Study On Subgrade Stability Under Heavy-load Traffic In Xinjiang Area

At present,highway construction has maintained a strong momentum of development in Xinjiang area,as the main part of goods transportation,road transportation appears gradually overloading,big flow and channelized traffic phenomenon.Overloaded trucks and overloading vehicles increase sharply,traffic flow increase by a wide margin,that makes the settlement of high embankment under the action of load slope sliding and disease problem more and more serious,the stability of highway subgrade remains to be improved.Under the action of heavy traffic load,the subgrade top surface compressive stress increases gradually,the subgrade slope stability gradually decline,these are the reason of insufficient stability of subgrade.Therefore,this paper put forward the study on subgrade stability under heavy-load traffic in Xinjiang area,the construction and development of highway in Xinjiang area is of great significance.Firstly,through the investigation into heavy-load traffic subgrade using situation and disease characteristics of Xinjiang mining area resources road,Based on Xinjiang mining area resources distribution,traffic volume distribution,vehicle axle load distribution,and other aspects,which were analyzed furtherly,and concluded that heavy-load subgrade disease causes and mechanism in Xinjiang area,the Xinjiang area heavy-load traffic regional distribution was put forward,which laid the foundation for selecting representative subgrade structure foundation in the area of heavy-load transportation and heavy-load subgrade stability analysis.Secondly,subgrade slope stability analysis method and the subgrade soil constitutive model,yield criterion,flow rule and hardening rule was systematically introduced,typical subgrade structure and its related material parameters in Xinjiang area were chosen,limit equilibrium method and finite element strength reduction method were respectively used to compare and analyze subgrade slope stability coefficient and instability destroy mode,and concluded that subgrade slope instability rule under the action of load,which provided important reference basis for determining final subgrade stability analysis method.Thirdly,the influence on subgrade slope stability under the action of the load from control index was studied,the influence of the subgrade soil strength index,stiffness index,geometry size,soil density on subgrade slope stability coefficient under quasi static load were analyzed respectively,which for gain the intrinsic relationship between the relevant control indicators and subgrade slope stability coefficient under the condition of quasi static load,and the various control indicators of the effect on the coefficient was in-depth studied at the same time.Finally,based on the investigation and analysis of the representative subgrade structure and axial load of heavy-load traffic load in Xinjiang area,functional finite element software FLAC^3D was used,the influence on subgrade slope stability from different load factor was numerical simulated,the different load size,load length,load width and load location influence on three-dimensional subgrade slope stability was analyzed theoretically,concluded the changing rules of subgrade slope stability coefficient and the critical sliding surface under different load factors.