【摘要】 为全面掌握核电超大型冷却塔的抗震性能,首先进行结构的模态分析,然后采用振型分解反应谱法和弹性时程分析方法,计算结构在多遇地震作用下的响应,并对结构进行考虑材料和几何非线性的动力弹塑性时程分析,得到结构在罕遇地震作用下的响应。由于超大塔支柱跨度达到170m,还首次对结构进行了考虑行波效应的多点激励分析。结果表明:结构前8阶振型以局部振动为主,直到第9阶出现整体倾覆振型。在多遇地震作用下,支柱的最大位移和基底剪力均满足规范要求,且水平地震反应远大于竖向地震反应。在罕遇地震作用下,支撑结构位移角远小于规范限值,出现的塑性铰数量较少,且主要分布在支柱与壳体的连接处。多点输入对支柱内力影响较为不利,而对支柱位移和塔筒内力影响较小,塑性铰出现的数量稍多且破坏程度更加严重。更多还原

【Abstract】 To study the seismic performance of a super large cooling tower,the modal analysis was carried out at first,then the mode-superposition response spectrum analysis and the elastic time history analysis were carried out to calculate the responses of the structure under frequent earthquake,and the dynamic elasto-plastic time history analysis was done considering the material and geometric nonlinearity.Because the structural length is close to 170 m,multi-support excitation analysis was carried out to study the influence of the traveling wave effect.The result is that,the first eight modal shapes are all local vibrations,and the vibration as a whole appears in mode nine.The biggest displacement and the base shear under frequent earthquake satisfies the code requirement.Under the rare earthquake,the maximum top drift angle of the supporting columns is much less than the limit value and there appears only a few plastic hinges in the joints of column and shell.The earthquake responses of the structure and the columns under multi-support excitations are stronger than that under uniform excitation.更多还原