基于两相介质理论之土层弹塑性大变形地震反应分析

发布时间：2018-05-03 03:02

本文选题：两相介质 + 非线性动力响应　；参考：《岩土工程学报》2015年11期

【摘要】：基于土水两相混合体完全耦合场方程及土体静动统一本构,构建了新型普适性土层弹塑性大变形地震反应分析方法。考虑强震中土体大变形动力特性描述的困难,基于客观性张量推导,给出了严格的土水两相混合体平衡方程式和连续方程式,分别进行空间和时间离散,编制了显式有限元有限差分程序。通过超固结、结构性和应力诱导各向异性状态变量的引入,建立了物理意义明确的土体静动统一本构,能够合理的表征土体的各类力学特性。数值计算中采用转换应力法,实现了试验应力状态向一般应力状态的拓展,满足复杂三维地层的动力计算需求。通过局部透射人工边界的设置,形成了辐射边界条件,构建了完备的土层反应程序。将分析结果与等效线性化方法和单相介质时域非线性分析结果进行对比,指出饱水砂土层的存在对地震波传播和地表地震动反应特性的影响。
[Abstract]:Based on the fully coupled field equation of soil-water two-phase mixture and the unified constitutive equation of soil static and dynamic, a new generalized soil layer elastic-plastic large deformation seismic response analysis method is constructed. Considering the difficulty of describing the dynamic characteristics of large deformation of soil mass in strong earthquakes, based on the objective derivation of Zhang Liang, a strict equilibrium equation and a continuous equation of soil-water two-phase mixture are given, and the spatial and temporal discretization are carried out, respectively. An explicit finite element finite difference program is developed. Through the introduction of overconsolidation, structural and stress-induced anisotropic state variables, the physical meaning of the soil static and dynamic unified constitutive model is established, which can reasonably represent the various mechanical properties of the soil. The conversion stress method is used in the numerical calculation to extend the experimental stress state to the general stress state and to meet the needs of dynamic calculation of complex three-dimensional strata. By setting the artificial boundary of local transmission, the radiation boundary condition is formed, and a complete program of soil layer reaction is constructed. The results are compared with the equivalent linearization method and the time domain nonlinear analysis results of single-phase medium. It is pointed out that the existence of saturated sand layer has an effect on the seismic wave propagation and the response characteristics of ground motion.
【作者单位】：中国地震局工程力学研究所;日本国立名古屋工业大学;
【基金】：国家自然科学基金项目(51408566,51308512) 中央级公益性研究所基本科研业务费专项项目(2014B03)
【分类号】：TU435;P315.9

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