陕北黄土地区位于季节性冻土区域内，土体的物理力学性质在冻融循环作用下会发生劣化行为，这是导致黄土路堑边坡出现冻融病害现象的重要原因之一。因此，论文以陕北黄土路堑边坡的冻融病害问题为切入点，通过对不同冻融循环次数下的陕北重塑黄土开展物理力学特性试验，获得了土体基本物理参数、细观孔隙结构和抗剪强度指标的变化规律，从而对陕北黄土路堑边坡的冻融病害影响因子及其致灾机理进行了探讨。

通过开展现场调研和现场试验，初步掌握了研究区域内黄土的赋存环境特征和粒径分布特征，同时将黄土路堑边坡的冻融病害现象归纳为人工开挖边坡的冻融剥落破坏和天然边坡的浅层冻融失稳这两种类型，其中冻融剥落破坏又可以分为表皮状、层状、碎块状、混合状这四种冻融剥落形式；以陕北不同地区的重塑黄土为研究对象，开展不同冻融循环次数下的物理力学特性试验，发现试样孔隙比在急剧增大后增幅逐步降低，初始孔隙结构主要以微、小孔隙为主，并在冻融过程中处于一个动态变化的过程，黏聚力和内摩擦角在冻融过程中先显著降低再逐渐趋于稳定，其应力-应变曲线会随围压的增大由弱软化型向弱硬化型过渡，同时还构建了等围压三轴应力状态下陕北黄土的冻融损伤模型，发现当土体达到相同损伤程度时，土体的应变会随围压的升高而变大，其冻融损伤速率随冻融循环次数的增大而逐渐减小；经过对陕北黄土路堑边坡的冻融病害发生机理进行探讨，最终认为土体在冻融过程中所产生的宏观裂纹相互贯通和土体颗粒冻融崩解后脱离坡体是人工开挖边坡发生冻融剥落破坏的主要原因，而天然边坡发生浅层冻融失稳则是因为水分在入渗过程中会沿冻融交界面改变迁移方向，层间胶结物发生水解导致交界面土体的抗剪强度显著降低，从而诱发浅层土体的顺层失稳现象。

论文采用现场调研、现场试验、室内试验和理论分析相结合的研究方法对陕北不同地区的重塑黄土在冻融循环作用下的物理力学特性以及冻融病害发生机理进行了深入分析，所获得的研究成果不仅为后续探究陕北黄土路堑边坡的冻融致灾机制提供了理论参考，还会对冻融病害的防治工作具有一定的指导意义。

The loess region of Northern Shaanxi is located in the seasonally frozen soil area. The physical and mechanical properties of soil will deteriorate under the action of freeze-thaw cycle, which is one of the important reasons for the freeze-thaw disease of loess cutting slope. Therefore, this paper takes the problem of freeze-thaw disease of loess cutting slope in Northern Shaanxi as the starting point, through the physical and mechanical property test of remolded loess in Northern Shaanxi under different freeze-thaw cycles, obtains the variation law of basic physical parameters, mesoscopic pore structure and shear strength index of soil, so as to explore the influencing factors and disaster mechanism of freeze-thaw disease of loess cutting slope in Northern Shaanxi.

Through field investigation and field test, the occurrence environment characteristics and particle size distribution characteristics of loess in the study area are preliminarily mastered. At the same time, the phenomenon of freeze-thaw disease of loess cutting slope is summarized into two types: freeze-thaw spalling failure of Manually Excavated Slope and shallow freeze-thaw instability of natural slope. Among them, freeze-thaw spalling failure can be divided into four forms: skin, layer, fragment and mixed. Taking the remolded loess in different areas of Northern Shaanxi as the research object, the physical and mechanical properties tests under different freeze-thaw cycles are carried out. It is found that the increase of sample pore ratio gradually decreases after a sharp increase, and the initial pore structure is mainly micro and small pores, which is in a dynamic change process in the process of freezing and thawing. The cohesion and internal friction angle first decrease significantly and then tend to be stable in the process of freezing and thawing. The stress-strain curve will transition from weak softening type to weak hardening type with the increase of confining pressure. At the same time, the freezing and thawing damage model of loess in Northern Shaanxi under the triaxial stress state of equal confining pressure is also constructed. It is found that when the soil reaches the same damage degree, the strain of soil will increase with the increase of confining pressure, and the freeze-thaw damage rate decreases with the increase of freeze-thaw cycle times. After discussing the occurrence mechanism of freeze-thaw disease of loess cutting slope in Northern Shaanxi, it is finally considered that the main causes of freeze-thaw spalling failure of manually excavated slope are the mutual connection of macro cracks generated in the process of freeze-thaw and the separation of soil particles from the slope after freeze-thaw disintegration. The reason for the shallow freeze-thaw instability of natural slope is that the water will change the migration direction along the freeze-thaw interface during the infiltration process, and the interlayer cement will hydrolyze, resulting in the significant reduction of the shear strength of the soil at the interface, thus inducing the bedding instability of shallow soil.

This paper uses the research methods of field investigation, field test, laboratory test and theoretical analysis to deeply analyze the physical and mechanical properties and the occurrence mechanism of freeze-thaw diseases of remolded loess in different areas of Northern Shaanxi under the action of freeze-thaw cycle. The research results obtained not only provide a theoretical reference for the follow-up exploration of the freeze-thaw disaster mechanism of loess cutting slope in Northern Shaanxi, but also have a certain guiding significance for the prevention and control of freeze-thaw diseases.

[1] 周幼吾, 郭东信, 邱国庆, 等. 中国冻土[M]. 北京: 科学出版社, 2000.

[2] 徐学祖, 王家澄, 张立新. 冻土物理学[M]. 北京: 科学出版社, 2001.

[3] 陈仁升, 康尔泗, 吴立宗, 等. 中国寒区分布探讨[J]. 冰川冻土, 2005(04): 469-475.

[4] 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(04): 625-640.

[5] 张宗沽. 中国黄土[M]. 北京: 地质出版社, 1989.

[6] 李徐生, 韩志勇, 鹿化煜, 等. 下蜀黄土底界的年代及其对区域气候变干的指示[J]. 中国科学:地球科学, 2018, 48(02): 210-223.

[7] 王晓春, 张倬元. 寒区工程与冻融力学[J]. 地学前缘, 2000(S2): 99-104.

[8] 刘小军, 王铁行, 韩永强. 黄土窑洞病害调查及分析[J]. 地下空间与工程学报, 2007(06): 996-999.

[9] 方鹏. 黄土边坡剥落病害处治技术研究[D].长安大学, 2007.

[10] 段钊, 赵法锁, 陈新建. 陕北黄土高原区崩塌发育类型及影响因素分析——以吴起县为例[J]. 自然灾害学报, 2012, 21(06): 142-149.

[11] 叶万军, 陈义乾, 张登峰. 冻融作用下水分迁移对压实黄土强度影响的宏微观试验研究[J]. 中国公路学报, 2021, 34(06): 27-37.

[12] 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(S2): 2690-2694.

[13] 李宁, 程国栋, 谢定义. 西部大开发中的岩土力学问题[J]. 岩土工程学报, 2001(03): 268-272.

[14] 金会军, 李述训, 王绍令, 等. 气候变化对中国多年冻土和寒区环境的影响[J]. 地理学报, 2000(02): 161-173.

[15] 黄小铭. 我国寒区道路工程中冻土问题研究的回顾[J]. 冰川冻土, 1988(03): 344-351.

[16] 余以强. 短时冻土冻融损伤及边坡浅层稳定性研究[D]. 福州大学, 2015.

[17] 齐吉琳, 程国栋, P.A.Vermeer. 冻融作用对土工程性质影响的研究现状[J]. 地球科学进展, 2005(08): 887-894.

[18] 罗小刚, 陈湘生, 吴成义. 冻融对土工参数影响的试验研究[J]. 建井技术, 2000(02): 24-26+14.

[19] 肖东辉, 冯文杰, 张泽. 冻融循环作用下黄土孔隙率变化规律[J]. 冰川冻土, 2014, 36(04): 907-912.

[20] 肖东辉, 冯文杰, 张泽, 等. 冻融循环对兰州黄土渗透性变化的影响[J]. 冰川冻土, 2014, 36(05): 1192-1198.

[21] 周泓, 张泽, 秦琦, 等. 冻融循环作用下黄土基本物理性质变异性研究[J]. 冰川冻土, 2015, 37(01): 162-168.

[22] Wang S L, Lv Q F, Baaj H, et al. Volume change behaviour and microstructure of stabilized loess under cyclic freeze–thaw conditions[J]. Canadian Journal of Civil Engineering, 2016, 43(10): 865-874.

[23] 许健, 王掌权, 任建威, 等. 原状黄土冻融过程渗透特性试验研究[J]. 水利学报, 2016, 47(09): 1208-1217.

[24] Li G Y, Ma W, Mu Y H, et al. Effects of freeze-thaw cycle on engineering properties of loess used as road fills in seasonally frozen ground regions, North China[J]. Journal of Mountain Science, 2017, 14(2): 356-368.

[25] 董西好, 叶万军, 杨更社, 等. 温度对黄土热参数影响的试验研究[J]. 岩土力学, 2017, 38(10): 2888-2894+2900.

[26] Xu J, Wang S H, Wang Z Q, et al. Heat transfer and water migration in loess slopes during freeze–thaw cycling in Northern Shaanxi, China[J]. International Journal of Civil Engineering, 2018, 16(11): 1591-1605.

[27] Lu J, Wang T H, Cheng W C, et al. Permeability anisotropy of loess under influence of dry density and freeze–thaw cycles[J]. International Journal of Geomechanics, 2019, 19(9): 04019103.

[28] Liu X, Qin H, Lan H X. On the relationship between soil strength and wave velocities of sandy loess subjected to freeze-thaw cycling[J]. Soil Dynamics and Earthquake Engineering, 2020, 136: 106216.

[29] 張宗祜. 我国黄土类土显微結构的研究[J]. 地质学报, 1964(03): 357-369+375.

[30] 高国瑞. 黄土显微结构分类与湿陷性[J]. 中国科学, 1980(12): 1203-1208+1237-1240.

[31] 穆彦虎, 马巍, 李国玉, 等. 冻融作用对压实黄土结构影响的微观定量研究[J]. 岩土工程学报, 2011, 33(12): 1919-1925.

[32] 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(S2): 2690-2694.

[33] 杨更社, 田俊峰, 叶万军. 冻融循环对阳曲隧道黄土细观损伤演化规律影响研究[J]. 西安科技大学学报, 2014, 34(06): 635-640.

[34] 杨更社, 魏尧, 田俊峰, 等. 冻融循环对结构性黄土构度指标影响研究[J]. 西安科技大学学报, 2015, 35(06): 675-681.

[35] 倪万魁, 师华强. 冻融循环作用对黄土微结构和强度的影响[J]. 冰川冻土, 2014, 36(04): 922-927.

[36] 张泽, 马巍, 齐吉琳. 冻融循环作用下土体结构演化规律及其工程性质改变机理[J]. 吉林大学学报(地球科学版), 2013, 43(06): 1904-1914.

[37] 张泽, 周泓, 秦琦, 等. 冻融循环作用下黄土的孔隙特征试验[J]. 吉林大学学报(地球科学版), 2017, 47(03): 839-847.

[38] Yan C G, Zhang Z Q, Jing Y L. Characteristics of strength and pore distribution of lime-flyash loess under freeze-thaw cycles and dry-wet cycles[J]. Arabian Journal of Geosciences, 2017, 10(24): 1-10.

[39] 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(07): 2336-2343+2360.

[40] 叶万军, 李长清, 董西好, 等. 冻融环境下黄土微结构损伤识别与宏观力学响应规律研究[J]. 冰川冻土, 2018, 40(03): 546-555.

[41] Xu J, Wang Z Q, Ren J W, et al. Mechanism of shear strength deterioration of loess during freeze-thaw cycling[J]. Geomechanics and Engineering, 2018, 14(4): 307-314.

[42] Xu J, Li Y F, Ren C, et al. Influence of freeze-thaw cycles on microstructure and hydraulic conductivity of saline intact loess[J]. Cold Regions Science and Technology, 2021, 181: 103183.

[43] Li Z Y, Yang G S, Liu H. The Influence of Regional Freeze–Thaw Cycles on Loess Landslides: Analysis of Strength Deterioration of Loess with Changes in Pore Structure[J]. Water, 2020, 12(11): 3047.

[44] Wang S H, Wang Q Z, Xu J, et al. Effect of freeze-thaw on freezing point and thermal conductivity of loess[J]. Arabian Journal of Geosciences, 2020, 13(5): 1-15.

[45] 叶万军, 杨更社, 李喜安, 等. 冻结速率对Q2黄土性状影响的试验研究[J]. 岩石力学与工程学报, 2011, 30(09): 1912-1917.

[46] 周志军, 杨海峰, 耿楠, 等. 冻结速度对冻融黄土物理力学性质的影响[J]. 交通运输工程学报, 2013, 13(04): 16-21.

[47] 宋春霞, 齐吉琳, 刘奉银. 冻融作用对兰州黄土力学性质的影响[J]. 岩土力学, 2008(04): 1077-1080+1086.

[48] 魏尧, 杨更社, 叶万军. 冻结温度对冻融黄土力学特性的影响规律研究[J]. 长江科学院院报, 2018, 35(08): 61-66.

[49] 魏尧, 杨更社, 叶万军, 等. 冻融黄土无侧限抗压强度的析因实验[J]. 西安科技大学学报, 2019, 39(01): 103-111.

[50] Zhou Z W, Ma W, Zhang S J, et al. Effect of freeze-thaw cycles in mechanical behaviors of frozen loess[J]. Cold Regions Science and Technology, 2018, 146: 9-18.

[51] Xu J, Ren J W, Wang Z Q, et al. Strength behaviors and meso-structural characters of loess after freeze-thaw[J]. Cold Regions Science and Technology, 2018, 148: 104-120.

[52] Xu J, Li Y F, Lan W, et al. Shear strength and damage mechanism of saline intact loess after freeze-thaw cycling[J]. Cold Regions Science and Technology, 2019, 164: 102779.

[53] Li G Y, Wang F, Ma W, et al. Variations in strength and deformation of compacted loess exposed to wetting-drying and freeze-thaw cycles[J]. Cold Regions Science and Technology, 2018, 151: 159-167.

[54] 靳德武. 青藏高原多年冻土区斜坡稳定性研究[D]. 长安大学, 2004.

[55] 陈玉超. 冻融环境下岩土边坡稳定性研究初探[D]. 西安科技大学, 2006.

[56] 吴紫旺, 马巍. 冻土蠕变与强度[M]. 兰州: 兰州大学出版社, 1994．

[57] Wang B, French H M. In situ creep of frozen soil, Fenghuo Shan, Tibet Plateau, China[J]. Canadian Geotechnical Journal, 1995, 32(3): 545-552.

[58] Thompson E G, Sales F H. In situ creep analysis of room in frozen soil[J]. Journal of the Soil Mechanics and Foundations Division, 1972, 98(9): 899-915.

[59] Wang S H, Qi J L, Yin Z Y, et al. A simple rheological element based creep model for frozen soils[J]. Cold Regions Science and Technology, 2014, 106: 47-54.

[60] Ladanyi B, Johnston G H. Evaluation of in situ creep properties of frozen soils with the pressuremeter[C]// Proceedings of the 2nd International Permafrost Conference. 1973: 310-317.

[61] 牛富俊, 马立峰, 靳德武. 多年冻土地区斜坡稳定性评价问题[J]. 工程勘察, 2006(06): 1-3+17.

[62] 吴玮江. 季节性冻结滞水促滑效应——滑坡发育的一种新因素[J]. 冰川冻土, 1997(04): 71-77.

[63] 吴玮江. 季节性冻融作用与斜坡整体变形破坏[J]. 中国地质灾害与防治学报, 1996(04): 59-64+93.

[64] 那平山, 徐树林. 冻结滞水形成机制的探讨[J]. 冰川冻土, 1996(03): 83-88.

[65] 包斯琴, 丁延龙, 高永, 等. 地面裂缝对季节冻土中冻结滞水的影响[J]. 干旱区资源与环境, 2017, 31(05): 136-140.

[66] 李广, 张明礼, 叶伟林, 等. 甘肃黑方台坡面冻融特征及冻结滞水效应分析[J]. 干旱区资源与环境, 2021, 35(06): 117-122.

[67] 张茂省, 程秀娟, 董英, 等. 冻结滞水效应及其促滑机理——以甘肃黑方台地区为例[J]. 地质通报, 2013, 32(06): 852-860.

[68] 郑启浦. 东北多年冻土地区不良地质现象对铁路工程的危害及其防治[J]. 中国地质灾害与防治学报, 1993(01): 58-64.

[69] McRoberts E C, Morgenstern N R. The stability of thawing slopes[J]. Canadian Geotechnical Journal, 1974, 11(4): 447-469.

[70] 刘耕年, 熊黑钢. 天山高山冰缘环境的融冻泥流作用[J]. 地理学报, 1994(04): 363-370.

[71] 靳德武, 牛富俊, 陈志新, 等. 青藏高原融冻泥流型滑坡灾害及其稳定性评价方法[J]. 煤田地质与勘探, 2004(03): 49-52.

[72] 靳德武, 孙剑锋, 付少兰. 青藏高原多年冻土区两类低角度滑坡灾害形成机理探讨[J]. 岩土力学, 2005(05): 774-778.

[73] 郝君明, 吴通华, 李韧, 等. 青藏高原东北部青海玉树泥流滑坡特征和成因分析[J]. 冰川冻土, 2020, 42(02): 447-456.

[74] 周幼吾, 郭东信. 我国多年冻土的主要特征[J]. 冰川冻土, 1982(01): 1-19+95-96.

[75] 王绍令. 青藏公路风火山地区的热融滑塌[J]. 冰川冻土, 1990(01): 63-70.

[76] 牛富俊, 程国栋, 赖远明, 等. 青藏高原多年冻土区热融滑塌型斜坡失稳研究[J]. 岩土工程学报, 2004(03): 402-406.

[77] 靳德武, 牛富俊, 李宁. 青藏高原多年冻土区热融滑塌变形现场监测分析[J]. 工程地质学报, 2006(05): 677-682.

[78] 付小兵, 傅荣华, 夏克勤. 冻土斜坡的热融滑塌变形破坏机制分析与评估[J]. 水土保持研究, 2006(01): 243-244+268.

[79] 梁林林, 江利明, 周志伟, 等. 无人机遥感影像面向对象分类的冻土热融滑塌边界提取[J]. 国土资源遥感, 2019, 31(02): 180-186.

[80] 彭惠, 董元宏, 邵广军, 等. 青藏工程走廊热融滑塌灾害勘设要点与工程处治措施研究[J]. 灾害学, 2019, 34(S1): 72-76.

[81] 叶万军, 杨更社, 郭西山. 黄土边坡剥落病害的类型及其发育特征[J]. 西安科技大学学报, 2010, 30(01): 52-57.

[82] 叶万军, 杨更社, 彭建兵. 冻融循环导致洛川黄土边坡剥落病害产生机制的试验研究[J]. 岩石力学与工程学报, 2012, 31(01): 199-205.

[83] 马世雄. 冻融作用对黄土边坡剥落影响的试验研究[D]. 西安科技大学, 2012.

[84] 张辉, 王铁行, 许健. 黄土高原边坡冻融病害调查及现场测试研究[J]. 地下空间与工程学报, 2015, 11(05): 1339-1343.

[85] 许健, 郑翔, 张辉. 黄土地区边坡冻融剥落病害机理及稳定性分析[J]. 西安建筑科技大学学报(自然科学版), 2018, 50(04): 477-484.

[86] 符元帅. 短时冻区残积土边坡浅表层剥落机理研究[D]. 福州大学, 2017.

[87] 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(02): 163-166.

[88] 刘红军, 王丕祥. 公路土质边坡冻融失稳稳定性分析[J]. 哈尔滨工业大学学报, 2006(05): 764-766.

[89] 刘红军, 郭颖, 单炜, 等. 土质路堑边坡冻融失稳及植被护坡机理研究[J]. 岩土工程学报, 2011, 33(08): 1197-1203.

[90] 韩继国, 王选仓, 时成林, 等. 季节性冰冻地区公路边坡侵蚀破坏模式[J]. 长安大学学报(自然科学版), 2008(01): 41-45.

[91] 崔广芹, 尚志成, 秦迪. 基于冻融循环试验的季节性冻土区边坡稳定性分析[J]. 长江科学院院报, 2018, 35(08): 102-105+111.

[92] 蔡正银, 朱锐, 黄英豪, 等. 冻融过程对膨胀土渠道边坡劣化模式的影响[J]. 水利学报, 2020, 51(08): 915-923.

[93] 刘东生. 黄土与环境[M]. 北京: 科学出版社, 1985.

[94] 雷祥义, 魏青珂. 陕北伤亡性黄土崩塌成因与对策研究[J]. 岩土工程学报, 1998(01): 64-69.

[95] 曲永新, 张永双, 陈情来. 陕北晋西黄土滑塌灾害的初步研究——以西气东输工程为例[J]. 工程地质学报, 2001(03): 233-240.

[96] 魏青珂. 陕西崩塌灾害及其时空分布特征[J]. 灾害学, 1995(04): 55-59.

[97] 雷祥义. 中国黄土的孔隙类型与湿陷性[J]. 中国科学(B辑 化学 生物学 农学 医学 地学), 1987(12): 1309-1318.

[98] 余寿文, 冯西桥. 损伤力学[M]. 清华大学出版社, 1997.

[99] Kachanov L M . Time of the Rupture Process under Creep Conditions[J]. Izy. Akad. Nank. USSR. Otd. Teckhn. Nauk, 1958, 8: 26-31.

[100] Rabotnov Y N. On the equation of state of creep[J]. Proceedings of the Institution of Mechanical Engineers Conference Proceedings, 1963, 178(31): 117-122.

[101] Lemaitre J. Evalution of dissipation and damage in metals submitted to dynamic loading[C]// International Conference of Mechanical Behavior of Materials, 1971.

[102] Lemaitre J. How to use damage mechanics[J]. Nuclear Engineering and Design, 1984, 80(2): 233-245.

[103] 张全胜, 杨更社, 任建喜. 岩石损伤变量及本构方程的新探讨[J]. 岩石力学与工程学报, 2003(01): 30-34.

[104] 张升. 岩土材料本构模型的损伤统计理论研究[D]. 湖南大学, 2005.

[105] 刘松玉, 张继文. 土中孔隙分布的分形特征研究[J]. 东南大学学报, 1997(03): 129-132.

[106] Sasanian S, Newson T A. Use of mercury intrusion porosimetry for microstructural investigation of reconstituted clays at high water contents[J]. Engineering Geology, 2013, 158: 15-22.