考虑颗粒破碎影响的粗粒土临界状态研究

粗粒土的临界状态是构建本构模型的重要工具,目前考虑颗粒破碎影响的粗粒土临界状态并不明确。通过大型三轴CD试验,研究了粗粒土在临界状态时的颗粒破碎规律和应力变形特性,探讨了颗粒破碎对粗粒土临界状态应力比和临界状态方程参数的影响。主要结论如下:①粗粒土的临界状态应力比M_c并不是定值,而是与围压之间呈现出非线性的关系;②初始孔隙比对于临界状态应力比M_c的影响则可以忽略;③初始级配相同,围压和初始孔隙比不同的粗粒土,其临界状态在e–(p/p_a)~ξ平面可以用同一条直线来描述,且直线的参数是与初始孔隙比和围压无关的常数。

Influences of particle breakage on critical state of coarse-grained soils

The critical state of coarse-grained soils is the important tool to study the constitutive model, however, the critical state of coarse soil considering the effect of particle breakage is not clear. The influences of particle breakage on the stress and deformation properties and the critical state of rockfills are studied through the large-scale triaxial CD tests. The main conclusions are as follows: (1) The critical-state stress ratio M_c of rockfill materials is not a constant, which is found to be passively correlated with the confining pressure. (2) While the effect of void ratio on M_c can be neglected. (3) The critical state of rockfill samples with different confining pressures and void ratios can be described by the same straight line in e-(p/p_a)^ξ plane, and the parameters of the straight line are constant.