Enhanced vacuum drainage performance of soft soil via freeze-thaw disturbance
ZHANG Hu1, 2*, HU Jintao1, ZHENG Bo3, XING Lijun1, WEN Cheng1, SHI Lihan1, GUO Huanming4
(1. School of Civil Engineering and Transportation, Northeast Forestry University, Harbin, Heilongjiang 150040, China; 2. State Key Laboratory of Cryospheric Science and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China; 3. China Railway Southwest Research Institute Co., Ltd., Chengdu, Sichuan 611731, China; 4. School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730000, China)
Abstract：To address the low drainage efficiency and insufficient consolidation typically encountered during the vacuum preloading of low-permeability soft soil, this study introduces a pre-vacuum freeze-thaw disturbance aimed at enhancing the soil structure and improving drainage performance. Vacuum drainage tests were conducted on specimens subjected to various disturbance modes, with continuous monitoring of the coupled thermal-hydraulic-mechanical responses, settlement evolution, and energy consumption throughout the artificial freeze-thaw and vacuum stages. Post-consolidation measurements of water content and shear strength were also performed. The results indicate that ice crystallization and fissure development during freezing significantly increased soil permeability by approximately 10%-40%. Upon thawing, the newly formed pore channels facilitated accelerated vacuum drainage. During vacuum preloading, the freeze-thaw disturbed specimens exhibited faster water content reduction, more rapid dissipation of pore-water pressure, greater strength enhancement, and larger settlement compared to the undisturbed specimens, indicating a significant improvement in overall consolidation efficiency. Although the disturbed group consumed more total energy, its energy-consumption ratio throughout the process displayed a stage-dependent pattern: an initial sharp rise, a rapid mid-stage decline, and a slight late-stage increase. Notably, the late-stage energy consumption ratio of the disturbed specimens was lower than that of the undisturbed group, demonstrating superior full-cycle energy performance. This study provides a novel technical pathway for achieving efficient dewatering and consolidation of soft soil.
[1] 油新华，徐良平，平 洋，等. 双碳背景下岩土工程绿色建造理念与技术实践[J]. 建筑技术，2022，53(6)：773–776.(YOU Xinhua，XU Liangping，PING Yang，et al. Green construction concept and techniacl practice of geotechnical engineering under background of double carbon[J]. Architecture Technology，2022，53(6)：773–776.(in Chinese))
[2] 孙留存，肖绪文，朱 彤，等. 中国绿色建造：发展理念、主导方向与技术创新[J]. 中国工程科学，2024，26(6)：190–201.(SUN Liucun，XIAO Xuwen，ZHU Tong，et al. Green construction in China：development concept，leading directions，and technological innovation[J]. Strategic Study of CAE，2024，26(6)：190–201.(in Chinese))
[3] 宋许根，王志勇，柏威伟，等. 珠海西部中心城区大面积深厚软土工程特性研究[J]. 岩石力学与工程学报，2019，38(7)：1 434–1 451. (SONG Xugen，WANG Zhiyong，BAI Weiwei，et al. Study on engineering characteristics of large-scale deep soft soil in the central area of western Zhuhai[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(7)：1 434–1 451.(in Chinese))
[4] 郑 刚，张军辉，章定文，等. 地基处理技术现状与发展[J]. 土木工程学报，2024，57(7)：51–70.(ZHENG Gang，ZHANG Junhui，ZAHNG Dingwen，et al. State-of-the-art of ground improvement technologies[J]. China Civil Engineering Journal，2024，57(7)：51–70.(in Chinese))
[5] 周 建，蒋熠诚，朱则铭，等. 电渗加固软土地基界面电阻理论与试验研究[J]. 岩土工程学报，2023，45(10)：1 995–2 003.(ZHOU Jian，JIANG Yicheng，ZHU Zeming，et al. Theoretical and experimental studies on interfacial resistance of electro-osmotic consolidation for soft ground improvement[J]. Chinese Journal of Geotechnical Engineering，2023，45(10)：1 995–2 003.(in Chinese))
[6] 童佳荣，张 曙，李 荣，等. 电动化学加固技术对珠海软土改性的机制研究[J]. 岩土力学，2025，46(增1)：262–270.(TONG Jiarong，ZHANG Shu，LI Rong，et al. Mechanism of electro-chemical stabilization for modifying Zhuhai soft clay[J]. Rock and Soil Mechanics，2025，46(Supp.1)：262–270.(in Chinese))
[7] 吕延栋，朱龙祥，王 旭，等. 电渗–堆载–化学灌浆联合处理淤泥质软土的试验研究[J]. 岩土工程学报，2021，43(增2)：100–103.(LV Yandong，ZHU Longxiang，WANG Xu，et al. Experimental investigation on electro-osmosis-surcharge preloading-chemical grouting for silty soft soils[J]. Chinese Journal of Geotechnical Engineering，2021，43(Supp.2)：100–103.(in Chinese))
[8] 黄鹏华，王柳江，刘斯宏，等. 真空堆载预压联合电渗竖向排水地基非线性固结解析解[J]. 岩石力学与工程学报，2021，40(1)：206–216.(HUANG Penghua，WANG Liujiang，LIU Sihong，et al.Nonlinear analytical solutions for vertical drainage consolidation of foundations under vacuum-surcharge preloading combined with electroosmosis[J]. Chinese Journal of Rock Mechanics andEngineering，2021，40(1)：206–216.(in Chinese))
[9] BAI J T，WANG C，ZHANG M H，et al. A review on drainage of dredged marine soils：Advances and prospects[J]. Marine Georesources and Geotechnology，2025，43(2)：260–270.
[10] 简东升，朱敬平，李笃中，等. 以天然气候进行污泥的冻融处理[J]. 应用基础与工程科学学报，2000，8(4)：370–375.(JIAN Dongsheng，ZHU Jingping，LI Duzhong，et al. Freeze/thaw treatment of sludge via natural climate[J]. Journal of Basic Science and Engineering，2000，8(4)：370–375.(in Chinese))
[11] CHEN L C，CHINA C Y，YEN P S，et al. High-speed sludge freezing[J]. Water Research，2001，35(14)：3 502–3 507.
[12] TUNÇAL T，MUJUMDAR A S. Modern techniques for sludge dewaterability improvement[J]. Drying Technology，2023，41(3)：339–351.
[13] LIU Z，LUO F，HE L Z，et al. Physical conditioning methods for sludge deep dewatering：A critical review[J]. Journal of Environmental Management，2024，360(6)：121207.
[14] 武亚军，何心妍，张旭东，等. 冻融预处理填埋污泥的室内真空脱水试验[J]. 哈尔滨工业大学学报，2021，53(11)：154–161.(WU Yajun，HE Xinyan，ZHANG Xudong，et al. Experimental study on vacuum dehydration of sludge in landfill by freeze-thaw pretreatment[J]. Journal of Harbin Institute of Technology，2021，53(11)：154–161.(in Chinese))
[15] 张云达，徐 杨，武亚军，等. 不同类型排水板对“冻融–真空预压”法原位处理填埋污泥工艺中污泥脱水效果的影响[J]. 环境工程学报，2021，15(11)：3 669–3 676.(ZHANG Yunda，XU Yang，WU Yajun，et al. Comparative test on the effect of freeze-thaw vacuum preloading on landfill sludge under different types of plastic drainage boards[J]. Chinese Journal of Environmental Engineering，2021，15(11)：3 669–3 676.(in Chinese))
[16] XU Y，WU Y J，ZHANG X D，et al. Anti-clogging mechanism of freeze-thaw combined with step vacuum preloading in treating landfill sludge[J]. Environmental Research，2023，218(2)：115059.
[17] 冯双喜，张国庆，李耀旭，等. 冻融–热真空预压法处理超软土地基脱水与加固机制[J]. 铁道科学与工程学报，2026，待刊.(FENG Shuangxi，ZHANG Guoqing，LI Yaoxu，et al. Analysis on the dewatering performance and reinforcement mechanism of ultra-soft soil ground treated by freeze-thaw and thermal consolidation combined vacuum preloading[J]. Journal of Railway Science and Engineering，2026，to be pressed.(in Chinese))
[18] HU J T，ZHANG H，ZHANG S J，et al. Cryostructural characteristics and visual deformation process of soft clay under horizontal freezing condition：Experiment evidence[J]. Engineering Geology，2025，357(10)：108321.
[19] ZHANG X D，YE P，FUJII M，et al. The application of freeze-thaw cycle treatment on landfill sludge：Impact on physicochemical properties and physical-mechanical characteristics[J]. Journal of Cleaner Production，2024，468(8)：143106.
[20] 刘永超，张天雨，解邦龙，等. 不同深度天津原状软土的物理力学特性试验研究[J]. 土木工程学报，2023，56(增2)：122–131.(LIU Yongchao，ZHANG Tianyu，XIE Banglong，et al. Experimental study on properties of undisturbed soft soil at different depths in Tianjin[J]. China Civil Engineering Journal，2023，56(Supp.2)：122–131.(in Chinese))
[21] 刘 杰，周耀福，李 宾，等. 冻融循环条件下伊犁黄土渗透特性研究[J]. 水文地质工程地质，2025，待刊.(LIU Jie，ZHOU Yaofu，LI Bin，et al. Study on permeability characteristics of Yili loess under freeze-thaw cycles[J]. Hydrogeology and Engineering Geology，2025，to be pressed.(in Chinese))
[22] 王智超，王炜超，彭慧良，等. 复杂应力路径下海相结构性软土力学特征试验[J]. 铁道科学与工程学报，2023，20(8)：2 868–2 877. (WANG Zhichao，WANG Weichao，PENG Huiliang，et al. Mechanical characteristic test of structural marine soft clay under complex stress paths[J]. Journal of Railway Science and Engineering，2023，20(8)：2 868–2 877.(in Chinese))
[23] ALMEIDAl M，MARQUES M，RICCIO M，et al. Ground improvement techniques applied to very soft clays：state of knowledge and recent advances[J]. Soils and Rocks，2023，46(1)：e2023008222.
[24] 唐丽云，李屹恒，于永堂，等. 冻融作用下土石混合体-混凝土界面强度劣化、孔隙结构演化及颗粒运移研究[J]. 冰川冻土，2023，45(3)：1 047–1 062.(TANG Liyun，LI Yiheng，YU Yongtang，et al. Study on strength deterioration，pore structure evolution and particle migration of interface between soil-rock mixture and concrete under freeze-thaw action[J]. Journal of Glaciology and Geocryology，2023，45(3)：1 047–1 062.(in Chinese))
[25] 张 虎，胡金涛，郑 波，等. 水平冻结下软黏土水热力响应及冷生构造研究[J]. 岩土工程学报，2025，47(8)：1 681–1 689.(ZHANG Hu，HU Jintao，ZHENG Bo，et al. Hydrothermal，mechanical responses and cryostructure of soft clay under horizontal freezing[J]. Chinese Journal of Geotechnical Engineering，2025，47(8)：1 681–1 689.(in Chinese))
[26] 张建新，马昌虎，郎瑞卿，等. 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(增1)：3 801–3 811.(ZHANG Jianxin，MA Changhu，LANG Ruiqing，et al. Experimental study on mechanical properties and microstructure of muddy soil under different freeze-thaw modes[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(Supp.1)：3 801–3 811.(in Chinese))
[27] 王柳江，陈强强，刘斯宏，等. 水平排水板真空预压联合电渗处理软黏土模型试验研究[J]. 岩石力学与工程学报，2020，39(增2)：3 516–3 525.(WANG Liujiang，CHEN Qiangqiang，LIU Sihong，et al. Model test on treatment of soft clay under combined vacuum preloading with electro-osmosis using prefabricated horizontal drain[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(Supp.2)：3 516–3 525.(in Chinese))
2026, Vol. 45 
