The mechanical behaviors of soil-rock mixture (S-RM) are very complicated and significantly affected by its rock block content and gradation composition. A systematic study was performed on how the strength and failure characteristics of S-RM can be affected by the rock block content, the “oversize rock block” processing methods adopted, and the sample size in triaxial tests. Both the deviator stress ratio and friction strength of S-RM increase together with the rock block content, but the former tends to decrease as the confining pressure increases. In the case of S-RM samples with the same gradation, these two parameters tend to decrease as the sample scale becomes larger. The development of deviator stress over axial strain of samples prepared using the equal quantity substitution method is similar to that of the samples of the natural gradation. During the shearing process, some large rock blocks in S-RM will be broken. The breakage mode of the rock blocks can be primarily divided into four categories according to its mechanism, namely, disintegration, corner breakage, fracturing, and breakage along bedding faces. As a result of the breakage, the strength envelope curve of S-RM follows a power function.

土石混合物（S-RM）的力学行为非常复杂，并受其岩块含量和级配组成的显着影响。对岩石块含量，采用的“超大型岩石块”加工方法以及三轴试验中的样本量如何影响S-RM的强度和破坏特性进行了系统的研究。S-RM的偏应力比和摩擦强度都随岩石块含量的增加而增加，但随着围压的增加，前者趋于减小。对于具有相同等级的S-RM样品，这两个参数会随着样品规模的增大而降低。用等量代入法制备的样品在轴向应变上的偏应力发展与自然渐变样品相似。在剪切过程中，S-RM中的一些大块岩石将被破碎。岩石块的破碎方式根据其机理可分为四类，即崩解，拐角破碎，断裂和顺层破碎。断裂的结果是，S-RM的强度包络线遵循幂函数。