长江科学院院报 ›› 2020, Vol. 37 ›› Issue (5): 74-78.DOI: 10.11988/ckyyb.20190173

• 工程安全与灾害防治 • 上一篇    下一篇

白格堰塞湖泄流对上游岸坡稳定性的影响

张磊, 由金玉   

  1. 四川水利职业技术学院,成都 611231
  • 收稿日期:2019-02-25 出版日期:2020-05-01 发布日期:2020-06-10
  • 作者简介:张 磊(1983-),男,山东齐河人,讲师,硕士,主要从事水利工程方面的教学与研究工作。E-mail: 68174476@qq.com

Stability of Upstream Bank Slope Affected by Discharge ofBaige Barrier Lake

ZHANG Lei, YOU Jin-yu   

  1. Sichuan Water Conservancy Vocational College, Chengdu 611231, China
  • Received:2019-02-25 Online:2020-05-01 Published:2020-06-10

摘要: 2018年10月11日,位于西藏江达县和四川白玉县交界处的金沙江沿岸发生了大型山体滑坡——白格滑坡,造成金沙江堵塞并形成堰塞湖;2018年11月3日该处发生二次滑坡,再次堵江并造成堰塞湖蓄水量增加。为了研究白格堰塞湖在人工挖槽泄流阶段对上游岸坡稳定性的影响,以堰塞体上游某天然岸坡为例,采用有限元软件PLAXIS研究了该边坡在水位下降过程中的变形特征及稳定性变化规律。结果表明:①随着堰塞湖水的逐渐泄流,坡体表面位移变形逐渐增大,坡体后缘部位最大位移达到8.5 cm,中部和前缘变形相对较小;②水位下降过程中,坡体后缘的塑性区向下扩展,但未形成贯通的塑性区,同时安全系数也逐渐减小,最终为1.16;③各降水阶段坡体的最不利滑裂面相同,滑弧剪出口位于滑坡体高程3 150 m处,距坡脚约250 m,确定了该岸坡潜在的滑坡形式为高位滑坡。研究成果对后期该区域滑坡灾害的预防和控制有一定参考价值。

关键词: 白格滑坡, 岸坡稳定, 堰塞湖, PLAXIS, 安全系数, 塑性区

Abstract: On October 11, 2018, a large-scale landslide (Baige landslide) took place along the Jinsha River at the junction of Jiangda County in Tibet and Baiyu County in Sichuan Province, which resulted in blockage of the Jinsha River and formed a barrier lake. On November 3, 2018, a second landslide occurred in this area, blocked the river again and raised the water storage capacity of the barrier lake. In order to study the influence of Baige barrier lake on the stability of upstream bank slope during the discharge of the barrier lake through artificial trench, we examined the deformation characteristics and stability variation law of a natural bank slope in the upstream of the barrier lake in the process of water level drawdown using finite element software PLAXIS. Results evinced that: (1) with the discharg of barrier lake, the deformation of slope surface gradually increased, and the maximum displacement at the back edge of the slope reached 8.5 cm, while the deformations in the middle and the front edge were relatively small; (2) in the process of water level descent, the plastic zone at the back edge of the slope expanded downward, yet with no plastic zone penetrated, and meanwhile the safety factor reduced gradually until reaching 1.16; (3) the most unfavorable slipping surface of slope at different stages of water level drawdown remained the same. The exit of the slipping arc located at elevation 3 150 m of the landslide body and about 250 m from the slope foot. Therefore, we conclude that the potential sliding form of the bank slope is a high-level landslide. The research results are of referential value for future prevention and control of landslide disasters in this region.

Key words: Baige landslide, slope stability, barrier lake, PLAXIS, safety factor, plastic zone

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