| Lanslides are common nature disasters with the characters of widely distributed, frequencely occurrences,large damages.They will seriously threaten peoples' lives and properties,will cause serious loses once sliding.Landslide disasters happened in ShiXiakou southern mountain along the throat rout from Chengguan District of Lanzhou City to Jiuzhou's Development zone in September 17,2007,with a large number of loess and rock sliding and burying Jiuzhou Avenue.Jiuzhou Avenue is the only official channel zone in Jiuzhou,the landslide has seriously affected the road safty in Jiuzhou Development Zone, causing a great deal of inconvenience to the life and production of 50,000 residents and more than 100 units in the Development Zone;at the same time it has been a serious threat to Gansu People's Armed Police Corps depot opposite the landslide,causing a great concern from the government and the community.Although emergency measures has effectively control the disaster disk,temporarily stabilize the landslide,but the emergency works cannot eliminate the threat of landslides fundamentally.Therefore,it is necessary to develop comprehensive research on the landslide stability and management engineering design.Taking ShiXiakou landslides in Lanzhou as study object,the paper comprehensively the topography,lithology,geological structure,hydro-geological conditions and meteorological characteristics in this area based on the geological environment in the landslide area.Through on-site survey mapping,geophysical prospecting and indoor and outdoor experiments,the characteristics of the landslide have been studied systematically,pointing out the sliding characteristics of Multi-resolution and block and the deformation characteristics,analyzing the formation conditions and the influencing factors of the landslide,exploring the formation mechanism of the landslide.Engineering geology analysis and limit equilibrium method and numerical analysis are combined to evaluate the current steady-state of the landslide a qualitatively and quantitatively.Qualitative analysis showed that the overall sliding distance is only 5～7m and sliding potential is not fully released,the majority of slip body is not divorced from the slip bed,the overhead conditions in the front is favorable,based on which the stability of the slide is poor;The stability coefficient of the landslide under a natural state calculated by the limit equilibrium method is 1.051～1.074,but 0.956～1.042 in precipitation, and seismic conditions.The safety factors of landslide stability under a natural state calculated by Lagrangian Difference Method Based on Shear Strength Reduction in numerical analysis is 1.063.From the analysis of the shear strain maps and velocity vector maps,we can clearly see that the speed of the grid region in the plastic transfixion area and the lateral area of the sliding surface than that of other regions,showing the stability of the landslide is poorer.Three corresponding landslide control program have been brought forward by integrating the characteristics of the landslide,its formation mechanism and its evaluation findings of stability.After the election,it is recommended to use a comprehensive program,mainly concrete flame with prestressed anchor projects,supplemented by drainage works,partial side cut,slope protection works,concrete frame with anchor and landslide deformation monitoring. The focus is to make analysis and study on the design theories and its calculation method of concrete frame with prestressed anchor,the calculation method of internal force has been summed up,finally the attention proceeding in the construction management being put forward.Through the landslide stability analysis and control engineering research on ShiXiakou landslide,it is not only conductive to the improvement of the landslide,but also a reference for the stability analysis and control of the similar landslide.
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