Stability Analysis And Control Measures Of Dongshan H3-1 Landslide In Xihe County

China is a country with frequent geological disasters,especially landslides.According to the types of geological disasters in China in 2016,landslides account for76.2% of the total disasters,which are very harmful geological disasters.Xihe County,Longnan City,Gansu Province,is located in the upper reaches of Yangshui River,a tributary of Hanshui River in Jialing Jiangxi Province,which is located in Xili Basin.In view of this,in order to grasp the characteristics of landslides in this area and control measures,relying on the Xihe County Dongshan H3-1 landslide control project,in combination with qualitative and quantitative means to evaluate the stability of the Xihe County Dongshan H3-1 landslide,the effectiveness and suitability of its control programs and measures to carry out a comprehensive study.The main research work is as follows:(1)The geological background of Dongshan H3-1 landslide is preliminarily understood by collecting the related meteorological and hydrological,topographic and geomorphological features,geological structure,rock and soil types,human engineering activities and other geological environment characteristics.This area has abundant precipitation and significant space-time difference,complex topography and geological structure,multiple stratigraphic and lithologic assemblages,strong neotectonic movement and moderate human engineering activity,which provides the premise and foundation for deformation and failure of Dongshan H3-1 landslide.(2)Understanding the characteristics of regional geological environment,using surveying and mapping as a means to grasp the morphological characteristics of the slope,combined with drilling and pit exploration and other means of comprehensive investigation of the material composition of the slope,and based on this to take the typical section of the original sample,to carry out physical and mechanical engineering characteristics of the relevant testing indicators.The results show that the sliding body soil is silty clay with loose structure,pore development and low water content,which is favorable for surface water infiltration;the sliding zone soil is semi-diagenetic mudstone debris with poor cementation,belonging to extremely soft rock,weak weathering resistance,low mechanical strength and muddy under saturated condition;the sliding bed is mudstone,and the upper part belongs to strong weathering mudstone and rock.The rock mass is fragmented,the mechanical strength is low,and it is easy to soften in water,which provides the material basis for the occurrence of landslide.(3)Combining with the geological environment characteristics and landslide development characteristics of Dongshan H3-1 landslide area,the influencing factors and development mechanism of landslide are preliminarily analyzed.On this basis,the stability of landslide is analyzed and evaluated by qualitative and quantitative analysis methods.The natural history analysis method is applied to qualitative analysis,and the limit equilibrium method and number are selected for quantitative analysis.Value simulation method,because the landslide is most likely to be affected by rainfall and earthquake disaster,so the natural conditions,rainfall conditions and seismic conditions of the landslide under the typical section of the calculation,and then comprehensive evaluation of stability.Through qualitative and quantitative analysis,it can be seen that H3-1 landslide is a push-type landslide,and it appears instability under rainfall and earthquake conditions,which is consistent with the actual investigation.(4)In view of the poor stability of H3-1 landslide,the necessity of its treatment is summarized,and the prevention and control principles and objectives are given.At the same time,the concrete treatment scheme is given,that is,anti-slide pile at the foot of slope,backpressure by tamping and comprehensive drainage,and combined with the use of soil nails and anchor cables for comprehensive treatment.Finally,the Midas GTS NX finite element software is used to check the numerical value of the reinforced landslide,verifying the rationality of the reinforcement scheme,which has important reference value and reference significance for similar projects.