The Stability Evaluation And Control Engineering Design Of The Unstable Slope In The Urban Area Of Gansu Diebu County

Diebu county which is located in the southeast of Gansu is one of the area with the most severe geological disaster in China,and also is an important natural protection area in China.Controlled by the bad geological environment conditions and influenced by extreme climate and aggravation of human engineering activity,geological disasters are frequent in Diebu county,which cause huge casualties and property losses every year and seriously affect economic and social development.There are still a lot of hidden dangers of geological disasters,especially the unstable loess slopes are the most prominent.Based on detailed geological survey and qualitative analysis,this paper takes 5 unstable slopes which have been deformed at different degrees in the urban area of Diebu county as the research object,evaluates the stability of slopes and puts forward corresponding slope control engineering measures.Using the rigid body limit equilibrium method,this paper does quantitative evaluation to the stability of slopes under different working conditions.The results show that: the 5 slopes are in basically-stable or less-stable status under current conditions;if under working condition with rainstorm,they will be in less-stable or unstable status;if under working condition with earthquake,they will be in unstable status.It is found by analysis that in addition to the rainstorm,the earthquake disturbance and human engineering activity are also the external factors that induces the slope to collapse.According to the current conditions of slope and engineering geological characteristics,this paper designs the unstable slope control engineering measures for the 5 slopes combining with smoothing slope,protecting slope with frame,anchor(anchor cable),retaining wall(plank)and drainage engineering.When the stability factor of reinforced slopes is greater than safety factor in any working conditions,it will achieve the purpose of prevention,which have great practical significance to protect the life and property safety and to guarantee the social stability and social economic development of Diebu County.