Study On Reinforcement Mechanism Of Anchor Pier Type Safety Netting System

In recent years,with the planning and construction of railway and highway in liangshan prefecture,many high and steep cataclastic rock slope reinforcement problems have been encountered.Due to the steep terrain in the prefecture,mudstone and sandstone are relatively developed,and severe weathering and denudation result in the shallow surface rock mass of this kind of rocky slope in a broken state,which has been locally unstable and dropped.Due to its surface damage point spread,coupled with high and steep slope,in the actual engineering often use SNS active defend the net for reinforcement,but such active defend the net structure of short anchor does not provide enough vertical slope method to the anchoring force,the direction of the traditional active defend the net structure and instability of the slope can't play the role of reinforced retaining wall,an urgent need to put forward and promotion is suitable for crushing high steep rock slope reinforcement measures.In order to improve the overall stability of the slope,this paper puts forward the pier-type active protective net structure,which is suitable for the reinforcement of the weathered rock slope in mountainous area.Numerical simulation,model test and theoretical analysis were used to study the anchoring effect and strengthening mechanism of the new reinforcement measures.In the numerical simulation part,three different slope models are established,which are ordinary active mesh reinforcement,prestressed anchor cable reinforcement and anchor pier type active protective mesh reinforcement.Finite difference software FLAC 3D was used to calculate the characteristics of deformation distribution,displacement distribution and stress distribution of the slope body of the three slope models,and the mechanical response law of the pier-anchored active protective net structure was summarized to verify the reinforcement effect of the new structure and reveal its action mechanism.According to the similarity theory,the prototype was reduced according to the similarity theory in the model test,and two slope test models were set: one was the slope model strengthened by anchor pier type active protective net,and the other was the slope model controlled by no anchorage measures.Each model reduces the geotechnical parameters by precipitation,and simulates the shallow surface instability and overall instability of the slope by precipitation in different parts of the slope.The reinforcement effect of pier-type active protective net is illustrated by comparing with the slope model without anchoring measures.At the same time,the axial force change and slope deformation of anchor pier-type active protective net are measured,and the numerical simulation comparison is made.Through the analysis and summary of the numerical simulation and model test results,the mechanical characteristics of the new type of pier-type active protective net are revealed.Combining the above results with theoretical analysis,the design proposal of anchor pier type active protective net is put forward,and the influence of shallow rock mass instability should be considered in anchor cable load design.The design method is summarized to provide reference for similar engineering design in the future.