循环荷载作用下考虑Hansbo渗流的饱和黏土固结分析
CONSOLIDATION ANALYSIS OF SATURATED CLAY WITH CONSIDERATION OF HANSBO'S FLOW UNDER CYCLIC LOADING
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摘要: 针对传统一维Terzaghi固结理论的局限性,本文引入了考虑时间效应的UH (unified hardening)本构模型,将Hansbo渗流模型耦合到UH本构模型固结方程中,建立了几种典型循环荷载作用下基于UH模型和考虑Hansbo渗流模型的固结方程。采用FlexPDE软件进行了数值分析,将计算结果与已有文献结果对比,验证了该算法的可靠性。在此基础上,研究了饱和黏土在几种典型循环荷载作用下的渗流固结特性,分析了各模型参数对饱和黏土固结特性的影响。结果表明:在循环荷载作用下,地基的平均固结度、沉降量等始终处于循环状态;Hansbo渗流模型参数对平均固结度的影响相对于Darcy渗流参数影响程度较大,其中UH模型中次固结系数对固结过程影响程度较大。另外,Hansbo渗流参数及土的回弹指数和渗透指数等对固结过程的影响主要体现在中期,固结过程后期将处于稳定循环状态。Abstract: The limitations of the traditional one-dimensional Terzaghi consolidation theory are more and more felt. In this paper, the unified hardening (UH) constitutive model with consideration of the time effect is used, with the Hansbo's flow model coupled with the consolidation equation of the UH constitutive model, and the consolidation equations based on the UH model and the Hansbo's flow model under several typical cyclic loads are established. Numerical analysis is carried out by using the FlexPDE software, and the reliability of the algorithm is verified by comparing the calculation results with those in the literature. On this basis, the seepage consolidation characteristics of the saturated clay under several typical cyclic loads are studied, and the influence of the model parameters on the consolidation characteristics of the saturated clay is analyzed. The results show that: under the cyclic loading, the average consolidation degree and the settlement of the foundation are always in a cyclic state; the influence of the Hansbo's flow model parameters on the average consolidation degree is greater than that of the Darcy's flow parameters, and the secondary consolidation coefficient in the UH model has a greater influence on the consolidation process. In addition, the influence of the Hansbo's flow parameters and the soil rebound index and permeability index on the consolidation process is mainly reflected in the middle stage, and the later stage of the consolidation process will be in a stable circulation state.