植被覆盖对季节冻土区黄土斜坡水热变化及稳定性影响  

Influences of vegetation coverage on hydrothermal change and stability of loess slope in seasonal frozen soil area

作　　者：李广 汤明高[1] 张明礼[2] 左炙坪 帅奕垚 LI Guang;TANG Minggao;ZHANG Mingli;ZUO Zhiping;SHUAI Yiyao(State Key Laboratory of Geohazard Prevention and Geo-environment Protection,Chengdu University of Technology,Chengdu 610059;College of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059 [2]兰州理工大学土木工程学院,兰州730050

出　　处：《干旱区资源与环境》2024年第1期133-142,共10页Journal of Arid Land Resources and Environment

基　　金：国家自然科学基金重大专项(41941019);国家自然科学基金(42261028);中国科学院“西部青年学者”项目(张明礼,23JR6KA027);陇原青年创新创业人才(个人)项目(张明礼);地质灾害防治与地质环境保护国家重点实验室自主研究课题(SKLGP2021Z005)资助。

摘　　要：植被覆盖对斜坡土壤水热变化具有显著影响,而水热变化会导致斜坡地下水位、稳定性改变。以黑方台斜坡植被覆盖区域、无植被区域的土壤温度与含水量监测数据为基础,基于水热力耦合数值模型,研究植被覆盖对季节冻土区斜坡土壤水热与稳定性影响。结果表明:1)无植被区域土体冻结深度更厚,冻结持续时间更长,促进地下水往植被覆盖区域渗流,导致植被覆盖区域土壤含水量更高。2)在冻结期,无植被区域地下水位的上涨幅度高于植被覆盖区域,在相同灌溉条件下,植被覆盖区域更容易发生滑动,其滑移面也更陡。(3)黑方台植被覆盖区域滑坡具有渐进后退式演化特点,每次滑移面均会沿滑坡后壁凹槽底部发生,形成逐级后退的破坏模式。The vegetation coverage has a significant effect on the hydrothermal changes of slope soil,and the hydrothermal changes will lead to the change of groundwater level and slope stability.Based on the monitoring data of temperature and water content of soil in vegetation-covered and non-vegetation areas in the Heifangtai slope,the influences of vegetation cover on soil temperature,water content and slope stability were studied in seasonal frozen soil area by means of thermo-hydromechanical coupling numerical model.The results show that:1)The soil in the non-vegetation area has a thicker freezing depth and a longer freezing duration,which promotes the seepage of groundwater to the vegetation-covered area,resulting in higher soil moisture in the vegetation-covered area.2)In the freezing period,the increase of groundwater table in the non-vegetation area is higher than that in the vegetation-covered area.Under the same irrigation conditions,the vegetation-covered area is more prone to landslides,and it's slip surface is steeper.3)The landslides in the vegetation-covered area have the characteristics of gradual retrogressive evolution.The slip surface will occur along the bottom of the groove on the back wall of the landslides,forming a gradual failure mode.

关 键 词：植被覆盖 斜坡稳定性 数值模拟 水热变化 黑方台 

分 类 号：P642.22[天文地球—工程地质学]