Effect of freeze-thaw cycles on uniaxial mechanical properties of cohesive coarse-grained soils

作     者：QU Yong-long CHEN Guo-liang NIU Fu-jun NI Wan-kui MU Yan-hu LUO Jing 

作者机构：College of Geology Engineering and Geomatics Chang' an University Xi'an 710054 China China Gold Group Tibet Tyrone Mining Development Co. Ltd. Tibet 850000 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China South China Institute of Geotechnical Engineering School of Civil Engineering and Transportation South China University of Technology Guangzhou 510641 China 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2019年第16卷第9期

页      面：2159-2170页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 0303[法学-社会学] 0708[理学-地球物理学] 0818[工学-地质资源与地质工程] 0705[理学-地理学] 0815[工学-水利工程] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0813[工学-建筑学] 0704[理学-天文学] 0833[工学-城乡规划学] 0713[理学-生态学] 0834[工学-风景园林学（可授工学、农学学位）] 

基　　金：supported by the National Key R&D Program of China (Grant No. 2018YFC1505001) the Key Scientific Research Project of China Gold Group (Grant No. 2016ZGHJ/XZHTL-YQSC-26) the funding from the Department of Transportation of Gansu Province (Grant No. 2017-008) the Fundamental Research Funds for the Central Universities, CHD (Grant No. 300102268716) 

主　　题：Freeze thaw cycles Residual strength Resilient modulus Softening modulus Uniaxial compressive strength Slope stability 

摘      要：Freeze-thaw cycles are closely related to the slope instability in high-altitude mountain regions. In this study, cohesive coarse-grained soils were collected from a high-altitude slope in the Qinghai–Tibet Plateau to study the effect of cyclic freeze-thaw on their uniaxial mechanical properties. The soil specimens were remolded with three dry densities and three moisture contents. Then, after performing a series of freeze-thaw tests in a closed system without water supply, the soil specimens were subjected to a uniaxial compression test. The results showed that the stress-strain curves of the tested soils mainly performed as strain-softening. The softening feature intensified with the increasing dry density but weakened with an increase in freeze-thaw cycles and moisture content. The uniaxial compressive strength, resilient modulus, residual strength and softening modulus decreased considerably with the increase of freeze-thaw cycles. After more than nine freeze-thaw cycles, these four parameters tended to be stable. These parameters increased with the increase of dry density and decreased with the increasing moisture content, except for the residual strength which did not exhibit any clear variation with an increase in moisture content. The residual strength, however, generally increased with an increase in dry density. The soil structural damage caused by frozen water expansion during the freeze-thaw is the major cause for the changes in mechanical behaviors of cohesive coarse-grained soils. With results in this study, the deterioration effect of freeze-thaw cycles on the mechanical properties of soils should be considered during the slope stability analysis in high-altitude mountain regions.