降雨作用下露天矿山边坡失稳机理研究

Study on the mechanism of slope instability in open pit mines under the effect of rainfall

中文关键词: 现场监测  干湿循环  降雨作用  Geo-studio  边坡稳定性中图分类号:TD216文献标志码:A文章编号:1674-7801(2025)02-0412-10

英文关键词: field monitoring  wet and dry cycle  rainfall action  Geo-studio  slope stability

中文摘要:

      为分析露天矿山边坡的稳定性，通过资料调研与现场监测等手段分析认为降雨是导致依托工程露天矿山边坡失稳的主要原因。通过试验确定其表层土石混合体的饱和渗透系数及力学性质，选用 Geo-studio有限元软件进行不同降雨工况的数值模拟，得到如下结论:(1)边坡表层土体受到干湿循环作用后，抗剪强度会出现明显劣化；前三次干湿循环作用时，土体抗剪强度劣化速率较高；(2)降雨使得坡表土体水平位移显著增加，而降雨结束后，雨水仍然在坡内迁移，导致坡内孔隙水压力不断上升；(3)降雨时间、降雨量和干湿循环次数的增加都会使得边坡稳定性降低；短期强降雨更易造成边坡失稳破坏。本研究可为类似露天矿山边坡失稳机理研究及防治提供相应技术支撑。

英文摘要:

      To comprehensively investigate the stability of open-pit mine slopes, this study identifies rainfall asthe primary trigger for slope instability in the analyzed project through integrated data analysis and field monitoring.Laboratory tests were conducted to determine the saturated permeability coefficient and mechanical properties ofthe surface soil-rock mixture in the basal soil layer. GeoStudio finite element software was employed to simulateslope behavior under diverse rainfall scenarios, enabling an analysis of stability evolution patterns. Key findings in-clude: (1)Repeated wet-dry cycles significantly degrade the shear strength of the slope's surface soil, with cohesion exhibiting the most pronounced deterioration. Notably, the rate of shear strength reduction is highest during the ini-tial three cycles. (2)Rainfall induces a marked increase in horizontal displacement of the slope's surface soil. Post-rainfall, residual water migration within the slope leads to a sustained rise in internal pore water pressure. (3)Ex-tended rainfall duration, higher rainfall intensity, and increased wet-dry cycles collectively reduce slope stability.Under equivalent conditions, short-duration heavy rainfall poses a greater risk of slope failure.This research pro-vides critical insights into slope instability mechanisms and offers technical guidance for hazard prevention in analo-gous open-pit mining environments.