Abstract：To enhance the long-term service performance of solidified soft soil in plateau regions, this study employed ordinary Portland cement for stabilization. A series of unconfined compression tests, direct shear tests, and microstructural characterization techniques (XRD, SEM, NMR) were utilized to systematically investigate the strength deterioration patterns of cement-stabilized soil under freeze-thaw cycles and elucidate the intrinsic relationship between macroscopic mechanical behavior and microscopic mechanisms. The results show that the strength deterioration of cement-stabilized soil exhibits distinct stage characteristics. The first five freeze-thaw cycles result in the most significant strength reduction, with markedly diminished effects observed thereafter, identifying this initial phase as the critical period for strength degradation. A predictive model based on a 30-year service life established strength deterioration thresholds. The stress-strain curves reveal a three-stage evolution, with specimens demonstrating similar strength development trends in the linear elastic stage across all cement contents, followed by a sharp stress drop post-peak, indicating a notable transition from plastic to brittle failure. The incorporation of cement significantly enhances soil strength, with the unconfined compressive and shear strengths of specimens containing 4%–10% cement after 10 freeze-thaw cycles substantially exceeding those of untreated soil. The increase in cohesion was significantly more pronounced than that of the internal friction angle. Microstructural analysis indicates that repeated freeze-thaw cycles weaken interparticle bonding, reduce particle contacts, and promote pore evolution and development, thereby providing a microscopic interpretation of the macroscopic strength deterioration mechanisms. These findings offer theoretical and technical support for the application of soil stabilization technologies in cold plateau regions.
[1] 尤昌龙，赵成刚，张焕城，等. 高原斜坡软土地基处理实践[J]. 岩石力学与工程学报，2003，22(1)：126–130.(YOU Chonglong，ZHAO Chenggang，ZHANG Huancheng，et al. Subgrade treatment practice of the plateau slope on soft clay[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(1)：126–130.(in Chinese))
[2] 李保琦，张楚楚，周毓彦，等. 1960—2023年我国东北典型季节性冻土区冻融指数及冻土退化影响因素分析[J]. 水利水电技术(中英文)，2024，55(8)：161–173.(LI Baoqi，ZHANG Chuchu，ZHOU Yuyan，et al. Correlation analysis of freezing and thawing index and factors affecting frozen soil degradation in typical seasonally frozen ground in Northeast China during 1960—2023[J]. Water Resources and Hydropower Engineering，2024，55(8)：161–173.(in Chinese))
[3] 刘红平，李 昊，魏 进，等. 考虑细颗粒含量的季冻区公路路基水分迁移特性[J]. 长安大学学报：自然科学版，2024，44(4)：27–37.(LIU Hongping，LI Hao，WEI Jin，et al. Water migration characteristics of highway subgrade in seasonal frozen areas considering fine particle content[J]. Journal of Chang′an University：Natural Science，2024，44(4)：27–37.(in Chinese))
[4] 朱剑锋，汪正清，陶燕丽，等. 电石渣–草木灰复合固化剂固化废弃软土微观特性研究[J]. 土木工程学报，2023，56(10)：180–189.(ZHU Jianfeng，WANG Zhenqing，TAO Yanli，et al. Study on micro characteristics of waste soft solidified by calcium carbide slag plant ash composite curing agent[J]. China Civil Engineering Journal，2023，56(10)：180–189.(in Chinese))
[5] 朱晨俊，温小栋，吴佳育，等. 基于MICP技术的海上风电场滩涂软土固化试验研究[J]. 太阳能学报，2024，45(11)：467–476.(ZHU Chenjun，WEN Xiaodong，WU Jiayu，et al. Experimental investigation on consolidation of soft soil in mudflat of offshore wind farm based on MICP technology[J]. Acta Energiae Solaris Sinica，2024，45(11)：467–476.(in Chinese))
[6] 王 欢，张佳伟，郭合家. EICP改良膨胀土的物理力学性质试验研究[J]. 土木与环境工程学报(中英文)，2024，46(5)：109–116.(WANG Huan，ZHANG Jiawei，GUO Hejia. Experimental study on physical and mechanical properties of expansive soil improved by EICP[J]. Journal of Civil and Environmental Engineering，2024，46(5)：109–116.(in Chinese))
[7] 贾敏才，刘 波，周训军. 滨海含软土夹层粉细砂地基高能级强夯加固试验研究[J]. 建筑结构学报，2019，40(11)：240–246.(JIA Mincai，LIU Bo，ZHOU Xunjun. Field test study of high energy dynamic compaction on marine silty fine sand deposits with soft interlayers[J]. Journal of Building Structures，2019，40(11)：240–246.(in Chinese))
[8] 金佳旭，秦志发，刘 磊，等.工业固废–水泥固化腐殖土的力学响应和微观机制[J]. 岩土工程学报，2024，46(11)：2 410–2 419. (JIN Jiaxu，QIN Zhifa，LIU Lei，et al. Mechanical response and micro-mechanism of humus soil solidified by industrial solid waste-cement[J]. Chinese Journal of Geotechnical Engineering，2024，46(11)：2 410–2 419.(in Chinese))
[9] 王东星，许凤丽，泮晓华，等. GGBS-MICP协同固化淤泥质砂土工程特性研究[J]. 岩石力学与工程学报，2025，44(5)：1 349–1 362. (WANG Dongxing，XU Fengli，PAN Xiaohua，et al. Study on the engineering properties of GGBS-MICP synergistic solidification of silty-sandy soil[J]. Chinese Journal of Rock Mechanics and Engineering，2025，44(5)：1 349–1 362.(in Chinese))
[10] 张淼鑫，孙剑飞，张晓东，等. 应用木质素磺酸钙–粉煤灰对寒区碳酸盐渍土力学性能的改良[J]. 东北林业大学学报，2022，50(10)：96–100.(ZHANG Miaoxin，SUN Jianfei，ZHANG Xiaodong，et al. Applying calcium lignosulfonate-fly ash to improve mechanical properties of carbonate stained soil in cold areas[J]. Journal of Northeast Forestry University，2022，50(10)：96–100.(in Chinese))
[11] 魏 丽，柴寿喜，薛美玲. 以抗剪性能与结构损伤评价纤维加筋土的冻融耐久性[J]. 岩石力学与工程学报，2022，41(增2)：3 453–3 463. (WEI Li，CHAI Shouxi，XUE Meiling. Evaluation of freeze-thaw durability of fiber reinforced soil by shear performances and structural damage[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(Supp.2)：3 453–3 463.(in Chinese))
[12] 陈 诚，郭 伟，任宇晓. 冻融循环条件下木质素纤维改良土性质研究及微观分析[J]. 岩土工程学报，2020，42(增2)：135–140.(CHEN Cheng，GUO Wei，REN Xiaoyu. Properties and microscopic analysis of lignin fiber-reinforced soils under freeze–thaw cycles[J]. Chinese Journal of Geotechnical Engineering，2020，42(Supp.2)：135–140.(in Chinese))
[13] 谢嘉豪，李建东，王 旭，等. 冻融循环作用对F1加固黄土强度与微观结构的影响研究[J]. 防灾减灾工程学报，2023，43(6)：1 445–1 453. (XIE Jiahao，LI Jiandong，WANG Xu，et al. Effects of freeze?thaw cycles on the strength and microstructure of f1?solidified loess[J]. Journal of Disaster Prevention and Mitigation Engineering，2023，43(6)：1 445–1 453.(in Chinese))
[14] 李新明，张浩扬，武 迪，等. 石灰–偏高岭土改良遗址土强度劣化特性的冻融循环效应[J]. 岩土力学，2023，44(6)：1 593–1 603. (LI Xinming，ZHANG Haoyang，WU Di，et al. Strength deterioration characteristics of lime-metakaolin improved earthen site soil under freeze-thaw cycles[J]. Rock and Soil Mechanics，2023，44(6)：1 593–1 603.(in Chinese))
[15] CHEN，Z F，CHEN H E，MA W L. Study on the changing rules of silty Clay?s pore structure under freeze-thaw cycles[J]. Journal of Engineering，2019，2019：7493872.
[16] 齐吉琳，张建明，朱元林. 冻融作用对土结构性影响的土力学意义[J]. 岩石力学与工程学报，2003，22(增2)：2 690–2 694.(QI Jiling，ZHANG Jianming，ZHU Yuanlin. Influence of freezing- thawing on soil structure and its soil mechanics significance[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(Supp.2)：2 690–2 694.(in Chinese))
[17] 刘 宽，叶万军，景宏君，等. 季冻区黄土微观损伤识别与宏观力学响应研究[J]. 岩土工程学报，2021，43(增1)：192–197.(LIU Kuan，YE Wanjun，JING Hongjun，et al. Microscopic damage identification and macroscopic mechanical response of loess in seasonal frozen areas[J]. Chinese Journal of Geotechnical Engineering，2021，43(Supp.1)：192–197.(in Chinese))
[18] FAN W H，YANG P，WANG S F，et al. Freeze-thaw effects on pore structure of clay by 3D X-ray computed tomography and mercury intrusion porosimetry[J]. Cold Regions Science and Technology，2024，225：104276.
[19] 王天亮，刘建坤，田亚护. 冻融作用下水泥及石灰改良土静力特性研究[J]. 岩土力学，2011，32(1)：193–198.(WANG Tianliang，LIU Jiankun，TIAN Yahu，Static properties of cement and lime-modified soil subjected to freeze-thaw cycles[J]. Rock and Soil Mechanics，2011，32(01)：193–198.(in Chinese))
[20] 汤怡新，刘汉龙，朱 伟. 水泥固化土工程特性试验研究[J]. 岩土工程学报，2000，22(5)：549–554.(TANG Yixin，LIU Hanlong，ZHU Wei. Study on engineering properties of cement-stabilized soil[J]. Chinese Journal of Geotechnical Engineering，2000，22(5)：549–554.(in Chinese))
[21] 马冬冬，马芹永，黄 坤，等. 基于NMR的地聚合物水泥土孔隙结构与动态力学特性研究[J]. 岩土工程学报，2021，43(3)：572–578.(MA Dongdong，MA Qinyong，HUANG Kun，et al. Pore structure and dynamic mechanical properties of geopolymer cement soil based on nuclear magnetic resonance technique[J]. Chinese Journal of Geotechnical Engineering，2021，43(3)：572–578.(in Chinese))
[22] 叶万军，李长清，杨更社，等.冻融环境下黄土体结构损伤的尺度效应[J]. 岩土力学，2018，39(7)：2 336–2 343.(YE Wanjun，LI Changqing，YANG Gengshe，et al. Scale effects of damage to loess structure under freezing and thawing conditions[J]. Rock and Soil Mechanics，2018，39(7)：2 336–2 343.(in Chinese))
[23] XU F，WEI H，QIAN W CX，et al. Composite alkaline activator on cemented soil：Multiple tests and mechanism analyses[J]. Construction and Building Materials，2018，188：433–443.
2026, Vol. 45 
