Study On Stability Of Rock Slope With Weak Interlayer And Anti-slide Pile Retaining Effect

In slope stability analysis,there are difficulties in calculation and analysis due to the discontinuity,polyphase and variability of rock mass.The weak interlayer is a thin layer in the rock mass.Its mechanical strength and deformation modulus are lower than those of surrounding rock,so it has a great influence on the stability of slope.Therefore,it is particularly important to study the influence of weak interlayer on displacement zone,plastic zone and safety factor of slope.In this paper,the slope displacement and reinforcement stress of anti-slide pile are used to establish ABAQUS numerical model,and the stability of slope with weak interlayer under different working conditions is studied based on the landslide control project of a fast passage in Zhengzhou.The main research contents are as follows:(1)According to the landslide situation,the field experiment method is put forward and carried out.Put forward the field experiment method according to the landslide situation.The level and total station were used to observe the surface displacement of the slope.The reinforcement stress in the anti-slide pile is measured by vibrating string reinforcement stress meter and the bending moment of the internal section of the anti-slide pile is calculated by the principle of double reinforcement normal section bending.The measured bending moment is far less than the design moment,indicating that the reinforcement effect of the anti-slide pile is remarkable and the safety margin of the anti-slide pile is large.(2)ABAQUS is used to study the stability of slope with weak interlayer under different working conditions.The finite element analysis software ABAQUS is used to analyze the stability of slope with weak interlayer before slope cutting,after slope cutting and after reinforcement,and to analyze the variation law of its stress field and displacement field.Study on slope stability under rainfall infiltration: The results show that when rainfall penetrates into the soft interlayer,rainwater will collect in the upper part of the soft interlayer and change the seepage path of rainwater,resulting in a "V" shaped pore pressure curve.The slope stability decreases after rainfall infiltration.After 72 h of continuous rainfall,the slope horizontal displacement U1 increases by 0.352 m,the vertical displacement U2 increases by 0.387 m,and the slope safety factor decreases by 0.31.(3)The influence of different parameters of weak interlayer on slope stability is studied.Different thickness(2m～4m)and inclination Angle(24°～36°)of weak interlayer are used for numerical analysis to study the influence of weak interlayer thickness and inclination Angle on slope displacement and stress field.The results show that slope displacement increases with the increase of weak interlayer thickness and inclination Angle,and the safety factor becomes lower and lower.(4)ABAQUS was used to simulate the slope stability of anti-slide pile under different parameters.The slope numerical model is established,considering the pile position,pile length and pile spacing of anti-slide piles,and the optimal reinforcement scheme of anti-slide piles is proposed through the numerical simulation results.The results show that the slope stability coefficient increases first and then decreases when the anti-slide piles are arranged from the first platform to the fourth platform,and reaches the maximum at the second platform.When the pile grows to 23.4m,increasing the pile length has little effect on improving the slope safety factor.When the pile spacing is between 5m and 7m,the displacement is large,and the anti-slide effect of anti-slide pile basically disappears when the pile spacing reaches 7m.After analyzing the displacement and safety factor,the optimal pile spacing is 5m.