含砾量对饱和砂-砾混合料排水剪切强度的影响

为探讨含砾量Gc对砂-砾混合料排水剪切强度Sd的影响，对砂-砾混合料开展了一系列三轴排水试验。结果表明，Gc不同的混合料的应力-应变关系曲线呈应变硬化型和应变软化型2种不同的发展模式，随着Gc的增加，无论砂-砾混合料处于松散(Dr=0.2)、中密(Dr=0.4、0.6)还是密实(Dr=0.8)状态，排水剪切强度Sd均先略有降低后保持不变，最后迅速增加。研究发现，e、Cu、Cc和d50都不能作为合理描述不同Gc的砂-砾混合料Sd的参数，而具有不同Gc和Dr的砾-砂混合料的Sd均随等效骨架孔隙比esk的增大而降低，表明esk可以合理地表征砂-砾混合料Sd的物理状态。

Effect of gravel content on drainage shear strength of saturated sand-gravel mixture

To investigate the effect of gravel content (Gc) on the drainage shear strength (Sd) of sand-gravel mixture, a series of triaxial drainage tests were carried out on sand-gravel mixtures. The results show that the stress-strain relationship curves of the mixtures with different Gc values show two different development modes: strain hardening and strain softening. With the increase of Gc values, whether the sand-gravel mixture was loose (Dr=0.2), medium dense (Dr=0.4 and 0.6) or dense (Dr=0.8), the drainage shear strength (Sd) was slightly reduced and then maintained with no change, and finally increased rapidly. It was found that e, Cu, Cc and d50 could not be used as parameters to reasonably describe the drainage shear strength of sand-gravel mixtures of different Gc values. In addition, the drainage shear strength of the gravel-sand mixtures with different Gc values and Dr decreases with the increase of the equivalent skeleton porosity ratio (esk), which indicates that esk can reasonably characterize the physical state of the sand-gravel mixture Sd.