Research On The Stability Of Slope Soft Soil Embankment And Foundation Treatment

With the rapid development of high-speed railway in China,the high-speed railway network is gradually covered by the east to the central and western regions.In the construction of high-speed railway in western China,slope soft soil foundation as a kind of common bad geological type has important influence on engineering construction.Building high speed rail on slope soft soil foundation,due to the dual action of slope and soft soil,the roadbed is prone to some engineering problems such as large differential settlement and lateral deformation,slope instability etc under the action of self-weight and load.At present,there is no mature system for slope soft soil embankment from theoretical research to design construction.Therefore,it is of great practical significance to study the stability of soft soil subgrade deformation for the development of high-speed railway in western China.In this paper,relying on the Yunnan section of Shanghai-Kunming passenger line,slope soft soil subgrade engineering characteristics and reinforcement plan are investigated systematically by means of theoretical analysis and numerical simulation.The results have been obtained as follow:(1)Based on the strength reduction method,the safety factor of subgrade under various influences such as different filling height,grade slope,relative slope difference between soft soil layer and hardened substratum,soft soil layer thickness and cohesion,internal friction angle are calculated through using numerical simulation.And the sensitivity of slope safety factor to various influencing factors is obtained by using grey correlation theory.(2)Based on the analysis of the deformation characteristics of the soft soil subgrade by numerical simulation,the deformation of the subgrade is obtained under different influence factors such as embankment settlement peak,differential settlement,horizontal slip deformation and differential horizontal slip.(3)Combination of shanghai-Kunming passenger line in Yunnan pile-net structure reinforcing slope soft soil subgrade engineering example,according to contrasting without reinforcement measures,only pile structure reinforcement,only cushion layer reinforcement and pile-net composite structure strengthening four kinds of working conditions,the deformation and stability of the slope soft soil subgrade are analyzed and the reinforcement effect of pile-net composite structure are evaluated.(4)Based on the analysis of the deformation and stability of slope soft soil road under the influence of multiple factors,some strengthen measures are put forward from different aspects in order to achieve economic applicable and reinforcement treatment of the optimization effect.