土石混合体在组成结构、力学性质和变形行为等方面显著区别于均质土体和岩石。结合土石混合体的细观结构特征,将其看作由块石和土体基质组成的两相复合材料,提出了土石混合体宏观力学特性分析的细观尺度多步等效化分析方法,继而对该分析方法中两个核心问题,即块石粒径阈值及复合材料等效化问题分别进行了研究。该方法的本质思想是:首先将较小粒径块石与土体基质进行均匀化处理,获得其各向同性的等效均匀介质;其次,将较大粒径的块石投放进等效均匀介质中,形成新的混合体,进而再次基于有限元数值方法对新混合体的力学特性及变形规律进行研究。基于该套分析方法对某土石混合体三轴加载排水试验进行了模拟与分析,发现该文方法获得的结果与试验结果吻合良好,验证了方法的有效性。
Soil-rock mixture is significantly different from soil and rock in structure, mechanical properties and deformation behavior. Considering the mesoscopic structure of soil-rock mixture which can be treated as a two-phase composite of rock blocks and soil, a mesoscopic equivalent analysis method for studying the macro-mechanical properties of soil-rock mixture is proposed. Two key problems of the method, mainly about the rock size threshold and equivalent method of soil-rock mixture, are discussed. Firstly, homogenization process is conducted on the "small" stones and soil to obtain the equivalent homogeneous isotropic matrix. Then the new soil-rock mixture is formed by placing the "big" stones in the equivalent matrix, and its mechanical behavior and deformation feature are analyzed using numerical approaches. Based on the method, consolidated drained triaxial tests of soil-rock mixture are simulated. The analysis shows that the results obtained by the mesoscopic equivalent analysis method are in good agreement with those obtained by the tests, thus proves the efficiency of the method.