冻融循环条件下英安岩的物理力学特性试验研究

Experimental Study on Physical and Mechanical Properties of Rock under the Condition of Freeze-thaw Cycles

通过模拟高寒地区自然条件,对西藏某电站坝址英安岩进行饱水条件下冻融循环试验、电镜扫描试验和单轴、三轴抗压强度试验。通过对冻融循环条件下英安岩的物理特性(质量变化、声波变化、微观裂隙发展)和力学特性的研究,发现冻融循环作用会导致岩石内部裂隙扩展和颗粒析出,且后者劣化程度明显弱于前者,但最终均趋于稳定;同时,随冻融循环次数的增加,岩石强度参数值逐渐减小、抗冻性减弱,而围压的增加却能够弱化冻融循环对英安岩的损伤。

By simulating the natural condition of the alpine region,a power station in Tibet dam dacite were saturated under freeze-thaw cycle test and SEM test and uniaxial compressive strength test,three axis. The physical characteristics of the freeze-thaw cycle under the condition of dacite（ mass change,sound velocity change,research and development of micro cracks） mechanical properties,found that freeze-thaw cycles will lead to internal rock expansion and particle precipitation,and the degree of degradation was significantly weaker than the former,but eventually tends to be stable; at the same time,with the increase in the number of freeze-thaw cycles,the rock strength parameters decrease,frost resistance decreased,while the increase in confining pressure can weaken the freeze-thaw cycle of dacite damage.