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现代地质 ›› 2019, Vol. 33 ›› Issue (05): 1118-1127.DOI: 10.19657/j.geoscience.1000-8527.2019.003

• 环境地质学 • 上一篇    下一篇

藏东德弄弄巴古滑坡堆积体物理力学特征及稳定性分析

詹美强1,2,3(), 葛永刚1,2(), 贾利蓉4, 严华1,2,3   

  1. 1.中国科学院 水利部成都山地灾害与环境研究所,四川 成都 610041
    2.中国科学院 山地灾害与地表过程重点实验室,四川 成都 610041
    3.中国科学院大学,北京 100049
    4.四川省苍梧县交通运输局,四川 广元 628400
  • 收稿日期:2018-07-30 修回日期:2019-04-24 出版日期:2019-10-26 发布日期:2019-10-28
  • 通讯作者: 葛永刚
  • 作者简介:葛永刚,男,研究员, 1974年出生,自然地理学专业,主要从事山地灾害及预警技术研究工作。Email: gyg@imde.ac.cn
    詹美强,男,硕士研究生,1994年出生,岩土工程专业,主要从事山地灾害防灾减灾技术研究。Email: geoloist_zhan@126.com
  • 基金资助:
    国家自然科学基金项目(41471010);国家自然科学基金项目(41790432)

Study on Physical and Mechanical Characteristics and Stability Analysis of Ancient Landslide Deposit in East Tibet

ZHAN Meiqiang1,2,3(), GE Yonggang1,2(), JIA Lirong4, YAN Hua1,2,3   

  1. 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu,Sichuan 610041,China
    2. Key Laboratory of Mountain Surface Process and Hazard, Chinese Academy of Sciences, Chengdu,Sichuan 610041,China
    3. University of Chinese Academy of Sciences,Beijing 100049,China
    4. Cangwu Road Transport Bureau,Guangyuan,Sichuan 628400,China
  • Received:2018-07-30 Revised:2019-04-24 Online:2019-10-26 Published:2019-10-28
  • Contact: GE Yonggang

摘要:

拟建川藏铁路是自然、地质环境最为复杂的铁路工程,地质灾害作为局部乃至全线的关键控制节点,关乎川藏铁路建设的成败。野外调查表明,德弄弄巴古滑坡位于藏东地区藏曲河右岸一级阶地上,在川藏铁路选线或建设过程中备受关注,其稳定性是直接影响着铁路选线的必要条件。本文在野外调查的基础上, 对德弄弄巴古滑坡堆积体的物理力学特征和稳定性进行系统分析和计算。结果表明:天然工况下,组成德弄弄巴古滑坡的碎石土干密度达1.75 g/cm3以上,含水率低于4%,并且堆积体的黏聚力和内摩擦角与含水率呈显著相关性,随含水率增加而减小;基于FLAC3D数值模拟和GEO-SLOPE稳定性分析表明,堆积体在天然和暴雨工况下整体稳定,但在强降雨条件下,坡脚和坡体后缘地形转折处稳定性较差,坡脚稳定性系数仅0.761。该滑坡在暴雨、地震和人类活动等作用下,极有可能发生局部失稳,影响铁路建设和坡体上居民安全,应进行必要的综合治理和稳定性监测。

关键词: 川藏铁路, 古滑坡, 物理力学特征, 数值模拟

Abstract:

The proposed Sichuan-Tibet Railway is the most complicated railway in nature and geological environment. The geological disaster, as a key control node of local and even the whole line, is related to the success or failure of Sichuan-Tibet Railway construction. Field investigation shows that the Denongnongba ancient landslide is located on the first order land of the right bank in Zangqu River, and has attracted much attention in the process of railway line selection or construction in Sichuan and Tibet, and its stability is a necessary condition for railway selection line. Based on field investigation, this paper systematically calculated and analyzed the physical and mechanical parameters and stability of the ancient landslide deposit. The results show that under natural conditions, the dry density of gravel is above 1.75 g/cm3, and the water content is less than 4%, and the cohesion and internal friction angle of the deposit are significantly correlated with water content, which decreases with the increase of water content. Based on FLAC3D numerical simulation and GEO-SLOPE stability result, it is shown that the landslide deposit is stable under natural and rainstorm conditions, but the stability of toe and the posterior edge of slope is poor under heavy rainfall condition, and the stability coefficient of toe is only 0.761. Under the action of rainstorm, earthquake and human activity, the deposit is likely to be local instability, which affects the safety of railway construction and the residents on the slope, and it is necessary to take comprehensive management and stability monitoring to the landslide.

Key words: Sichuan-Tibet Railway, ancient landslide, physical and mechanical parameter, numerical simulation

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