【摘要】 建立了简谐剪切地震波激励下三维土桩结构线性耦合体系简化分析模型,桩和结构均被简化为一简单梁模型;对耦合体系桩承台对基岩运动的放大效应进行了求解,此放大效应反映了耦合体系的动力相互作用.通过算例讨论了结构高度、刚度和质量、土层厚度和刚度以及桩刚度对耦合体系放大效应和固有频率的影响,结果表明:耦合体系的固有频率随结构高度、质量或土厚度的增加而减小,随结构刚度或土刚度的增大而增大.结构高度、刚度和质量以及土层厚度、刚度对耦合体系放大效应的影响无简单规律可循,而桩刚度对其影响不大.在与自由场地表面对基岩运动放大效应的比较中可知,在某些桩基结构的动力分析和设计中耦合体系动力相互作用不应忽略.这为进行土桩结构动力相互作用详细数值分析和试验研究建立了初步认识.更多还原

【Abstract】 A simple three-dimensional model was proposed for the linear interaction analysis of a fully coupled soil-pile-structure system subjected to the harmonic shear seismic wave.Both piles and structure were simplified as a beam model.Then,the amplitude amplification for the pile cap response of the coupled system to the bedrock shaking was obtained,and the dynamic interaction was reflected.An example showed that the predominant frequencies decreased with the increase of the height,the mass of the structure or the thickness of the soil,but increased with the increase of the stiffness of the structure or the soil.The height of the structure influenced the amplification for the coupled system without a simple rule,so did the stiffness,the mass of the structure,the thickness and the stiffness of the soil.But the stiffness of the pile had few effect on it.Through comparing the amplification for coupleld system with the amplitude amplification for the surface response of the free site to the bedrock shaking,it was also proved that the dynamic interaction of a coupled system could not be ignored in the dynamic analysis and design of structures piled onto soils.This was a foundation for detailed numerical analysis and experiment researches on the soil-pile-structure dynamic interaction.更多还原