Research On Stability Of High Fill Embankment Slope With Xigeda Strata

The research of the embankment slope stability which use special soil as the embankment filler is always an important subject in geotechnical engineering. Some practical engineering have adopted some types of special soil as the embankment filler at present. However, the stability studies of the high embankment which used special soil is not enough, especially in the field of using Xigeda strata as the embankment filler in the railway embankment and the influence of reinforcing the slide-resistant pile to the stability of high fill slope with Xigeda strata.There is no systematic study and summary on its physical and mechanical properties and engineering properties.This paper based on the construction of Chengdu-Kunming Railway Panzhihua South Railway Station, on the background of the China Railway Eryuan’s study on "the key technology of ultrahigh embankment and deep cutting engineering in Xigeda strata", started from the existing slope stability theory and slide-resistant pile mechanism, choosing the typical embankment cross-section, building model of high embankment in Xigeda strata with FLAC3D program. Firstly, this paper makes comparative analysis of some slope stability factors in high embankment with original Xigeda strata and reinforcing the slide-resistant pile, the factors include the slope’s horizontal displacement, subsidence and safety factor of the high embankment model with Xigeda strata. Secondly, choosing to use slide-resistant pile, in this case, compared horizontal displacement, subsidence and safety factor of models of the piles slide-resistant between10different pile location and5different pile spacing, then it obtains the optimal pile’s space location. As to the optimal pile’s space of the high embankment model with Xigeda strata,obtaining the embankment’s horizontal displacement,subsidence and the change rules of pile’s stress and horizontal displacement after backfill,in order to make a comparative analysis with the actual monitoring results.According to the analysis result of data simulation, it is concluded that high original embankment without reinforcement in Xigeda strata will be instability.As the pile near the centerline of the embankment,subsidence and horizontal displacement increase, safety factor first increases and then decreases,the best optimal pile’s space location is52m from the centerline of the pile to the centerline of the embankment.Pile spacing have less impacts on pile’s horizontal displacement and subsidence. The bigger the pile spacing,the subsidence and horizontal displacement bigger and the smaller the safety factor. the best pile spacing is6m.For the design pile location of DK591+160embankment section simulation,The horizontal displacement and subsidence will increase with the embankment height. The stress on the pile first increases and then decreases with the depth of pile increase.The pile’s horizontal displacement will increase with the depth of pile, falling from the pile top to pile bottom.