风化花岗岩单轴损伤力学特性试验研究

Experimental Study on Damage Mechanical Properties of Weathered Granite

为研究风化花岗岩弹性力学参数的劣化程度,选取弱风化、中风化及强风化的花岗岩进行单轴压缩力学特性试验研究。结果表明:风化作用对花岗岩力学特性有重要影响,会造成弹性参数不同程度的劣化。其中抗压强度和弹性模量随风化作用加强可大幅度降低,强风化花岗岩较之弱风化时抗压强度和弹性模量分别降低到30%和50%,而泊松比成增大趋势且可以增加至弱风化时的1.15倍。受不同风化作用的花岗岩破坏模式均为拉剪破坏,但宏观表现略有不同。根据损伤理论描述了风化花岗岩的损伤演化过程,得出风化花岗岩的相对损伤变量及损伤本构关系。该结论对指导管线穿越河床工程岩体力学及路基土工程有一定参考价值。

Weathering＇s influence on mechanical properties of granite is an important issue. In this research the mechanical deteriorating character of the weak,medium and strong weathering granite under uniaxial compression were tested. The results showed that the weathering effect has important influence on mechanical character of granite,and it cause elastic parameters deterioration in different levels. The compressive strength and elastic modulus of granite are greatly reduced with the intensification of weathering,these values of the strong weathering granite decrease to 30% and 50% of the weak weathering granite. But Poisson＇s ratio increase to more than 1. 15 times of the weak weathering granite. The failure mode of granite with different weathering are tensile-shear failure,the macroscopic expression of these failure modes varies slightly. The damage evolvement process of weathered granite are described based on damage theory,the relative damage variable and constitutive model of weathered granite are gained. The conclusion could provide referencing value for the granite subgrade soil engineering and the pipeline across the riverbed engineering rock mechanics problems.