长期降雨作用下黄土边坡失稳模型试验

Model test study on instability of loess slopes under long-term rainfall

黄土滑坡具有危害大、分布广等特点,一直是工程地质研究热点。为研究长期降雨作用下黄土边坡的稳定性变化规律,以洛川林业局沟北边坡为原型,利用自主研发的降雨装置,开展了室内边坡人工降雨模型试验,通过对边坡5次循环降雨全过程监测,分析长期降雨对边坡稳定性的影响。结果表明,降雨过程中,湿润锋运移速度、孔隙水压力与土压力均随降雨时间的增加而呈现总体增长的趋势,而土压力则由于冲刷的原因持续减小。通过对降雨循环后边坡稳定性变化规律的分析及与数值模拟计算结果的比较发现,长期降雨作用会使边坡稳定性持续降低。研究结果可为进一步分析黄土滑坡破坏机理提供参考依据。

Loess landslides have always been a hotspot in engineering geology due to their large hazards and wide distribution.To study the stability of the loess slopes under long-term rainfall,the north slope of Luochuan Forestry Bureau was applied as a prototype and the self-developed rainfall device was used.An indoor slope artificial rainfall model test was carried out.Through monitoring the whole process of five cycles of rainfall,the impact of rainfall on the slope stability was analyzed.The results show that the humid front migration velocity,pore water pressure and earth pressure present an overall increasing trend with the increase of rainfall time during the rainfall process,while the earth pressure continues to decrease due to erosion.By the analysis of the slope stability change law and the numerical simulation calculation,it is found that the long-term rainfall effect will reduce the slope stability continuely.The research results are intended to provide a reference for further analysis of the failure mechanism of loess landslides.