Stability Analysis And Prevention Measures Of High Cutting Slope In Nalao Section Of Tianxi Expressway

In recent years,the pace of highway construction has been significantly accelerated due to the increase in national infrastructure construction,but the consequential instability of highway slopes has gradually become prominent,which has seriously affected the development of highway traffic and personal safety,and has aggravated the geological situation.The deterioration of the environment and the safety hazards caused by the stability of the slopes have seriously restricted the normal operation of the road.At the same time,with the continuous increase of large-scale projects,the problem of slope treatment has become more and more serious.In the current highway construction,the treatment of high cutting slopes has become a particularly important engineering process.Solving this technically complex and difficult major project has a more positive impact on the safety and stability of the transportation industry.When I arrived at Tianxi Expressway in April 2019,it was during the flood season in Guangxi,and the rainfall was extremely frequent.After multiple rains,the slope instability occurred,which seriously affected the normal traffic of the road.Research on slope stability and prevention measures.This paper selects the high side slope on the right side of the Nalao section of the expressway as the research object.On October 30,2020,the slope of this section was unstable due to heavy rainfall during the initial support process.The following research was carried out:(1)According to the on-site survey and combined with its basic data,the hydrological and geological conditions of the high cut slopes studied are described,and the physical and mechanical parameters of the rock mass are determined.(2)Performing risk assessment on the slope before construction to determine its risk level.The “Guidelines for the Construction Safety Risk Assessment of Highway Cutting High Slope Projects” were used for the assessment.In the overall risk assessment,the slope scale,rock and soil properties,construction difficulty and other factors were comprehensively considered,and the risk level was rated as level III(high risk).To this end,a special risk assessment was carried out for it,based on its risk characteristics,security risk identification and analysis,major risk sources were assessed,and major risk sources were quantitatively evaluated,It is concluded that the construction risk level is high risk(level Ⅲ),and security risk control measures were proposed.(3)The basic principle of Flac3 D software calculation and the basic concept of strength reduction method are introduced.Flac3 D software was used to excavate the instability section of the high side slope of the Nalao section of the road establishing retaining walls,first support,rainstorm conditions,and natural conditions and two prevention measures.Numerical simulations were carried out on the rainstorm conditions,and the two prevention measures were compared.Finally,the first option was selected to be applied to the engineering practice,and the simulated values were compared with the actual monitoring data.The changed law of stress,displacement,and shear strain increment is analyzed,and the position of the sliding surface of the slope and the displacement of the supporting structure are analyzed.Finally,this paper summarizes the full text and make a prospect.