提出了考虑桩-土-结构动力相互作用的输电塔地震反应分析方法。通过采用粘弹性人工边界模拟土体边界,用改进的Goodman单元模拟桩.土接触面,建立了桩-土-输电塔体系相互作用模型。以一具体输电塔为例,在四种不同的场地条件下,对桩-土-输电塔体系在地震作用下的动力反应进行分析,并与不考虑桩-土-结构动力相互作用的计算结果进行对比。结果表明:在软土及中软场地,考虑相互作用计算出的塔体位移和构件应力均大于不考虑相互作用的计算结果;在中硬及硬土场地,二者区别不大。建议在软土和中软场地,进行输电塔抗震设计应充分考虑桩-土-结构的动力相互作用。
The seismic response analysis method of transmission tower in consideration of pile-soil-structure dynamic interaction is presented. Pile-soil-transmission tower coupled system is set up with visco-elastic artificial boundary as the soil boundary and modified Goodman element as the pile-soil interaction face. The seismic response of a pile-soil-transmission tower system under four different site conditions is calculated, and compared with the results that do not consider the effect of pile-soil-structure dynamic interaction. It can be concluded that the displacement of tower and the stress of the members substantially increased on soft sites and medium soft sites while no significant change on medium hard sites and hard sites when pile-soil-structure dynamic interaction is considered. Therefore it is suggested that the pile-soil-structure dynamic interaction should be fully considered in aseismic design of transmission tower on soft sites and medium soft sites.