广布于黄土高原地区的黄土大部分处于季冻区，受其赋存气候条件影响，冻融环境下浅层和深部黄土受含水状态、荷载边界条件等多重因素控制，显著影响黄土冻结温度和变形，但现有研究尚有不足。

本文以陕西泾阳黄土为研究对象，开展冻融循环过程中不同含水状态（w=11.5%、14.5%、17.5%、20.5%和23.5%）、荷载边界条件（P=50kPa、100kPa、200kPa和400kPa）重塑黄土冻结温度和一维变形的试验研究；基于自研的黄土三维变形试验装置，分析试验装置开展冻融过程重塑黄土三维变形和冻结力测试的可行性，探讨柔性薄膜压力传感器不同约束方式以及压力传感器、应变片测试位置对试验结果的影响，继而进行不同含水状态（w=11.5%、14.5%、17.5%和20.5%）重塑黄土三维变形和冻结力试验研究，论文取得的成果如下：

（1）冻融过程中重塑黄土冻结温度随含水率的增大先升高后趋于稳定；随荷载增大略有降低；随冻融循环次数增加而快速降低，并且当重塑黄土含水率低于塑限含水率时，冻结温度随含水率的增大而强烈波动，但当重塑黄土含水率大于塑限含水率时，冻结温度随含水率的增大而轻微降低；

（2）冻融过程中随含水率增大，重塑黄土变形由冻缩融胀转变为冻胀融沉，冻缩、冻胀随含水率的增大而增大；随荷载增大，重塑黄土冻缩逐渐增大、冻胀快速减小，其起始冻胀含水率先增大后趋于稳定，约为塑限含水率的1.06～1.11倍；随冻融循环次数增加，重塑黄土冻缩、冻胀均减小。不同荷载边界条件下，重塑黄土起始冻胀含水率随冻融循环次数增加呈先减小后稳定趋势，但始终大于塑限含水率；

（3）自研黄土三维变形试验装置可用于冻融过程黄土三维变形和冻结力测试；冻融过程中重塑黄土径向变形自上而下逐渐减小，整体变形呈不均匀性；不同含水状态下重塑黄土三维变形以冻缩融胀为主，冻融过程中冻结力的变化与其变形同步，随含水率增大，重塑黄土三维变形逐渐增大，当含水率大于一定值时，其径向发生短暂的冻胀变形，且随含水率的增大而增大。

冻融环境下含水状态、荷载边界条件对重塑黄土冻结温度和变形影响的试验研究，可进一步深化对黄土高原地区季冻区和人工冻结工程中黄土冻结温度和变形的认识，丰富自然冻融气候环境和人工冻结场景黄土温度场和变形场的研究成果，为工程实践提供一定的理论依据和技术支撑，研究成果具有一定的科学意义和工程应用价值。

Most of loess widely distributed in the Loess Plateau is located in the seasonal frozen regions. The shallow loess and deep loess in the freeze-thaw environment are controlled by water content and load, which significantly affects the freezing point and deformation of the loess. However, existing research is still insufficient.

In this paper, the loess was collected from Jingyang County, Shaanxi Province. Experimental research on freezing point and one-dimensional deformation of loess was conducted during freezing-thawing cycles under different water content (w=11.5%,14.5%,17.5%,20.5% and 23.5%) and load (P=50kPa,100kPa,200kPa and 400kPa); Based on the self-developed loess three-dimensional deformation test device, the feasibility of the test device to carry out the three-dimensional deformation and freezing force test of loess during the freezing and thawing process was analyzed, and the influence of different restraint methods of tactile pressure sensor and the installation positions of tactile pressure sensor and resistance strain gauge on the test results was discussed. Experimental study on three-dimensional deformation and freezing force of loess in different water content (w=11.5%, 14.5%, 17.5% and 20.5%) based on the test device was conducted. The results of the paper were as follows:

(1) During the freezing and thawing process, the freezing point of loess increased first and then tended to be stable with the increase of water content; the freezing point decreased slightly with the increase of load; the freezing point decreased rapidly with the increase of freezing-thawing cycles, and at this time, the freezing point fluctuated strongly with the increase of water content when the water content of loess was lower than the plastic limit water content, but when the water content of loess was greater than the plastic limit moisture content, the freezing point decreased slightly with the increase of water content;

(2) During the freezing and thawing process, with the increase of water content, the deformation of loess changed from frost shrink and thermal bulge to frost heave and thaw settlement, and the frost shrink and frost heave increased with the increase of water content; As the load increased, the frost shrink deformation increased and the frost heave deformation decreased rapidly of loess, and the initial frost heave water content increased first and then tended to be stable, which was about 1.06 to 1.11 times of the plastic limit water content; The frost shrink deformation and frost heave deformation of loess decreased with the increase of freeze-thaw cycles. The initial frost heave water content of loess decreased first and then stabilized with the increase of freezing-thawing cycles under different load boundary conditions, but was always higher than the plastic limit water content;

(3) The self-developed loess three-dimensional deformation test device could be used for the three-dimensional deformation and freezing force test of loess; The radial deformation of loess gradually decreased from top to bottom during the freezing and thawing process, so the overall deformation of loess was unevenly; The three-dimensional deformation of the loess under different water content was dominated by frost shrink and thermal bulge, and the change of freezing force was synchronized with its deformation during the freezing and thawing process. The three-dimensional deformation of loess increased gradually with the increase of water content, and short-term frost heave deformation occurred in the loess radial direction when the water content was higher than a certain value, and the frost heave deformation also increased with the increase of water content.

The experimental research on the influence of water content and load on the freezing point and deformation of loess in the freeze-thaw environment could further deepen the understanding of the freezing point and deformation of loess in the seasonal frozen regions of the Loess Plateau, enrich the research results of loess temperature field and deformation field in natural freeze-thaw climate environment and artificial freezing scene, and provide a certain theoretical basis and technical support for engineering practice. The research results had certain scientific significance and engineering application value.

[1]王念秦,姚勇. 季节冻土区冻融期黄土滑坡基本特征与机理[J]. 防灾减灾工程学报,2008,28(2):163-166.

[2]Grechishchev S E, Instanes A, Sheshin J B, et al. Laboratory investigation of the freezing point of oil-polluted soils[J]. Cold Regions Science and Technology,2001,32:183-189.

[3]Ming F, Chen L, Li D Q,et al. Investigation into freezing point depression in soil caused by NaCl solution[J]. Water,2020,12:1-15.

[4]Xin Q M, Su Y J, Cao Y, et al. Experimental and modeling investigation of freezing characteristic curve of silty clay using TDR[J]. Cold Regions Science and Technology,2023,205:103715.

[5]刘振压, 刘建坤, 李旭, 等. 非饱和粉质黏土冻结温度和冻结变形特性试验研究[J]. 岩土工程学报,2017,39(8):1381-1387.

[6]周家作,谭龙,韦昌富,等. 土的冻结温度与过冷温度试验研究[J]. 岩土力学,2015,36(3):777-785.

[7]路建国,张明义,张熙胤,等. 冻融过程中未冻水含量及冻结温度的试验研究[J]. 岩石力学与工程学报,2017,36(7):1803-1812.

[8]吴刚,邴慧,卜东升. 盐渍土与盐溶液冻结温度关系的试验研究[J]. 冰川冻土,2019,41(3):615-628.

[9]任亚军,张卫兵. 单向冻结条件下硫酸钠盐渍土的冻结温度试验研究[J]. 长江科学院院报,2023,40(3):124-130.

[10]Han Y, Wang Q, Kong Y Y, et al. Experiments on the initial freezing point of dispersive saline soil[J]. Catena,2018,171:681-690.

[11]Kozlowski T. Soil freezing point as obtained on melting[J]. Cold Regions Science and Technology,2004,38:93-101.

[12]李毅,崔广心,吕恒林. 有压条件下湿粘土结冰温度的研究[J]. 冰川冻土,1996，18(1):43-46.

[13]崔广心,杨维好,李毅. 受载荷的湿土结冰温度变化规律的研究[J]. 冰川冻土,1997,19(4):321-327.

[14]Zhang L H, Yang C S, Wang D Y, et al. Freezing point depression of soil water depending on its non-uniform nature in pore water pressure[J]. Geoderma,2022,412:115724.

[15]Fabbri A, Fen C, Coussy O. Dielectric capacity, liquid water content, and pore structure of thawing-freezing materials[J]. Cold Regions Science and Technology,2006,44:52-66.

[16]Guan H, Wang S H, Wang Y T, et al. Experimental study on freezing point of deep clay under high external load conditions[J]. Cold Regions Science and Technology,2023,205:103696.

[17]Kozlowski T. A simple method of obtaining the soil freezing point depression, the unfrozen water content and the pore size distribution curves from the DSC peak maximum temperature[J]. Cold Regions Science and Technology,2016,122:18-25.

[18]Ohkubo T, Ibaraki M, Tachi Y, et al. Pore distribution of water-saturated compacted clay using NMR relaxometry and freezing temperature depression; effects of density and salt concentration[J]. Applied Clay Science,2016,123:148-155.

[19]Chai M T, Zhang J M, Zhang H, et al. A method for calculating unfrozen water content of silty clay with consideration of freezing point[J]. Applied Clay Science,2018,161:474-481.

[20]Wang C, Lai Y M, Zhang M Y. Estimating soil freezing characteristic curve based on pore-size distribution[J]. Applied Thermal Engineering,2017,124:1049-1060.

[21]Bai R Q, Lai Y M, Zhang M Y, et al. Theory and Application of a novel soil freezing characteristic curve[J]. Applied Thermal Engineering,2017,129:1106-1114.

[22]Wan X S, Yang Z H. Pore water freezing characteristic in saline soils based on pore size distribution[J]. Cold Regions Science and Technology,2020,173:103030.

[23]王秦泽. 冻融作用下含盐黄土的冻结温度研究[D]. 西安:西安理工大学,2020.

[24]He Y Y, Xu Y, Lv Y, et al. Characterization of unfrozen water in highly organic turfy soil during freeze-thaw by nuclear magnetic resonance[J]. Engineering Geology, 2023, 312: 106937.

[25]Wang S H, Zhou X G, Wang S, et al. Freezing point of sodium sulfate loess in check dams after freeze-thaw[J]. Cold Regions Science and Technology,2023,205:103719.

[26]Zhang X Y, Zhang M Y, Pei W S, et al. Experimental study of the hydro-thermal characteristics and frost heave behavior of a saturated silt within a closed freezing system[J]. Applied Thermal Engineering,2018,129:1447-1454.

[27]Gao J Q, Lai Y M, Zhang M Y, et al. Experimental study on the water-heat-vapor behavior in a freezing coarse-grained soil[J]. Applied Thermal Engineering,2018,128:956-965.

[28]荣广秋,王淼,孟上九,等. 季冻区典型土类冻胀特性试验研究[J]. 自然灾害学报,2020,29(2):44-53.

[29]应赛,周凤玺,文桃,等. 硫酸盐渍土降温过程中的盐胀与冻胀特性[J]. 长江科学院院报,2021,38(6):116-122.

[30]Zhou J Z, Pei W S, Zhang X Y, et al. An easy method for assessing frost susceptibility of soils: the freezing ring test[J]. Acta Geotechnica,2022,17:5691-5707.

[31]Ming F, Li D Q. A model of migration potential for moisture migration during soil freezing[J]. Cold Regions Science and Technology,2016,124:87-94.

[32]Sheng D, Zhang F N, Cheng G. A potential new frost heave mechanism in high-speed railway embankments[J]. Geotechnique,2014, 64(2):144-154.

[33]Akagawa S, Hori M, Sugawara J. Frost heaving in ballast railway tracks[J]. Transportation Geotechnics and Geoecology,2017,189:547-553.

[34]Zhang S, Teng J, He Z, et al. Canopy effect caused by vapour transfer in covered freezing soils[J]. Geotechnique,2016,66(11):927-940.

[35]Daryl F, Dagesse. Freezing-induced bulk soil volume changes[J]. Canadian Journal of Soil Science,2011, 90(3):389-401.

[36]Lu Y, Liu S H, Eduardo A, et al. Volume changes and mechanical degradation of a compacted expansive soil under freeze-thaw cycles[J]. Cold Regions Science and Technology,2019,157:206-214.

[37]马巍,王大雁. 中国冻土力学研究50a回顾与展望[J]. 岩土工程学报,2012,34(4):625-640.

[38]尹传军. 季冻区路基土冻胀特性及评价指标体系研究[D]. 哈尔滨:东北林业大学,2014.

[39]王宁,王清,霍珍生,等. 盐分与压实度对盐渍土起始冻胀含水率的影响[J]. 工程地质学报,2016,24(5):951-958.

[40]Zhou G Q, Zhou Y, Hu K, et al. Separate-ice frost heave model for one-dimensional soil freezing process[J]. Acta Geotechnica,2018,13:207-217.

[41]Liu Z Y, Liu J K, Li X, et al. Experimental study on the volume and strength change of an unsaturated silty clay upon freezing[J]. Cold Regions Science and Technology,2019,157:1-12.

[42]Bai R Q, Lai Y M, Pei W S, et al. Investigation on frost heave of saturated-unsaturated soils[J]. Acta Geotechnica,2020,15:3295-3306.

[43]Teng J D, Liu J L, Zhang S, et al. Modelling frost heave in unsaturated coarse-grained soils[J]. Acta Geotechnica,2020,15:3307-3320.

[44]Wang T L, Zhang Y Z, Shu Y, et al. Liquid water-vapour migration tracing and characteristics of coarse-grained soil under high-speed railway train loading in cold regions[J]. Cold Regions Science and Technology,2021,187:103283.

[45]王铁行,赵再昆,金鑫,等. 考虑荷载影响的黄土冻胀特性研究[J]. 冰川冻土,2020,42(4):1249-1255.

[46]Huang L, Sheng Y, Wu J C, et al. Experimental study on frost heaving behavior of soil under different loading paths[J]. Cold Regions Science and Technology,2020,169:102905.

[47]Zhang X Y, Zhang M Y, Lu J G, et al. Effect of hydro-thermal behavior on the frost heave of a saturated silty clay under different applied pressures[J]. Applied Thermal Engineering,2017,117:462-467.

[48]Konrad J M, Morgenstern N R. Effects of applied pressure on freezing soils[J]. Canadian Geotechnical Journal,1982,19(4):494-505.

[49]Qi J L, Wang F Y, Peng L Y, et al. Model test on the development of thermal regime and frost heave of a gravelly soil under seepage during artificial freezing[J]. Cold Regions Science and Technology,2022,196:103495.

[50]Ji Y K, Zhou G Q, Zhao X D, et al. On the frost heaving-induced pressure response and its dropping power-law behaviors of freezing soils under various restraints[J]. Cold Regions Science and Technology,2017,142:25-33.

[51]Lai Y M, Pei W S, Zhang M Y, et al. Study on theory model of hydro-thermal-mechanical interaction process in saturated freezing silty soil[J]. International Journal of Heat and Mass Transfer,2014,78:805-819.

[52]黄永庭,马巍,何鹏飞,等. 不同荷载条件下冻土融化沉降过程试验研究[J]. 冰川冻土,2021,43(1):184-194.

[53]Li T G, Kong L W, Guo A G. The deformation and microstructure characteristics of expansive soil under freeze-thaw cycles with loads[J]. Cold Regions Science and Technology,2021,192:103393.

[54]张晋勋,宋永威,杨昊,等. 荷载及细粒土含量对饱和砂卵石冻胀融沉影响研究[J]. 岩土力学,2022,43(S1):213-221.

[55]胡坤,朱春鹏,王小平. 上覆荷载作用下末透镜体演变规律试验[J]. 煤炭学报,2016,41(S2):393-399.

[56]Rajaei P, Baladi G. Frost heave: A semi-empirical model based on field data[J]. Journal of Cold Regions Engineering, 2015:382-393.

[57]Zheng H, Kanie S J, Niu F J, et al. Application of practical one-dimensional frost heave estimation method in two-dimensional situation[J]. Soils and Foundations,2016,56(5):904-914.

[58]Zhang H, Zhang J M, Zhang Z L, et al. A consolidation model for estimating the settlement of warm permafrost[J]. Computers and Geotechnics,2016,76:43-50.

[59]Fan W H, Yang Z H, Yang P. A model for evaluating settlement of clay subjected to freeze-thaw under overburden pressure[J]. Cold Regions Science and Technology,2020,173:102996.

[60]王天亮,岳祖润. 细粒含量对粗粒土冻胀特性影响的试验研究[J]. 岩土力学,2013,34(2):359-364.

[61]Zhang S S, Zhang J S, Gui Y L, et al. Deformation properties of coarse-grained sulfate saline soil under the freeze-thaw-precipitation cycle[J]. Cold Regions Science and Technology,2020,177:10321.

[62]Wu Y J, Zhai E C, Zhang X D, et al. A study on frost heave and thaw settlement of soil subjected to cyclic freeze-thaw conditions based on hydro-thermal-mechanical coupling analysis[J]. Cold Regions Science and Technology,2021,188:103296.

[63]Traore L B, Rojat F, Fabbri A, et al. Experimental study of strain-temperature behavior of earthen materials under freezing-thawing cycles[J]. Cold Regions Science and Technology,2023,205:103685.

[64]张莲海,马巍,杨成松. 冻融循环过程中土体的孔隙水压力测试研究[J]. 岩土力学,2015,36(7):1856-1864.

[65]GB/T50123-2019, 土工试验方法标准[S]. 北京:中国技术出版社，2019.

[66]GB/50007-2011, 建筑地基基础设计规范[S]. 北京:中国建筑工业出版社，2011.

[67]刘开源,许成顺,贾科敏,等. 薄膜压力传感器(FSR)曲面土压力测量研究[J]. 岩土工程学报,2020,42(3):584-591.

[68]周永毅,张建经,闫世杰,等. 土体冻融特性试验研究现状与思考[J]. 岩石力学与工程学报,2022,41(6):1267-1284.

[69]邴慧,马巍. 盐渍土冻结温度的试验研究[J]. 冰川冻土,2011,33(5):1106-1113.

[70]刘宗超. 湿土冻结温度及其测定[J]. 中国矿业学院学报,1986,15(3):24-31.

[71]尚飞,杨成松,张莲海,等. 黏土颗粒扩散双电层影响因素分析[J]. 冰川冻土,2022,44(2):495-505.

[72]李艳,常晓敏,窦银科,等. 基于超声波的淡水冰力学性能参数研究[J]. 中国测试,2019,45(3):36-40.

[73]张永安,应赛,文桃,等. 冻结过程中单孔冰结晶变形机制研究[J]. 冰川冻土,2022,44(5):1429-1439.

[74]何浩松,腾继东,张升,等. 试论冻害敏感性的合理性[J]. 岩土工程学报,2022,44(2):224-234.

[75]羊晔,刘松玉,邓永锋,等. 土工格栅受力状况的测试新技术[J]. 岩土工程学报,2009,31(7):1133-1137.

[76]刘德俊,浦海,沙子恒,等. 冻融循环条件下砂岩动态拉伸力学特性试验研究[J]. 煤炭科学技术,2022,50(8):60-67.

[77]刘允芳,尹健民,刘元坤. 空心包体式钻孔三向应变计测试技术探讨[J]. 岩土工程学报,2011,33(2):291-296.

[78]裴向军,蒙明辉,袁进科,等. 干燥及饱水状态下裂隙岩石冻融特征研究[J]. 岩土力学,2017,38(7):1999-2006.

[79]朱谭谭,李昂,黄达,等. 应力-冻融耦合作用下砂岩变形与损伤特征研究[J]. 岩石力学与工程学报,2023,42(2):342-351.

[80]廖波,周檀君,季雨坤. 薄膜式土压力分布传感器研发及试验研究[J]. 传感技术学报,2018,31(1):19-24.

[81]Karim K, Anthony K L. Effect of soil particle size on the accuracy of tactile pressure sensors[J]. Journal of Geotechnical and Geoenvironmental Engineering,2022,148(10):06022008.

[82]张紫涛,徐添华,徐韵,等. 薄膜压力传感器在土工试验中的适用性初探[J]. 岩土工程学报,2017,39(S1):209-213.

[83]Lassana B T, Claudiane O P, Antonin F, et al. Experimental assessment of freezing-thawing resistance of rammed earth buildings[J]. Construction and Building Materials,2021,274:121917.

[84]Lu X F, Zhang F, Qin W J, et al. Experimental investigation on frost heave characteristics of saturated clay soil under different stress levels and temperature gradients[J]. Cold Regions Science and Technology,2021,192:103379.

[85]Muszynski M R, Olson S M, Hashash Y M A, et al. Earth pressure measurements using tactile pressure sensors in a saturated sand during static and dynamic centrifuge testing[J]. Geotechnical Testing Journal,2016,39(3):371-390.

[86]Keykhosropour L, Lemnitzer A, Star L, et al. Implementation of soil pressure sensors in large-scale soil-structure interaction studies[J]. Geotechnical Testing Journal,2018,41(4):730-746.

[87]芮瑞,吴端正,胡港,等. 模型试验中模式土压力盒标定及其应用[J]. 岩土工程学报,2016,38(5):837-845.

[88]Wang T F, Qu S J, Liu J K, et al. Frost jacking of piles in seasonally and perennially frozen ground[J]. Cold Regions Science and Technology,2022,203:103662.

[89]Lu J G, Zhang M Y, Zhang X Y, et al. Experimental study on the freezing-thawing deformation of a silty clay. Cold Regions Science and Technology,2018,151:19-27.

[90]杨高升,姚晓亮,周攀峰,等. 冻土试验低温恒温箱温度均匀性试验研究[J]. 中国测试,2017,43(9):134-138.