多元复合地基的等效本构模型及三维地震响应研究

Research in equivalent constitutive relation and three directions seismic responses of multi-element composite foundation

按照复合材料力学的处理方法将多元复合地基的桩-土体系作等效连续化处理,将其视为横观各向同性体,首次建立了多元复合地基桩土等效复合体的本构关系;基于大型有限元软件ABAQUS操作平台,采用有限元、无限元耦合的方法研究了多元复合地基的三维地震响应,结果表明:(1)等效复合体模型能很好地反映出多元复合地基的传力机理.(2)天然地基、多元复合地基和基础在地表的加速度傅氏谱均呈多峰型,对输入地震波均有滤波作用,且多元复合地基和基础的滤波作用更为显著.(3)褥垫层、筏板的增加能有效抑制地表加速度响应,但并非越厚越好,还要考虑建造的经济性.计算结果可为工程抗震设计提供参考.

The equivalent continuous processing is done to multi-element composite foundation by composite material me- chanics method, the composite foundation is studied as transversely isotropic body, and the constitutive relation of equiva lent complex is established at first time. On the ABAQUS platform, the three direction seismic responses of multi-ele- ment composite foundation are studied by finite-infinite element coupling method. The results show that： （1） the model of equivalent complex can reflect the working mechanics of the multi-element composite foundation; （2）The accelerations fourier spectrum at earth surface of natural foundation, multi element composite foundation and ground are multi-peak types, and all of them have filter action to input earthquake wave, and the actions of multi-element composite foundation and ground are stronger than that of the natural foundation, and the（3） cushion and raft can limit the acceleration respon ses at earth surface, but the effect does not increase with the depth of cushion and raft. The economical efficiency should be considered too. The results can provide reference for the seismic design of engineering.