灌溉及降雨诱发文冠谷北坡土质滑坡成因分析

Analysis of the Causes of Soil Landslides on the Northern Slope of Wenguan Valley Induced by Irrigation and Rainfall

通过现场调查、室内试验,分析头屯河区二号台地某土质滑坡形成原因、滑动机制。斜坡临空面坡脚前期受灌溉饱水、浸泡坡脚,坡体裂缝渗透增强,产生渗透压力。右岸人工弃碴堆积,原有沟谷中水被挤向左岸而浸泡坡脚,起到软化坡脚的作用,后期坡面泥流整体在沟谷中水上以“气垫船”的形式继续运移。当有弱透水层时,水长期浸泡斜坡土体,坡体中饱水区域由坡脚向上扩展,在灌溉+降雨诱发条件下坡体变形、失稳、突滑。建议尽快抽排滑坡上游坡脚积水,隔离栏杆下设过水涵管排水,停止右岸人工弃渣的堆积、并做支护,在下游沟谷开阔处可考虑修小型储水池,便于就地储备绿化用水。

The author analyzes the causes and sliding mechanism of a soil landslide on the No.2 platform of Toutun Rrver District through field investigation and laboratory experiment.The slope toe of the empty surface of the slope is saturated with water and soaked in the early stage of the slope,and the penetration of the cracks in the slope is enhanced,and seepage pressure is generated.The artificial dumping on the right bank accumulates,and the original valley water is squeezed to the left bank and soaks the toe of the slope to soften the toe of the slope.Later,the mud flow on the slope will continue to move on the middle water of the valley in the form of a"hovercraft";Water soaks the slope soil for a long time in the impermeable layer,and the saturated area in the slope extends upward from the slope toe.Under the conditions of irrigation+rainfall,the slope deforms,loses stability,and suddenly slips.It is recommended to drain the accumulated water at the foot of the landslide as soon as possible,set up a water culvert under the isolation railing,stop the accumulation of artificial slag on the right bank,and do support,and consider building a small storage tank in the open valley downstream to facilitate on-site storage of greening Use water.