Numerical Study On Support Scheme Of Deep Excavation Cutting Slope In Complex Stratum Of 310 National Highway

The problem of deep excavation slopes becomes more and more obvious in road construction.Based on the background of the newly constructed 310 National Highway Project in Sanmenxia City,this paper uses a numerical simulation method to analyze the stability of the permanent slope of a deep excavation in a complex stratum under excavation without support;the three support schemes proposed are compared and selected The best support scheme;through the analysis of slope displacement,bolt axial force,equivalent plastic strain and stability,the process parameters of the support scheme are optimized.The main work content and conclusions are as follows:(1)According to the engineering situation,the characteristics of the engineering slope were analyzed;combined with the impact of the engineering damage on the surroundings and the requirements of the code,the safety level of the engineering slope was determined to be Grade 2 and the stability coefficient of the slope was required to be 1.3.(2)Analyze the deep excavation slope of the unsupported deep excavation to be excavated and find that the stability coefficient is small and the maximum horizontal displacement is large,which does not meet the requirements of the specification;through the study of three supporting schemes,the slope displacement is found Obviously reduced,the stability is significantly improved.(3)Three support schemes are proposed,namely soil nail support,anchor frame beam support and anchor anti-slide pile support.Through comparative analysis,it is found that the support effect of the anchor frame beam is the best,and It has great advantages in terms of construction difficulty and engineering cost.(4)The anchor angle,prestress size,length of anchoring section and vertical spacing of anchors supported by the anchor frame beam are optimized,and it is found that the slope stability is positively related to the support angle and the prestress size The relationship is inversely related to the length of the anchoring section and the vertical spacing.(5)The anchor parameters are determined.When the angle of the anchor is 10°,the prestress is 160 kN,the length of the anchoring section is 10 m,and the vertical spacing of the anchor is 3m,the supporting capacity of the anchor frame beam is in the slope To get the most out of it.