Experimental study of influence of freeze-thaw cycles on damping ratio of remolded Qinghai—Tibet silty clay
SU Yongqi1，2，3，MA Wei2，ZHONG Xiumei4，WANG Qian4，MU Yanhu2
(1. Gansu Bureau of Coal Geology，Lanzhou，Gansu 730000，China；2. State Key Laboratory of Frozen Soil Engineering，Northwest Institute of Eco-Environment and Resources，Chinese Academy of Sciences，Lanzhou，Gansu 730000，China；3. University of Chinese Academy of Sciences，Beijing 100049，China；4. Lanzhou Institute of Seismology，China Earthquake Administration，Lanzhou，Gansu 730000，China)
Abstract：Damping ratio is one of the important dynamic parameters of soil. Based on the freeze-thaw cycles tests，the dynamic triaxial tests are carried out to study the damping ratio of remolded Qinghai—Tibet silty clay under dynamic loading. In the test，the influences of the freeze-thaw cycles，water content and dynamic loading frequency are considered. The relationship curve and model parameters of damping ratio vs. dynamic shear strain( - ) are obtained. The results indicate that the damping ratio of remolded Qinghai—Tibet silty clay under dynamic loading is most significantly affected by moisture content，significantly affected by freeze-thaw cycles，and less affected by dynamic loading frequency. With the increase of the number of freeze-thaw cycles，the - curve shifts upward and the damping ratio corresponding to the same dynamic shear strain increases，the - curve changes most significantly after one freeze-thaw cycle，then tends to be stable after three freeze-thaw cycles. With the increase of the water content，the - curve keeps moving upward，the shape of the curve also changes gradually from gentle to steep，and the damping ratio corresponding to the same dynamic shear strain generally increases. With the increase of the dynamic loading frequency，the - curve moves down slowly，and the damping ratio corresponding to the same dynamic shear strain decreases slightly. The research results can provide a reference for the selection of the damping ratio parameters in the seismic response analysis and foundation dynamic response analysis in cold region.
苏永奇1，2，3，马 巍2，钟秀梅4，王 谦4，穆彦虎2. 冻融循环对重塑青藏粉质黏土阻尼比影响的试验研究[J]. 岩石力学与工程学报, 2021, 40(S1): 2960-2967.
SU Yongqi1，2，3，MA Wei2，ZHONG Xiumei4，WANG Qian4，MU Yanhu2. Experimental study of influence of freeze-thaw cycles on damping ratio of remolded Qinghai—Tibet silty clay. , 2021, 40(S1): 2960-2967.
2021, Vol. 40 
