SV波斜入射不同自由场构建方法下水电站地面厂房地震响应研究

针对目前近断层地震动少有考虑斜入射以及存在不同自由场构建方法的问题,研究了不同自由场构建方法的精度及其对水电站地面厂房地震响应的影响.将总波场分解为内行场和外行场,基于波场叠加原理分析了地基各边界面上的3种自由场,推导了与各边界面自由场对应的等效节点荷载计算公式,并结合边界条件实现了平面SV波斜入射输入.分析了3种斜入...

Seismic response of ground powerhouse of hydropower station based on different free field construction methods with oblique incidence of SV wave

Aiming at problems of oblique incidence being seldom considered in near-fault ground motion input and existing different free-field construction methods,the accuracy of different free-field construction methods and their influences on seismic response of ground hydropower house were studied.Firstly,the total wave field was decomposed into ingoing and outgoing fields.3 kinds of free fields on each foundation border surface were analyzed based on the principle of wave field superposition.The equivalent nodal load formula corresponding to each border surface free field was derived,and the oblique incidence input of plane SV wave was realized combining with boundary conditions.Free-field of the whole foundation under 3 oblique incidences and its calculation accuracy relative to the analytical solution were analyzed.It was shown that when outgoing fields of bottom and right border of foundation are not considered,the calculation error is large;when they are considered,the calculation error is very small,and the maximum error is only-3.8%.Secondly,effects of pulse type and non-pulse ground motions on seismic response of the hydropower house under 3 kinds of free field construction methods were studied.The results showed that the total input energy and damage energy dissipation of the powerhouse have larger increase without considering outgoing fields of bottom and right border of foundation to cause extensive damage of draft tube structure at lower part of the power house and obvious change of the proportion of various energy in the total input energy;under the same free field construction method,the damage ability of pulse type ground motion to the powerhouse is stronger,so attention should be paid to the aseismic design of the powerhouse near the fault area.