(1. Key Laboratory of Soft Soil Engineering Character and Engineering Environment of Tianjin，Tianjin Chengjian University，Tianjin 300384，China；2. School of Civil Engineering，Tianjin Chengjian University，Tianjin 300384，China；
3. School of Civil Engineering，Tianjin University，Tianjin 300072，China)
Abstract：Through a self-improved temperature controlled triaxial apparatus，the consolidated undrained shear test after freeze-thaw(FC mode) and unconsolidated undrained shear test after freeze-thaw(CF mode) were carried out on the remolded muddy soil，considering the combined effects of freeze-thaw confining pressure，times and freezing temperature. The effects of the above factors on the mechanical properties of the remolded soil were analyzed. The influence mechanism of freeze-thaw confining pressure on the mechanical properties was revealed by SEM. The results show that the confining pressure during freeze-thaw cycles reduces the number of pores in the soil after freezing and thawing，thus reducing the weakening effect of freezing and thawing on the strength and modulus in FC mode. While in CF mode，the freezing and thawing confining pressure increases the pores in the soil after freezing and thawing，and the excess pore pressure in the soil increases without dissipation during the soil thawing，which further aggravates the weakening effect of freezing and thawing on the strength and modulus of the soil. In two modes，the lower the freezing temperature and the greater the number of freeze-thaw cycles，the more obvious the strength weakening effect of the muddy soil, and the higher the excess pore water pressure when the soil is yield. The variation rules of mechanical index deterioration coefficient of the muddy soil with freeze-thaw confining pressure，times and freezing temperature can be described by a growth function.
张建新1，2，马昌虎2，郎瑞卿1，2，孙立强3，闫澍旺3. 不同冻融模式下淤泥质土力学及微观结构特性研究[J]. 岩石力学与工程学报, 2023, 42(S1): 3801-3811.
ZHANG Jianxin1，2，MA Changhu2，LANG Ruiqing1，2，SUN Liqiang3，YAN Shuwang3. Experimental study on mechanical properties and microstructure of muddy soil under different freeze-thaw modes. , 2023, 42(S1): 3801-3811.
[1] SANG Y K，PARK J，CHA W，et al. Soil response during globally drained and undrained freeze–thaw cycles under deviatoric loading[J]. Journal of Geotechnical and Geoenvironmental Engineering，2021，147(2)：06020030.
[2] WANG J，NISHIMURA S，TOKORO T. Laboratory study and interpretation of mechanical behavior of frozen clay through state concept[J]. Soils and Foundations，2017，57(2)：194–210.
[3] CHAMBERLAIN E J，GOW A J. Effect of freezing and thawing on the permeability and structure of soils[J]. Engineering Geology，1979，13(1)：73–92.
[4] LEE W，BOHRA N C，ALTSCHAEFFL A G，et al. Resilient modulus of cohesive soils and the effect of freeze-thaw[J]. Canadian Geotechnical Journal，1995，32(4)：559–568.
[5] SIMONSEN E，ISACSSON U. Soil behavior during freezing and thawing using variable and constant confining pressure triaxial tests[J]. Canadian Geotechnical Journal，2011，38(4)：863–875.
[6] 胡田飞，刘建坤，房建宏，等. 冻融循环下冷却温度对粉质黏土力学性质影响的试验研究[J]. 岩石力学与工程报，2017，36(7)：1 757– 1 767.(HU Tianfei，LIU Jiankun，FANG Jianhong，et al. Experimental study on the effect of cyclic freezing-thawing on mechanical properties of silty clay under different cooling temperatures[J]. Chinese Journal of Rock Mechanics and Engineering，2017，36(7)：1 757–1 767.(in Chinese))
[7] 王大雁，马 巍，常小晓，等. 冻融循环作用对青藏黏土物理力学性质的影响[J]. 岩石力学与工程学报，2005，24(23)：4 313–4 319. (WANG Dayan，MA Wei，CHANG Xiaoxiao，et al. Physico- mechanical properties changes of Qinghai—Tibet clay due to cyclic freezing and thawing[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(23)：4 313–4 319.(in Chinese))
[8] 于琳琳，徐学燕，邱明国，等. 冻融作用对饱和粉质黏土抗剪性能的影响[J]. 岩土力学，2010，31(8)：2 448–2 452.(YU Linlin，XU Xueyan，QIU Mingguo，et al. Influence of freeze-thaw on shear strength properties of saturated silty clay[J]. Rock and Soil Mechanics，2010，31(8)：2 448–2 452.(in Chinese))
[9] 陶 勇，杨 平，杨国清，等. 冻融作用对海相软土压缩性及抗剪强度影响研究[J]. 冰川冻土，2019，41(3)：637–645.(TAO Yong，YANG Ping，YANG Guoqing，et al. A study on influence of freezing and thawing on compressibility and shear strength of marine soft soil[J]. Journal of Glaciology and Geocryology，2019，41(3)：637–645.(in Chinese))
[10] 孔勃文，丁 智，何绍衡，等. 冻压条件下冻融软土孔隙特征与动力特性分析[J]. 岩石力学与工程学报，2020，39(11)：2 328–2 340. (KONG Bowen，DING Zhi，HE Shaoheng，et al. Experimental study on pore features and dynamic behaviors of soft clay under different confine pressures during freezing[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(11)：2 328–2 340.(in Chinese))
[11] 于啸波，孙 锐，袁晓铭，等. 负温对土动剪切模量阻尼比的影响规律[J]. 岩石力学与工程学报，2016，35(7)：1 452–1 465.(YU Xiaobo，SUN Rui，YUAN Xiaoming，et al. Influence of negative temperature on dynamic shear modulus and damping ratio of soil[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(7)：1 452–1 465.(in Chinese))
[12] 中华人民共和国国家标准编写组. GB/T 50123—1999土工试验方法标准[S]. 北京：中国计划出版社，2008.(The National Standards Compilation Group of People?s Republic of China. GB/T 50123— 1999 standard for geotechnical test methods[S]. Beijing：China Planning Press，2008.(in Chinese))
[13] 陆嘉楠，徐 洁，陈永辉. 温度影响粉质黏土固结和强度特性的试验研究[J]. 防灾减灾工程学报，2017，37(4)：598–603.(LU Jianan，XU Jie，CHEN Yonghui. Experimental study of temperature effects on consolidation and strength properties of silt clay[J]. Journal of Disaster Prevention and Mitigation Engineering，2017，37(4)：598–603.(in Chinese))
[14] CEKEREVAC C，LALOUI L. Experimental study of thermal effects on the mechanical behavior of a clay[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2004，28(3)：209–228.
[15] HAN Y，WANG Q，WANG N，et al. Effect of freeze-thaw cycles on shear strength of saline soil[J]. Cold Regions Science and Technology，2018，154(10)：42–53.
[16] TANG L，CONG S，GENG L，et al. The effect of freeze-thaw cycling on the mechanical properties of expansive soils[J]. Cold Regions Science and Technology，2018，145：197–207.
[17] WANG D Y，MA W，NIU Y H，et al. Effects of cyclic freezing and thawing on mechanical properties of Qinghai—Tibet clay[J]. Cold Regions Science and Technology，2007，48(1)：34–43.
[18] 王 伟，池旭超，张 芳，等. 冻融循环对滨海软土三轴应力应变曲线软化特性的影响[J]. 岩土工程学报，2013，35(增2)：140–144. (WANG Wei，CHI Xuchao，ZHANG Fang，et al. Effect of freeze-thaw circles on softening behaviors of triaxial stress-strain curve of costal soft soils[J]. Chinese Journal of Geotechnical Engineering，2013，35(Supp.2)：140–144.(in Chinese))
[19] 王效宾，杨 平，王海波，等. 冻融作用对黏土力学性能影响的试验研究[J]. 岩土工程学报，2009，31(11)：1 768–1 772.(WANG Xiaobin，YANG Ping，WANG Haibo，et al. Experimental study on effects of freezing and thawing on mechanical properties of clay[J]. Chinese Journal of Geotechnical Engineering，2009，31(11)：1 768– 1 772.(in Chinese))
[20] 陈炜韬，王 鹰，王明年，等. 冻融循环对盐渍土黏聚力影响的试验研究[J]. 岩土力学，2007，28(11)：2 343–2 347.(CHEN Weitao，WANG Ying，WANG Mingnian，et al. Testing study on influence of freezing and thawing circulation on saline soil?s cohesion[J]. Rock and Soil Mechanics，2007，28(11)：2 343–2 347.(in Chinese))
[21] 刘勇健，李彰明. 软土物理力学性质指标与微结构参数的灰色关联–神经网络模型[J]. 岩土力学，2011，32(4)：1 018–1 024.(LIU Yongjian，LI Zhangming. Grey-relation analysis and neural networks model for relationship between physico-mechanical indices and microstructure parameters of soft soils[J]. Rock and Soil Mechanics，2011，32(4)：1 018–1 024.(in Chinese))
2023, Vol. 42 
