干湿交替中砂岩强度与波速关系的试验研究

Experimental Research on Relationship between Stength of Sandstone and Wave Velocity During Wet and Dry Cycles

库水周期性干湿循环作用使得库岸边坡消落带岩土体的强度发生劣化,当劣化发展到一定程度的时候就可能会引起岸坡失稳.不同类型的岩土体遇水后,其强度劣化程度因岩土体的岩性不同而不同.本文以两种不同矿物成份的砂岩为研究对象,进行室内超声波测试、单轴抗压试验,探讨干湿循环作用下其强度劣化情况以及强度与纵波波速之间的相关关系.试验结果表明:干湿循环作用下砂岩的纵波波速与单轴抗压强度有很好的对应关系.Ⅰ号砂岩遇水后,波速与强度均有相应的大幅度衰减,多次干湿循环之后,波速与强度趋于平稳;Ⅱ号砂岩在经历多次干湿循环之后,波速与强度均未发生显著的劣化.

Reservoir water makes periodic wet and dry cycles with fluctuating bank slopes of the strength of rock and soil degradation occurs;when developed to a certain degree of deterioration,it may cause slope instability.Different types of rock and soil under water,its intensity and degree of degradation of the lithology of rock and soil vary.Taking two different mineral composition of sandstone as the research object,indoor ultrasonic test,uniaxial compression tests are carried out to explore the effect of wet and dry cycles on degradation of its strength,and relationship between intensity and longitudinal wave velocity.The results show that： under wet and dry cycles,the relationship between longitudinal wave velocity of sandstone and uniaxial compressive strength has good correspondence.Red sandstone under water,the wave velocity and attenuation of intensity are appropriate;multiple wet and dry cycles,the velocity and intensity stabilized;green sandstone after going through several cycles of wet and dry,velocity and intensity did not occur significant deterioration.