Dynamic Time History Analysis Method Research Articles

A New Method to Select Seismic Records for Time-History Analysis to Hydro-Structure

In order to make sure the structures have well seismic performance, the designer adopt dynamic time-history analysis method .But there is a problem to calculate the dynamic response of the structures which is how to find a scientific and reasonable criterion to select seismic wave records. In order to solve this problem and find a scientific and proper criterion to select seismic wave records, this paper referred to the standards ruled by the new Chinese Seismic Design Code for hydraulic structures and used the numerical analysis and scientific computation, conducted a well meticulous analysis, then put forward one way to select seismic records for time-history analysis method of hydro-structure. Except for taking the site condition, the fortified intensity, the duration into consideration, the author also give more emphasis on the fitting degree between the response spectra of seismic records with the new code to provide better fitting degree.

Study on the Impact of Lead-Rubber Bearing Parameters on Seismic Responses of Seismically Isolated Pier

Based on the finite element program SAP2000, 120 models of eight different piers with different lead-rubber bearings (LRB) are established. The seismic response analyses of piers isolated by LRB in axial direction of the bridge are carried out under the excitations of seven earthquake waves. The calculations of seismic responses of the piers with and without isolation are implemented by using dynamic time-history analysis method, and the comparison of the results is given out. Considering the isolation ratio of the moment at the bottom of pier as observation samples, the variances of the three LRB mechanical parameters are analyzed. Furthermore, the ability of the parameters of LRB to adjust the seismic response of different piers is discussed. The analysis results show that all the mechanical parameters of LRB have significant effect on the isolation ratio of the moment at the bottom of pier, and the parameters of LRB can adjust the seismic forces of the isolated piers whose height difference is less than 30 meters to be almost equal. This paper provides some valuable references for the further study of isolation design for railway bridges.