Stability Analysis Of Zhenxiong Slope And Reinforcement Optimization Of Anti-slip Pile

Slope stability is an important research topic concerning people’s livelihood safety and social development.A correct analysis and research on slope stability is of great practical significance to strengthen geological disaster prevention and guide engineering and economic construction.Rainfall is the main natural factor that induces slope instability damage.The infiltration of rainwater leads to the weakening of soil shear strength,which causes landslide instability disasters in engineering construction and daily life,and when the slope faces the risk of instability and sliding,it is often necessary to carry out reinforcement management.Zhenxiong power plant access road slope geological conditions are complex,the soil strength parameters are low,coupled with continuous rainfall and high water table of the dual role,resulting in the slope body is unstable decline state,seriously affecting the power plant site and access road safety.In order to ensure the safety of the power plant site and people’s lives and property,the stability analysis of Zhenxiong slope and the reinforcement optimization study of anti-slip pile were carried out based on the secondary development of FLAC3 D.To this end,the paper focuses on the following studies:(1)Considering the steady-state seepage,a numerical model of the slope is established based on the engineering geological data,and the natural slope is calculated based on the strength reduction method of fluid-structure coupling analysis.The results show that the safety coefficient of natural slope under steady state seepage is 1.07,and the potential slip zone appears at the junction of bedrock and weak soil layer,and localized shear deformation is generated,and the slope is in an unstable state.(2)Based on the FISH language,the program is written for secondary development,which realizes the transient seepage processes such as slope rainfall infiltration,flow boundary conversion and runoff,and reveals the influence of different rainfall intensity and rainfall time on slope stability.The results show that: with the increase of rainfall intensity,the pore water pressure of slope soil increases,the effective stress decreases,and the slope safety coefficient decreases from 1.07 to 0.89 under heavy rainfall conditions,and the saturation zone appears on the slope surface;at the early stage of rainfall,the change of slope safety coefficient is gentle,and as the rainfall continues,the change range of pore water pressure gradually increases,and the infiltration depth also increases,but the pore water pressure from the surface layer to the infiltration line gradually decreases.However,the change of pore water pressure from the surface layer to the infiltration line gradually decreases,indicating that the infiltration capacity of rainwater decreases with the increase of rainfall time and depth,and when the rainfall intensity exceeds 20mm/d,the safety coefficient of the slope decreases to below 1.0 after 3 days of rainfall.(3)Considering the results of rainfall analysis,the stability analysis of the slope of the whole project is carried out.Based on the principle of total stress,a numerical model of largesize slope is established,and the natural slope stability analysis is carried out by the strength reduction method based on the abrupt change of nodal displacement characteristics.The safety coefficient of natural slope is 0.96 calculated by the nodal displacement abrupt change method,and a through plastic zone is generated from the top to the foot of the slope,and the slope is in an unstable state by comprehensive analysis.(4)Based on the large-size numerical model,the anti-slip pile reinforcement location,pile spacing,pile length and pile-soil contact surface parameters were optimized and analyzed to obtain the optimal design parameters.It is found that: the optimal location of anti-slip pile is located at the lower part of the slope,the safety coefficient is increased from 0.96 to 2.35,the maximum horizontal displacement of the slope is reduced by 98%,and the anti-slip pile has obvious isolation effect on the plastic zone;with the gradual decrease of pile spacing,the soil arch effect becomes more and more obvious,and the optimal pile spacing is 3 times of pile diameter;with the gradual increase of pile length,the safety coefficient of the slope gradually increases,and when the pile length reaches 14 m,the safety coefficient is more stable,and the optimal pile length is 14 m.After the pile length reaches 14 m,the safety factor is more stable,and the optimal pile length is 14m.