(清华大学土木工程系 北京 100084)
【提要】 应用三维有限元方法分析了群桩刚性桩复合地基在地震作用下的动力反应规律，特别是桩体的内力反应。计算表明，由于刚性桩复合地基中垫层的存在，桩顶内力较桩基明显减小，从而使整个桩身的最大内力显著小于桩基。但当桩体位于分层地基，且相邻土层模量差异较大时，地震作用则会使桩体产生较大的内力。【关键词】 刚性桩复合地基 抗震性能 动力有限元
Earthquake Response of Rigid Pile Composite Foundation Analyzed with 3D Dynamic Finite Element Method/Liu Guanglei,Wu Siyu,Song Erxiang(Civil Engineering Department,Tsinghua University,Beijing 100084,China)
Abstract:The seismic behavior of rigid pile composite foundation is analyzed with 3D dy
namic finite element method, with attention focused on the inner force of the piles. Calculations show that due to the effect of the cushion layer in the composite foundation, the inner force at the pile top is very small, and  the maximum inner force in the entire pile is also much smaller than that in the  ordinary pile foundation. If the pile is installed i
n a layered soil with significant modulus difference between its adjacent layers, the inner force in the pile will increase much more under the excitation of earthquakes.
Keywords:rigid pile composite foundation； antiseismic behavior； dynamic finite elements