摘要
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种斜入射下整个地基的自由场及其相对于解析解的计算精度,不考虑地基底部和右侧边界外行场时,计算误差较大;考虑地基底部边界和右侧边界外行场时计算误差很小,最大误差仅为-3.8%。研究了3种自由场构建方法下脉冲型和非脉冲地震动对水电站厂房地震响应的影响。结果表明:不考虑地基底边界和右侧边界外行场时,厂房总输入能和损伤耗散能有较大增加,导致厂房下部尾水管结构出现大范围的损伤破坏,并且各项能量占总输入能的比重发生明显变化;在相同自由场构建方法下,脉冲型地震动对厂房的破坏能力更强,因此近断层区域内厂房的抗震设计应该引起重视。
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.
作者
王飞
宋志强
刘云贺
张剑峰
WANG Fei;SONG Zhiqiang;LIU Yunhe;ZHANG Jianfeng(State Key Laboratory of Eco-Hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China;China Three-Gorge Projects Development Co.,Ltd.,Chengdu 610041,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2021年第7期9-18,共10页
Journal of Vibration and Shock
基金
国家自然科学基金重点项目(52039008)
国家自然科学基金(51479165,51779208)。
关键词
水电站地面厂房
地震波斜入射
自由场
脉冲型地震动
能量
ground hydropower house
seismic wave oblique incidence
free-field
pulse type ground motion
energy
