中文摘要：

为探究含水率变化对桃坪冰水堆积物抗剪强度的影响,取原状土样进行了6种不同含水率条件下的不固结不排水三轴剪切试验,并结合土水特征曲线探讨了该类特殊土体的非饱和强度特性。含水率对桃坪冰水堆积物的抗剪强度有着显著的影响,其饱和时的黏聚力和内摩擦角比天然含水率情况分别降低40.0%和29.5%。建立了桃坪冰水堆积物非饱和黏聚力与含水率参数χ（w）的关系式,实际应用时可采用指数函数来确定χ（w）。含水率增大使冰水堆积物基质吸力迅速减小,其抑制土颗粒塑性滑动的能力大幅降低,土体中细小裂纹不断发育、扩张,导致其宏微观结构遭受破坏、抗剪强度出现衰减。针对桃坪堆积体上广泛存在的浅层滑坡,应积极开展堆积区降雨量动态监测、优化改进灌溉方式以及加强坡体表部排水设施建设等工作。

英文摘要：

This paper investigates the influence of water content on shear strength of glaciofluvial deposits in Taoping area. Unconsolidated undrained triaxial shear tests were conducted on original samples with six different water content conditions. The unsaturated strength characteristics of this special soil are discussed by combining the soil water characteristic curve. Water content has a significant effect on the shear strength of the breccia soil in Taoping deposit.When the soil is saturated,its cohesion and internal friction angle are 40. 0% and 29. 5%lower than that in the case of natural water content. The increase of water content causes the matrix suction of glaciofluvial deposits to decrease rapidly,and the ability to suppress the plastic sliding of soil particles is greatly reduced. The fine cracks in the soil are continuously developed and expanded,resulting in the destruction of macro-microstructure and the attenuation ofshear strength. Aiming at the shallow landslides which are widespread on the slope,it is necessary to carry out dynamic monitoring of rainfall in the accumulation area,to optimize the irrigation method and to strengthen the construction of the drainage system.