Study On Granite Residual Soil High Slope Stability And Support Scheme

Plot 19 of Guangzhou Xiangshan Lake Project is planned as 12 32-story high-rise buildings and supporting community roads.The north side is a mountain slope with a total length of 480m and a large slope.Construction of buildings requires manual excavation of the mountain to form an artificial slope with a height of 43m~65m.The special engineering geological conditions in Guangzhou area and the special nature of the soil layer,the overlying soil layer is mainly residual soil and strongly weathered granite.The average annual precipitation in this area reaches2000mm.Extremely strong convective weather often occurs in summer.During typhoons,the precipitation in some areas exceeds 400mm per hour,which has an important impact on the stability of artificial slopes.Therefore,the reasonable design of the artificial slope support scheme to ensure the stability of the artificial slope is of great significance to ensure the safety of high-rise buildings and related supporting facilities at the foot of the slope,as well as human life and property.In this paper,through field investigations and indoor tests,we refer to the relevant data of slope support in Guangzhou area,and use numerical simulation methods and limit equilibrium methods to carry out in-depth research on the support scheme and stability of the artificial slope,the main research The work and results achieved are:(1)Research on the engineering geological conditions of the site,and analyze and sort out the relevant data of the slope support scheme design in the granite residual soil area.At the same time,analyze the specific requirements of this project and the excavation limit range of the northern slope of the proposed building.The selection of support schemes and support parameters for similar projects in Guangzhou are summarized.Understand the specifications and requirements for slope engineering and support design.(2)The stability analysis of artificial slope was carried out.Using the numerical method FLAC~3DD software combined with the strength reduction method,the stress and strain state and stability of the artificial slope after the excavation limit were studied.At the same time,the stability of the artificial slope was analyzed using the limit equilibrium method Slope/W software to judge the artificial The stable state of the slope.(3)Aiming at the actual conditions of the artificial slope,a three-stage design method is proposed,that is,to optimize the slope shape first,and then to optimize the bolt parameters and anti-slide pile design schemes.(4)To optimize the slope shape of the excavation of the artificial slope,the optimization parameters are the slope ratio and the slope grade for optimal screening.Through the calculation method of FLAC~3DD software,the lateral displacement of the slope and the safety factor value are the results,and the various schemes are compared and analyzed,and finally the shape of the slope body is selected.(5)Parameters of slope anchor(cable)and anti-slide pile parameters are optimized.After selecting the shape of the slope body,the excavated slope must be supported by the slope body to meet the final safety requirements.By designing various simulation calculation schemes,the optimal anchoring angle of the anchor rod(cable),the optimal anchoring length of the anchor rod(cable),and the optimal length and spacing of the free section of the anchor rod(cable)in each grade are designed.optimization.Then the parameters of the anti-slide piles:the length of the anti-slide pile,the diameter of the pile,and the layout position of the anti-slide pile are optimized.Finally,an optimized plan for slope support is obtained.Final calculation and analysis,the design plan meets the specifications.