic system.The interruption of traffic directly affects the development of disaster relief work and brings more serious secondary disasters.The painful lesson of the earthquake disaster makes people pay more and more attention to the seismic research of bridge engineering.Combined with Shuohuang railway bridge health monitoring project,based on the earthquake investigation of typical large earthquakes and the research progress of bridge anti-seismic at home and abroad,this paper studies the structural response and bearing capacity of Railway Simple Supported Beam Bridge under earthquake.The main contents and conclusions of this study are as follows:(1)According to the typical large earthquakes occurred at home and abroad,the seismic damage of Bridges was counted and summarized,the classification of seismic damage of Bridges in the current code was explained,and three prediction methods of seismic damage of Bridges were introduced.(2)According to the relevant engineering background,the finite element model of 32 m railway reinforced concrete simply supported beam bridge is established with ANSYS software,and two comparative models of different span number and different span combination modes are established.The main loads of the bridge structure are calculated and the modal analysis of the three models is carried out.(3)Reference related to seismic code and practical bridge local geographical conditions,selection of bridge seismic design of acceleration response spectrum response spectrum analysis,the seismic response of the bridge structure,proposed the bridge structure in the earthquake vulnerability and vulnerability of components,the security of the bridge pier is calculated under the seismic action,the result shows that the strength of the pier cross-section and eccentric can satisfy the requirements of specification.(4)The earthquake damage grade of the bridge is determined by the empirical statistics method,and several possible earthquake damages of the bridge are put forward.The performance of the bridge pier under each condition is calculated and analyzed,and the bearing capacity and trafficability of the bridge after the earthquake are evaluated.The results show that the bridge cannot continue to pass when the fracture depth of the bottom section of the pier after the earthquake is more than 30 cm and the longitudinal and transverse displacement of the beam are both greater than 40 cm.