土体抗剪强度的尺寸效应

从材料的微观力学性质入手，用纤维束强度理论，得到了材料的宏观统计力学效应．以土力学强度实验中广泛采用的小尺寸、中尺寸和大尺寸实验为基础，对某土体强度进行了统计分析和蒙特卡洛模拟，统计结果揭示了土体强度的统计尺寸效应．研究表明，不同尺寸岩土体试样强度的实验结果不同，按纤维束强度理论解释较为吻合；当土体试样尺寸大于中尺寸后，强度参数趋于稳定，试样强度的代表性好．

Investigation on Size Effect of Shear Strength of Soil

Based on the micro mechanical feature of materials and the strength theory of fibrous bunchiness, the macro statistical size effect of materials was gained. As an example, the shear strength of specimens from a concrete project with three scales, i.e., small, medium and big sizes widely adopted in soil strength tests, was discussed using the statistical analysis and the Monte-Carlo method. The result shows the statistical size effect of soil shear strength. The research indicates that different sizes of specimens result in different values of soil shear strength, and this phenomenon can be well explained using the strength theory of fibrous bunchiness. When the size of a soil specimen is bigger than medium size, its shear strength tends to be unchanged.