Moisture migration law and water immersion deformation characteristics of loess high-fill foundations
YANG Xiaohui1, 2, PAN Guojie1, 2, GUO Nan1, 2, HUANG Xuefeng1, 3, CHEN Pengshan1, 2
(1. School of Civil and Hydraulic Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 3. Department of Military Facilities Engineering, Engineering University of
the Joint Logistics Support Force, Chongqing 401311, China)
Abstract：To investigate the moisture migration and immersion-induced deformation characteristics of loess high-fill foundations, a field immersion test was conducted on a layered compacted high-fill project in Lanzhou. Over a period of 364 d, the volumetric water content, surface settlement deformation, and crack development around the test pit were monitored. This study analyzed the moisture migration patterns, variations in vertical and horizontal permeability coefficients, and the wetting deformation characteristics of the fill foundation. The results indicate the following: (1) During immersion, daily water consumption exhibited distinct stage-wise characteristics. The upper section of the fill foundation can enhance anti-seepage effectiveness by employing loess mixed fill and increasing compaction. (2) Evaporation must be accounted for in field immersion tests. Daily infiltration stabilized at 2.5–3.0 m3/d, with evaporation constituting approximately 2/3 to 1/2 of the daily water consumption. (3) Full development of wetting deformation requires multiple cycles. As fill depth increases, the onset of deep soil wetting is delayed, resulting in long-term post-construction settlement. (4) The vertical permeability rate decreases with increasing fill depth, while the horizontal permeability rate remains consistent, leading to an oblate elliptical moisture diffusion pattern. (5) The “boundary effect” of immersion deformation in fill foundations differs significantly from that in undisturbed loess foundations. For fill foundations located near water sources, a minimum safety distance of 10 m should be maintained between structures and the water source. (6) During the immersion process of the fill foundation, the surface settlement rate in the last month should not exceed 2.5 mm/d as the criterion for ceasing immersion. These findings provide a scientific basis for the treatment of fill foundations and the mitigation of wetting deformation issues in loess regions.
[1] 朱才辉，李 宁. 降雨对沟谷状黄土高填方地基增湿影响研究[J]. 岩土工程学报，2020，42(5)：845–854.(ZHU Caihui，LI Ning. Influence of rainfall on moisture increase of valley-shaped high loess fill foundation[J]. Chinese Journal of Geotechnical Engineering，2020，42(5)：845–854.(in Chinese))
[2] 杨校辉，钱 豹，郭 楠，等. 某黄土填方地基不均匀沉降影响因素及长期变形规律研究[J]. 岩土工程学报，2022，44(增1)：207–212.(YANG Xiaohui，QIAN Bao，GUO Nan，et al. Influencing factors of uneven settlement and long-term deformation law of a loess fill foundation[J]. Chinese Journal of Geotechnical Engineering，2022，44(Supp.1)：207–212.(in Chinese))
[3] 姚志华，陈正汉，黄雪峰，等. 非饱和原状和重塑Q3黄土渗水特性研究[J]. 岩土工程学报，2012，34(6)：1 020–1 027.(YAO Zhihua，CHEN Zhenghan，HUANG Xuefeng，et al. Seepage characteristics of unsaturated intact and remolded Q3 loess[J]. Chinese Journal of Geotechnical Engineering，2012，34(6)：1 020–1 027.(in Chinese))
[4] 胡海军，王 晨，吕彤阳，等. 一维载荷浸水下重塑黄土的水分入渗和增湿变形模型及试验验证[J]. 岩石力学与工程学报，2022，41(5)：1 020–1 030.(HU Haijun，WANG Chen，LYU Tongyang，et al. Water infiltration and wetting deformation model of remolded loess under one-dimensional loading and immersion and its experimental verification[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(5)：1 020–1 030.(in Chinese))
[5] 姚志华，黄雪峰，陈正汉，等. 自重湿陷性黄土的水气运移及力学变形特征[M]. 北京：人民交通出版社，2017：20–31(YAO Zhihua，HUANG Xuefeng，CHEN Zhenghan，et al. Water-air transport and mechanical deformation characteristics of self-weight collapsible loess[M]. Beijing：China Communications Press，2017：20–31.(in Chinese))
[6] 黄雪峰，陈正汉，哈 双，等. 大厚度自重湿陷性黄土场地湿陷变形特征的大型现场浸水试验研究[J]. 岩土工程学报，2006，28(3)：382–389.(HUANG Xuefeng，CHEN Zhenghan，HA Shuang，et al. Large-scale field immersion test on collapsibility deformation characteristics of self-weight collapsible loess site with large thickness[J]. Chinese Journal of Geotechnical Engineering，2006，28(3)：382–389.(in Chinese))
[7] 王小军，屈耀辉，魏永梁，等. 郑西客运专线湿陷性黄土区试验路堤的沉降观测与预测研究[J]. 岩土力学，2010，31(增1)：220–231. (WANG Xiaojun，QU Yaohui，WEI Yongliang，et al. Settlement observation and prediction of test embankment in collapsible loess area of Zhengzhou—Xi?an passenger dedicated line[J]. Rock and Soil Mechanics，2010，31(Supp.1)：220–231.(in Chinese))
[8] 马 闫，王家鼎，彭淑君，等. 大厚度黄土自重湿陷性场地浸水湿陷变形特征研究[J]. 岩土工程学报，2014，36(3)：537–546.(MA Yan，WANG Jiading，PENG Shujun，et al. Research on characteristics of immersion collapsibility deformation of self-weight collapsible loess site with large thickness[J]. Chinese Journal of Geotechnical Engineering，2014，36(3)：537–546. (in Chinese))
[9] LV Y Q，DENG L S，FAN W. Loess collapsibility characteristics of railway engineering sites using large-scale trial immersion pit experiments[J]. Bulletin of Engineering Geology and the Environment，2021，80(4)：3 271–3 291.
[10] 杨校辉，黄雪峰，朱彦鹏，等. 大厚度自重湿陷性黄土地基处理深度和湿陷性评价试验研究[J]. 岩石力学与工程学报，2014，33(5)：1 063–1 074.(YANG Xiaohui，HUANG Xuefeng，ZHU Yanpeng，et al. Experimental study on treatment depth and collapsibility evaluation of large thickness self-weight collapsible loess foundation[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(5)：1 063–1 074.(in Chinese))
[11] 刘德仁，安政山，徐硕昌，等. 靖远地区大厚度黄土地基浸水湿陷过程及土中竖向应力特征试验研究[J]. 岩土力学，2023，44(1)：268–278.(LIU Deren，AN Zhengshan，XU Shuochang，et al. Experimental study on immersion collapsibility process and vertical stress characteristics of large thickness loess foundation in Jingyuan area[J]. Rock and Soil Mechanics，2023，44(1)：268–278.(in Chinese))
[12] 黄雪峰，杨校辉. 湿陷性黄土现场浸水试验研究进展[J]. 岩土力学，2013，34(增2)：222–228.(HUANG Xuefeng，YANG Xiaohui. Research progress of field immersion tests on collapsible loess[J]. Rock and Soil Mechanics，2013，34(Supp.2)：222–228.(in Chinese))
[13] LI Y，WANG Y，AYDIN A. Loess structure：Evolution and a scale-based classification[J]. Earth-Science Reviews，2024，249(1)：104665.
[14] WEI Y，FAN W，YU B，et al. Investigation of the collapse potential of Malan loess from different regions on the Loess Plateau in terms of pore size distribution and clay distribution form[J]. Acta Geotechnica，2023，18(12)：6 595–6 613.
[15] 蔡国庆，王亚南，周安楠，等. 考虑微观孔隙结构的非饱和土水–力耦合本构模型[J]. 岩土工程学报，2018，40(4)：618–624.(CAI Guoqing，WANG Ya?nan，ZHOU Annan，et al. Hydro-mechanical coupled constitutive model for unsaturated soils considering microstructure of pore space[J]. Chinese Journal of Geotechnical Engineering，2018，40(4)：618–624. (in Chinese))
[16] 甄平福. 黄土高填方场地大型现场浸水试验研究[硕士学位论文][D]. 西安：长安大学，2018.(ZHEN Pingfu. Study on the large area field immersion tests in loess high fill ground[M. S. Thesis][D]. Xi'an：Chang?an University，2018.(in Chinese))
[17] 李 阳，刘 魁，刘双承，等. 黄土高填方场地挖填结合区桩基础浸水试验研究[J]. 工程地质学报，2025，33(2)：794–801.(LI Yang，LIU Kui，LIU Shuangcheng，et al. Immersion test study on pile foundation in excavation-fill interface zone of high loess fill site[J]. Journal of Engineering Geology，2025，33(2)：794–801.(in Chinese))
[18] RAN G，ZHU Y，YANG X，et al. Permeability characteristics of improved loess and prediction method for permeability coefficient[J]. Applied Sciences，2024，14(17)：8 072.
[19] 朱彦鹏，杨校辉，王秀丽，等. 高填方变形无线远程综合监测系统及安装监测方法[P]. 中国：CN201510555457.3.(ZHU Yanpeng，YANG Xiaohui，WANG Xiuli，et al. Wireless remote comprehensive monitoring system and installation monitoring method for high fill deformation[P]. Chinese：CN201510555457.3.(in Chinese))
[20] ZHANG Y，QIAN H，HOU K，et al. Investigating and predicting the temperature effects of permeability for loess[J]. Engineering Geology，2021，285(1)：106050.
[21] 姚志华，黄雪峰，陈正汉，等. 兰州地区大厚度自重湿陷性黄土场地浸水试验综合观测研究[J]. 岩土工程学报，2012，34(1)：65–74. (YAO Zhihua，HUANG Xuefeng，CHEN Zhenghan，et al. Comprehensive observation and study on field immersion tests of large-thickness self-weight collapsible loess ground in Lanzhou region[J]. Chinese Journal of Geotechnical Engineering，2012，34(1)：65–74.(in Chinese))
[22] 杨校辉，赵子毅，郭 楠，等. 横观各向同性非饱和黄土蠕变特性及沉降预测[J]. 岩土力学，2025，46(5)：1 489–1 500.(YANG Xiaohui，ZHAO Ziyi，GUO Nan，et al. Creep characteristics and settlement prediction of transversely isotropic unsaturated loess[J]. Rock and Soil Mechanics，2025，46(5)：1 489–1 500.(in Chinese))
[23] 郭 楠，陈正汉，杨校辉，等. 各向同性土与横观各向同性土的力学特性和持水特性[J]. 西南交通大学学报，2019，54(6)：1 235–1 243. (GUO Nan，CHEN Zhenghan，YANG Xiaohui，et al. Mechanical properties and water holding characteristics of initially isotropic soils and transversely isotropic soils[J]. Journal of Southwest Jiaotong University，2019，54(6)：1 235–1 243.(in Chinese))
2025, Vol. 44 
