Stability Analysis Of Guangzhou Gaobei Landslide And Optimization Of Anti-slide Pile Design

With the expansion and improvement of China's expressway network,the construction of expressways will inevitably destroy the original terrain and landforms,and the excavation of roads will cause the original balance of the mountain to be destroyed.Under the disturbance of mechanized construction,geological disasters caused by the resurrection of old landslides caused by engineering excavations,engineering landslides and unstable slopes are the key issues that must be faced during the construction of new highways.Relying on the landslide project along the Guangzhou Dapu to Chaozhou Expressway,this paper uses numerical simulation to analyze the stability of the landslide,the landslide failure behavior,and the control factors of anti-slide pile design.The following results have been achieved:(1)The topography,hydrology,climate,and lithology of the area where the landslide is located are systematically described,and the current status of the Gaobei landslide is analyzed.(2)Based on the monitoring data,an inversion analysis method of numerical simulation parameters based on on-site monitoring displacement is proposed(that is,the monitoring displacement value is approximately consistent with the landslide numerical simulation value,and the position of the sliding belt coincides),so as to determine that the model can accurately reflect the landslide.The current situation;monitoring data shows that the landslide is in a less stable state,the deformation of the leading edge of the landslide is greater than the trailing edge,the middle part is squeezed,and the nature of the landslide is judged as a traction landslide.Considering the deformation displacement,slip zone position,and plastic zone distribution of the landslide under three operating conditions,three numerical calculation models are established based on the typical cross section of the landslide.The average displacement values of the vertical route at the slip zone and the foot of the slope are extracted The landslide stability coefficient values under three operating conditions are compared and analyzed through data to reveal that the normal,heavy rain,and earthquake three operating conditions affect the landslide failure mode and stability change law.(3)According to the actual construction conditions of the landslide,through numerical calculation methods,five types of pile positions,five types of pile lengths,five types of pile spacing changes,and four types of row spacing changes calculation models(a total of 19 calculation models)were established and analyzed.Variations of the vertical slope direction displacement,maximum shear strain increment,plastic area distribution,and stability coefficient of landslides with different reinforcement methods.Through comparative studies,it is concluded that changing the pile position has the most obvious effect on landslide treatment during the landslide reinforcement treatment.The length,the distance between the piles and the distance between the rows of piles all affect the landslide treatment effect.Considering the economic and construction environment factors,It is determined that the No.2 pile position is the best pile placement position.The pile length is 24m?27m,the pile spacing is 4m?6m,and the pile spacing is 15m?20m.(4)The original landslide treatment design scheme was researched,a numerical calculation model of the original design scheme was established,and the original design scheme was evaluated based on the calculation results.It was concluded that the anti-slide pile cannot fully function because the pile placement position is not the optimal pile position.Aiming at this problem and combining the conclusions of anti-sliding pile reinforcement obtained in this paper,a total of 9 numerical models of 3×3 are established.The cross-analysis of the reinforcement effect when the row spacing and the length of the back row are changed.The change of area and stability coefficient finally show that when the pile length is 27m and the distance between rows of piles is 20m,the landslide treatment effect is the best one among the nine comparison schemes.This conclusion can be used for reference in construction design and can be used as a reference for similar projects in the local area.