PROGRESSIVE FAILURE OF GEO-STRUCTURE AND STRAIN LOCALIZATION

进行了室内单元试验和模型试验，研究了岩土材料从初始状态到破坏状态的微观结构变化。在实验结果的基础上，建立了基于细观力学的本构模型。在此基础上，采用数值方法对本构模型进行了非局部处理，避免了控制方程在数值分析中的不适定性。2)研究了离散元方法在数值分析中的作用。3)详细研究了分叉理论和分岔点后的力学行为。4)提出了土水耦合有限元方法来模拟岩土材料在临界点附近的力学行为。

Laboratory element tests as well as model tests have been carried out to investigate the change of microstructure of the geomaterials from the initail state to the failure state. The strain localization behavior were observed.Base on the experimental results, micromechanics-based constitutive models have been proposed. Then these models have been implemented in the numerical method.1) The nonlocal treatments of the constitutive models were proposed to avoid the ill-posedness of the governing equations in the numerical analyzes.2) The role of distinct element method has been investigated.3) The bifurcation theory and the mechanical behavior after the bifurcation point have been carefully investigated.4) Soil-water coupled finite element method has been proposed to simulate the mechanical behavior of geomaterials near/at critical state.