With the steady development of the development of the western region in China, the construction of mountain highways has developed rapidly, and the soil-rock mixed filler, as an excellent filler, is widely used in the subgrade filling of mountain highways. Unlike ordinary fine-grained soil, the source of the soil-rock mixtures (S-RMs) is not unique, and the particle size difference is large and the water content is not uniform, resulting in very complicated mechanical properties. But the current highway embankment codes are still mainly established on the fine-grained soil. It is not fully applicable to soil-rock filled embankment. Based on soil-rock filled embankment engineering practice, this research uses a large-scale direct shear test to research the mechanical characteristics of the S-RMs with different maximum particle diameters. According to the large-scale direct shear test of S-RMs with different maximum particle diameters, the shear displacement vs shear stress curve, shear dilation, and strength characteristics with maximum particle diameter were analyzed. Results demonstrate that whether secondary hardening occurs mainly depends on the normal stress and the maximum particle diameter of the filler. At different maximum particle diameters, the horizontal displacement vs vertical displacement curves of the S-RMs can be roughly divided into continuous shearing and beginning of shearing and quick dilation. And the shear strength increases with the increase of the maximum particle diameter. Moreover, the cohesion decreases first and then increases with the increase of the maximum particle diameter, and the internal friction angle increases with the increase of the maximum particle diameter. Therefore, some RBs with large particle diameter added to filler can effectively improve the shear strength of the S-RMs, which may be valuable for realistic engineering.

中文翻译：

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最大粒径对土石混合料力学行为的影响

随着我国西部大开发的稳定发展，山区公路建设发展迅速，土石混合填料作为一种优良的填料，被广泛用于山区公路的路基填筑。与普通的细粒土壤不同，土壤-岩石混合物（S-RMs）的来源不是唯一的，且粒径差异大且含水量不均匀，从而导致非常复杂的机械性能。但是，当前的高速公路路堤法规仍主要建立在细粒土壤上。它不适用于土石填方路堤。基于土石填筑路堤工程实践，本研究采用大型直接剪切试验研究了最大粒径不同的S-RMs的力学特性。根据不同最大粒径的S-RMs的大规模直接剪切试验，分析了剪切位移-剪切应力曲线，剪切膨胀和最大粒径下的强度特性。结果表明，是否发生二次硬化主要取决于法向应力和填料的最大粒径。在不同的最大粒径下，S-RMs的水平位移与垂直位移曲线可以大致分为连续剪切，剪切开始和快速膨胀。并且，剪切强度随着最大粒径的增加而增加。而且，随着最大粒径的增加，内聚力先下降，然后增加，内摩擦角随最大粒径的增加而增大。因此，一些添加到填料中的大粒径RB可以有效地提高S-RM的剪切强度，这对于实际工程可能是有价值的。