Numerical Simulation Analysis Of The Stability And Protection Of Bainigou Creeping Slope

The terrain and geology of China are complicated,with the hilly area accounts for about 2/3 of country’s land,forming a large number of natural slopes.Therefore,there is a variety of disaster,such as landslides,collapses,debris flows,etc.China is also one of the countries with the most serious landslides in the world.As a large amount of rock and soil mixture pours down when landslides occurred,it has a huge destructive force and poses a great threat to the safety of people’s lives and property.The economic development of mountainous areas is based on convenient transportation Restricted by terrain conditions,the new highway will inevitably be affected by the stability of mountain slope.There are many factors that induce the instability of mountain slope,such as rainfall,earthquake,artificial excavation,etc.Among them,rainfall,earthquakes and other natural phenomena are unavoidable.Therefore,it is of great significance to analyze the stability of the slope,and to reinforce the slope that will cause damage.In this study,FLAC program was used to simulate the Bainigou creeping slope.The stability of the slope under natural,rainfall and earthquake conditions was analyzed,and we put forward three different reinforcement schemes according to the failure characteristics of the slope.Then,the slope with different support schemes was simulated.Finally,the treatment effect was discussed by analyzing the internal force response of the protective structures.The specific research contents,methods and results are as follows:(1)According to the geographical location,hydrogeological conditions and human activities of the slope area,we know that there is a weak mudstone layer in the rock stratum of slope,which is the ultimate cause that make slope instability.Secondly,the artificial excavation and earthquake further contributed to the sliding of the slope.According to displacement monitoring results,the slope was in the creep stage at present.The shear crack at the front edge of the slope was not clear,and the cracks on the back edge were large.We judge that the sliding surface was not connected.(2)According to the engineering geological profile,a two-dimensional numerical model of Bainigou slope was established by FLAC program,and the reliability of the model was verified by the monitoring data.Based on this,the stability of Bainigou slope under natural,rainfall and earthquake conditions was simulated.By analyzing the displacement,and stress-strain of the model,it can be concluded that the maximum values of stress and maximum shear strain increments occurred in the middle of the sliding surface under three conditions,and the stability of the slope was the worst under seismic condition.The calculation results can provide reference for support scheme.(3)According to the deformation characteristics of slope,three different protective structures were proposed,which were double row anti-slide pile,anchor cable anti-slide pile and anchor cable,pile-plug structure.The structural units of the FLAC calculation program was used to simulate the protected slope under natural and earthquake conditions.By comparing and analyzing the differences in the treatment effects of different support schemes,it was concluded that the pile-plug structure had the best effect,followed by anchor cable and anchor cable anti-slide pile,and the anti-slide force provided by double row anti-slide pile was insufficient.Then,the response of the reinforced structure was analyzed.The results showed that the double row anti-slide piles can share the sliding force,but the sliding force for the anti-slide piles was still relatively large,which will cause that the pile top pushes the surrounding soil downwards.Anchor cable reinforcement can provide the greater anti-sliding force,and reduce the downward slide trend of the slope.Anchor cable with prestressing can effectively restrain the displacement of the pile top and improve the bearing capacity of the pile shaft.The inner force distribution using the pile-plug structure was reasonable,and it had better integrity,which played a beneficial role on anti-sliding.