| The construction of mountain roads will have a certain impact on the mountains along the route,which can lead to serious geological disasters such as landslides.In order to prevent the occurrence of mountain road slope disasters,to protect the safe passage of the road and the safety of life and property of passing people and vehicles.This paper takes K1596+710～+880Tanmu Village Road soft rock high side slope monitoring project in Xixiang section of G210 National Highway in southern Shaanxi.Firstly,the deformation morphology and structural characteristics of the slope were analyzed by using the data from geological survey and monitoring on side,then the two-dimensional model of the slope was established by using Midas-GTSNX finite element analysis software,and the accuracy of the established model was verified by combining the monitoring data,and then the deformation and damage mechanism and evolution process of the soft rock slope were studied.On this basis,the engineering measures for slope treatment was studied and reasonable treatment plans were proposed.Finally,the stability of the slope after support was analyzed by a combination of numerical simulation and monitoring.The main research content and results of the thesis are as follows:(1)Through the site survey,the engineering geological conditions of the slope in Tanmu Village was mastered,and it was concluded that the rock and soil near the foot of the slope was exposed,the deformation was more serious,the maximum deformation thickness of the slope was about 36 m,the volume of the landslide was about 280,000 square meters,the composition material of the landslide body was dominated by the broken rock of the severe weathering zone,and it was a medium-sized thick layer traction rock slide.(2)The stability of the slope was monitored in real time by deploying monitoring equipment.By analyzing the monitoring data of crack meter 03,it can be seen that the accumulated displacement of the crack is 265.1mm,the average deformation rate is 2.88mm/d,and the tangent angle is 56.78°,at which time the slope enters the initial accelerated deformation stage;The analysis of the monitoring data of ZK5 and ZK6 slope measurement holes shows that the slope had a sudden change in displacement at 8-9m and 11-12 m,which is the location of the potential sliding surface of the slope;The analysis of rainfall shows that the infiltration of rainfall increases the deformation damage of the slope,but the impact on the slope is not real-time and has a certain lag.(3)A model of 240m×315m×1m was built with Midas-GTSNX software,and the displacements and equivalent plastic strains at ZK5 were simulated based on the MooreCoulomb criterion and the strength discounting method.The accuracy of the established model was verified by comparing and analyzing with the field monitoring data.(4)Midas-GTSNX was used to simulate the displacement and strain of the slope in the unsupported condition.The displacement deformation of the slope is characterized by large displacement at the leading edge,small displacement at the trailing edge,large displacement at the slope surface and small displacement at the depth.The maximum values of equivalent plastic strain,maximum shear strain and maximum principal strain of the slope are all at the location of the foot of the slope,forming a through sliding surface,and the slope is damaged in a creep-slip-tension crack mode.(5)The slope profile Ⅱ and profile Ⅲ are selected and the stability coefficient of the slope is calculated by applying the transfer coefficient method between 0.974 and 1.089,and the slope is in an unstable state.From the perspective of safety,economy and environmental protection,the selected slope support solutions are slope footing counter pressure,cut square unloading,anchor rods,anchor cables,anchor pipe frame beams,steel pipe piles and setting concrete retaining walls.(6)The stability of the slope after support is studied by using a combination of MidasGTSNX finite element software and field monitoring,and it is concluded that the slope has strong stability after support,and even under the action of seepage,the slope is not greatly affected;The comparison between the simulation results and the monitoring data verified that the monitoring results and the simulation results have a strong agreement. |
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