Seismic Response Analysis Of Water-soil-bridge Systems

The influence of hydrodynamic on deep-water bridges under seismic action can not be neglected.The integral models of water-structure and water-soil-structure were built respectively based on dynamic artificial boundary and fluid-structure interaction method,and compared with the models based on simplified Morison equation and radiation wave theory under different working conditions.A 3D finite element analysis model was built on the basis of a certain sea-crossing bridge.Dynamic response analysis and parameter analysis of the deep-water bridge were carried out.The main work of this paper and the corresponding results are as follows:(1)The integral models of water-piers,water-single pile and water-multi-piles were built based on the acoustic fluid model,compared with models based on Morison equation method and radiation wave theory,and analyzed the different dynamic characteristics among these models.The dynamic time-history analysis of three models were carried out,and the comparison of results were made.For the large-size structures such as piers,the results obtained by the two simulation methods of fluid-solid interaction and radiation wave theory are very close;For small structures such as piles,there is little difference among the above three simulation methods.The parameters of water depth of single pile were also analyzed to clarify the influence of the factors on structures.(2)Based on the viscous-spring artificial boundary element and the seismic wave input method,the modals of water-soil—single pile under single layer soil condition were built,and the difference between these two methods in the case of considering the interaction between soil and structure was studied,the difference among these two modals and the modal under anhydrous conditions was also studied;the modals of water—soil—monopile based on two different methods which are acoustic fluid element and the combination of beam element and additional mass method were built under multi-layer soil condition,the feasibility of these two simulation methods was analyzed through the comparison.And the comparison among these two modals and the modal under anhydrous conditions were made.(3)Taking a continuous rigid frame bridge as the background,the dynamic response of water-soil-bridge system was studied,the amplitude and distribution of internal force of bridge were analyzed and compared with bridges without considering the effect of hydrodynamic.And the influence law of hydrodynamic on the dynamic response of deep-water bridge was studied.