Study On Stability Judgment Standard Of Highway Soft Soil Foundation Embankment Construction

When constructing highway embankments on soft soil foundations,engineering problems such as stability and settlement are often encountered.During the construction of the embankment,the stability and settlement of the subgrade are related to the construction period,investment funds and operations of the highway.According to the current current standard “Technical Specification for Design and Construction of Highway Soft Soil Foundation Embankment”(JTG / T D31-02-2013),the standard for determining the stability of soft soil roadbed is displacement rate 5mm/d,sedimentation rate 10~15mm/d.According to the actual engineering experience,many monitoring indicators have not exceeded the control standards,but the roadbed is unstable or the monitoring indicators are greatly exceeded,and the roadbed is not damaged.In view of the above situation,this paper seeks to explore new stable judgment criteria and conducts the following research.(1)According to the settlement composition of soft soil roadbed,the settlement composition of the subgrade construction period = main consolidation settlement +instantaneous settlement is analyzed,and the settlement rate of the construction period = main consolidation settlement rate + instantaneous settlement rate is obtained.(2)Comparing the estimation method with the total stress finite element analysis method,the feasibility of using the finite element software Midas GTS NX to calculate instantaneous settlement and horizontal displacement is confirmed.(3)The finite element software Midas GTS NX was used to simulate the soft soil foundation embankment construction,and the effects of soft soil depth,soft soil modulus,embankment width and fill rate on foundation deformation were considered respectively,and the relationship between deformation and influencing factors was obtained.,propose new standards.(4)The engineering test data of the slip roadbed in the "Soft Soil Foundation Test Research Collection" is compared with the standard calculation results presented in this paper,and the feasibility and practicability of this standard are verified.