Influence of air temperature change on stability of permafrost slope: A case study of shallow permafrost landslide in Qinghai Province
-
摘要:
受气温变化影响，浅层冻土滑坡失稳涉及水分的固液相态转换，是一个复杂的水热力耦合过程。为揭示气温变化对多年冻土斜坡稳定性的影响，基于冻土水热力耦合数值模型，模拟了2020—2024年青海省多年冻土区斜坡水热力演化过程。研究结果表明：水分迁移速率呈周期性变化，每年5—10月活动层融化程度高，总体积含水率变化趋势显著；夏季多年冻土上限以下的高含冰量土层融化产生厚度约15 cm的富水层，孔隙水压难以消散；4年间多年冻土上限下移10.4 cm，导致活动层和富水层的厚度增大，上覆融土下滑力增大、抗滑力减小，土体抗剪强度进一步下降；活动层土体每年产生数厘米冻胀融沉变形，抗剪强度不断劣化，坡脚处最容易形成薄弱带。
Abstract:Under the influence of air temperature change, shallow permafrost landslide is a complex thermal-hydro-mechanical coupling process, which involves the transformation of water between solid state and liquid state. To reveal the influence of air temperature change on the shallow permafrost landslide, based on the coupled thermal-hydro-mechanical model for frozen soil, the thermal-hydro-mechanical evolution process of slope in permafrost region from 2020 to 2024 is simulated. The results are as follows: the rate of water migration presents periodic variation. The thawing degree of the active layer from May to October is high, causing the variation trend of total water content significantly. In summer, the thawing of the high ice content layer below the permafrost table forms a water-rich layer of 15 cm thickness approximately, causing excess pore water pressure difficult to dissipate. The permafrost table will decline by 10.4 cm in 4 years, and the thickness of the active layer and water-rich layer increased. As a result, the sliding force of the overlying thawed soil increases, the sliding resistance decreases, and the shear strength of the soil further decreases. Several centimeters displacement of frost heave and thaw settlement occurs in the active layer per year, shear strength deteriorates continuously, and the weak zone is easiest formed at slope toe.
-
-
表 1 地层物理力学参数
Table 1. Physical and mechanical parameters of formation
参数 活动层 多年冻土层 基岩层 密度/（kg·m−3） 1800 2000 2500 弹性模量/MPa 40 30 5000 泊松比 0.25 0.3 0.15 渗透系数/（m·s−1） 1.2×10−6 8×10−10 0 黏聚力/kPa 12 35 — 内摩擦角/（°） 22 20 — 
下载: 导出CSV
-
[1] LEWKOWICZ A G. Dynamics of active-layer detachment failures,Fosheim Peninsula,Ellesmere Island,Nunavut,Canada[J]. Permafrost and Periglacial Processes,2007,18(1):89 − 103. doi: 10.1002/ppp.578
[2] HUSCROFT C A,LIPOVSKY P,BOND J D,et al. Permafrost and landslide activity:Case studies from southwestern Yukon Territory[J]. Yukon exploration and geology,2003:107 − 119.
[3] LEWKOWICZ A G,HARRIS C. Frequency and magnitude of active-layer detachment failures in discontinuous and continuous permafrost,northern Canada[J]. Permafrost and Periglacial Processes,2005,16(1):115 − 130. doi: 10.1002/ppp.522
[4] LAMOUREUX S F,LAFRENIÈRE M J. Fluvial impact of extensive active layer detachments,cape bounty,Melville Island,Canada[J]. Arctic,Antarctic,and Alpine Research,2009,41(1):59 − 68. doi: 10.1657/1523-0430-41.1.59
[5] PATTON A I,RATHBURN S L,CAPPS D M,et al. Ongoing landslide deformation in thawing permafrost[J]. Geophysical Research Letters,2021,48(16):1 − 2.
[6] 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(5):774 − 778. [JIN Dewu,SUN Jianfeng,FU Shaolan. Discussion on landslides hazard mechanism of two kinds of low angle slope in permafrost region of Qinghai-Tibet plateau[J]. Rock and Soil Mechanics,2005(5):774 − 778. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2005.05.019
[7] RAN Youhua,LI Xin,CHENG Guodong,et al. Mapping the permafrost stability on the Tibetan Plateau for 2005−2015[J]. Science China Earth Sciences,2021,64(1):62 − 79.
[8] 梁虹,张为为,农华. 青海省气温空间变化特征分析[J]. 气象研究与应用,2017(增刊 1):52 − 53. [LIANG Hong,ZHANG Weiwei,NONG Hua. Analysis of spatial variation characteristics of air temperature in Qinghai Province[J]. Journal of Guangxi Meteorology,2017(Sup 1):52 − 53. (in Chinese with English abstract)
[9] 刘广岳,谢昌卫,杨淑华. 青藏公路沿线多年冻土区活动层起始冻融时间的时空变化特征和影响因素[J]. 冰川冻土,2018,40(6):1067 − 1078. [LIU Guangyue,XIE Changwei,YANG Shuhua. Spatial and temporal variation characteristics on the onset dates of freezing and thawing of active layer and its influence factors in permafrost regions along the Qinghai-Tibet highway[J]. Journal of Glaciology and Geocryology,2018,40(6):1067 − 1078. (in Chinese with English abstract) doi: 10.7522/j.issn.1000-0240.2018.0413
[10] 魏赛拉加,严慧珺,张俊才,等. 青海省地质灾害防治资金投入与成效分析[J]. 中国地质灾害与防治学报,2020,31(5):112 − 116. [WEI Sailajia,YAN Huijun,ZHANG Juncai,et al. Analysis of funding used for geological disaster prevention in Qinghai Province and its effects[J]. The Chinese Journal of Geological Hazard and Control,2020,31(5):112 − 116. (in Chinese with English abstract)
[11] MCKENZIE J M,VOSS C I. Permafrost thaw in a nested groundwater-flow system[J]. Hydrogeology Journal,2013,21(1):299 − 316. doi: 10.1007/s10040-012-0942-3
[12] 庞伟军,常刚,苟海瑞,等. 青海204省道祁默段沿线多年冻土发育特征[J]. 冰川冻土,2019,41(1):93 − 99. [PANG Weijun,CHANG Gang,GOU Hairui,et al. Characteristics of the permafrost from Qilian to mole of the highway 204 in Qinghai Province[J]. Journal of Glaciology and Geocryology,2019,41(1):93 − 99. (in Chinese with English abstract) doi: 10.7522/j.issn.1000-0240.2019.0102
[13] 庞强强,赵林,李述训. 局地因素对青藏公路沿线多年冻土区地温影响分析[J]. 冰川冻土,2011,33(2):349 − 356. [PANG Qiangqiang,ZHAO Lin,LI Shuxun. Influences of local factors on ground temperatures in permafrost regions along the Qinghai-Tibet highway[J]. Journal of Glaciology and Geocryology,2011,33(2):349 − 356. (in Chinese with English abstract)
[14] WANG Baolin, NICHOL S, SU Xueqing. Geotechnical field observations of landslides in fine-grained permafrost soils in the Mackenzie valley, CanadaLandslides, 2005: 203 − 212.
[15] 樊圆圆,宋玲,魏学利. 基于水槽试验的冰碛土泥石流启动机理分析:以中巴公路艾尔库然沟为例[J]. 中国地质灾害与防治学报,2021,32(1):1 − 9. [FAN Yuanyuan,SONG Ling,WEI Xueli. Analysis of the start-up mechanism of moraine debris flow based on flume test:A case study of the Aierkuran Gully along the Sino-Pakistan highway[J]. The Chinese Journal of Geological Hazard and Control,2021,32(1):1 − 9. (in Chinese with English abstract)
[16] HARLAN R L. Analysis of coupled heat-fluid transport in partially frozen soil[J]. Water Resources Research,1973,9(5):1314 − 1323. doi: 10.1029/WR009i005p01314
[17] 白青波. 附面层参数标定及冻土路基水热稳定数值模拟方法初探[D]. 北京: 北京交通大学, 2016
BAI Qingbo. Determination of boundary layer parameters and a preliminary research on hydrothermal stability of subgrade in cold region[D]. Beijing: Beijing Jiaotong University, 2016. （in Chinese with English abstract）
[18] 邓友生,何平,周成林,等. 含盐土渗透系数变化特征的试验研究[J]. 冰川冻土,2006,28(5):772 − 775. [DENG Yousheng,HE Ping,ZHOU Chenglin,et al. Experimental study of permeability coefficient of saline soils[J]. Journal of Glaciology and Geocryology,2006,28(5):772 − 775. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-0240.2006.05.022
[19] 张虎,张建明,张致龙,等. 冻结状态青藏粉质黏土的渗透系数测量研究[J]. 岩土工程学报,2016,38(6):1030 − 1035. [ZHANG Hu,ZHANG Jianming,ZHANG Zhilong,et al. Measurement of hydraulic conductivity of Qinghai-Tibet Plateau silty clay under subfreezing temperatures[J]. Chinese Journal of Geotechnical Engineering,2016,38(6):1030 − 1035. (in Chinese with English abstract) doi: 10.11779/CJGE201606008
[20] 刘为民,何平,张钊. 土体导热系数的评价与计算[J]. 冰川冻土,2002,24(6):770 − 773. [LIU Weimin,HE Ping,ZHANG Zhao. A calculation method of thermal conductivity of soils[J]. Journal of Glaciolgy and Geocryology,2002,24(6):770 − 773. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-0240.2002.06.013
[21] 张玉芝,杜彦良,孙宝臣. 季节性冻土地区高速铁路路基地温分布规律研究[J]. 岩石力学与工程学报,2014,33(6):1286 − 1296. [ZHANG Yuzhi,DU Yanliang,SUN Baochen. Temperature distribution in roadbed of high-speed railway in seasonally frozen regions[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(6):1286 − 1296. (in Chinese with English abstract)
[22] 白明,牛丽娟,魏荣妮. 近58年来祁连山中段气温时空变化[J]. 青海气象,2019(2):12 − 14. [BAI Ming,NIU Lijuan,WEI Rongni. Temporal and spatial variation of air temperature in the middle Qilian Mountains in recent 58 years[J]. Journal of Qinghai Meteorology,2019(2):12 − 14. (in Chinese with English abstract)
[23] 李同录,李颖喆,赵丹旗,等. 对水致黄土斜坡破坏模式及稳定性分析原则的思考[J]. 中国地质灾害与防治学报,2022,33(2):25 − 32. [LI Tonglu,LI Yingzhe,ZHAO Danqi,et al. Thoughts on modes of loess slope failure triggered by water infiltration and the principals for stability analysis[J]. The Chinese Journal of Geological Hazard and Control,2022,33(2):25 − 32. (in Chinese with English abstract)
[24] 晏长根,王婷,贾海梁,等. 冻融过程中未冻水含量对非饱和粉土抗剪强度的影响[J]. 岩石力学与工程学报,2019,38(6):1252 − 1260. [YAN Changgen,WANG Ting,JIA Hailiang,et al. Influence of the unfrozen water content on the shear strength of unsaturated silt during freezing and thawing[J]. Chinese Journal of Rock Mechanics and Engineering,2019,38(6):1252 − 1260. (in Chinese with English abstract)
[25] HARRIS C,LEWKOWICZ A G. An analysis of the stability of thawing slopes,Ellesmere Island,Nunavut,Canada[J]. Canadian Geotechnical Journal,2000,37(2):449 − 462. doi: 10.1139/t99-118
[26] HINKEL K M. Spatial and temporal patterns of active layer thickness at Circumpolar Active Layer Monitoring (CALM) sites in northern Alaska,1995–2000[J]. Journal of Geophysical Research Atmospheres,2003,108(D2):8168. doi: 10.1029/2001JD000927
-
图(12)
表(1)
计量
- 文章访问数: 1068
- PDF下载数: 24
- 施引文献: 0