Acoustic experimental study of two types of rock from the Tibetan Plateau under the condition of freeze-thaw cycles  

作　　者：Hua Liu FuJun Niu ZhiYing Xu ZhanJu Lin Jian Xu 

机构地区：[1]State Key Laboratory of Frozen Soil Engineering, CoM and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China

出　　处：《Research in Cold and Arid Regions》2012年第1期21-27,共7页寒旱区科学（英文版）

基　　金：supported in part by the Important Orientation Projects of the CAS (KZCX2-YW-Q03-04);the Grant of the Western Project Program of the Chinese Academy of Sciences (KZCX2-XB2-10);Natural Science Foundation of China (Grant No. 40625004,40821001)

摘　　要：Under the condition of freeze-thaw cycles, two types of rocks （granite and andesite）, used as slope protection for the Qinghai-Tibet Railway, were tested according to the special climatic conditions in the Tibetan Plateau, and their various damage processes in ap- pearance were carefully observed. Observation results show that damage of andesite was more serious than that of granite. Using an acoustic instrument, ultrasonic velocity was tested. The changing trends of velocity with the number of freeze-thaw cycles were analyzed, and the freeze-thaw cycle damaging the physical and mechanical properties of rocks can be seen. According to the changing trends of ultrasonic velocity with the number of freeze-thaw cycles, mechanical parameters of rocks, such as dynamic elasticity modulus, Poisson＇s ratio, and dynamic bulk modulus were analyzed. It is found that they all have declining trends as the number of fi＇eeze-thaw cycles increases, and in particular, when the cycle number reaches a certain extent, the Poisson＇s ratio of rocks begins to become negative.Under the condition of freeze-thaw cycles, two types of rocks （granite and andesite）, used as slope protection for the Qinghai-Tibet Railway, were tested according to the special climatic conditions in the Tibetan Plateau, and their various damage processes in ap- pearance were carefully observed. Observation results show that damage of andesite was more serious than that of granite. Using an acoustic instrument, ultrasonic velocity was tested. The changing trends of velocity with the number of freeze-thaw cycles were analyzed, and the freeze-thaw cycle damaging the physical and mechanical properties of rocks can be seen. According to the changing trends of ultrasonic velocity with the number of freeze-thaw cycles, mechanical parameters of rocks, such as dynamic elasticity modulus, Poisson＇s ratio, and dynamic bulk modulus were analyzed. It is found that they all have declining trends as the number of fi＇eeze-thaw cycles increases, and in particular, when the cycle number reaches a certain extent, the Poisson＇s ratio of rocks begins to become negative.

关 键 词：freeze-thaw cycle GRANITE ANDESITE ultrasonic wave physical and mechanical properties 

分 类 号：P584[天文地球—岩石学] TU528.01[天文地球—地质学]