Dynamic Response Analysis Of Low Embankment On Saline Soft Soil Ground Under Traffic Loads

This paper relies on Tonggulegenaer to Eerkehasha highway project,which is located in the Tengger Desert.In the desert area,sand dunes,salt marshes,mountains,lakes,marshes and plains are staggered.And the project line passes through the lake basin,where salinized soft soils are mostly distributed.In addition,the highway of desert area is mostly designed for low embankment,affected by traffic load even more.In this paper,the distribution of saline soil along the highway is studied by field investigation and indoor experiment,and the zonal map of saline soil along the line is obtained.Through the establishment of the test road,the settlement of the subgrade under the construction period and the operation period is carried out.The results show that the application of the aeolian sand and the gravel meets the standard requirements and the settlement is stable.According to the actual situation of this project,the load is simulated by the simple harmonic load,and the movement of the load is realized by moving the harmonic load and distributing the belt.The three-dimensional embankment model is established under the simple harmonic load.The dynamic response of the roadbed under the aeolian sand replacement,the vehicle full load and the vehicle speed 40 km/h is numerically calculated.The vertical displacement and stress along the depth changed rules is obtained,also,the dynamic time curve is obtained,and the depth of influence of the dynamic response of the subgrade is about 1.9 m.Compared with the above ground for the depth of the field,the the treatment program of test section is reasonable.Considering the factors such as overloading,parameters of foundation reinforcement and driving speed,the single factor variable control is used to calculate the dynamic response of roadbed under different working conditions.When overloading,the depth of influence of the dynamic response of the subgrade is much higher than 1.9 m of the full load.According to the vertical plastic strain zone,it can be seen that overloading may cause great damage to subgrade and slope.After the gravel treatment,the deformation characteristics of the upper subgrade are improved from the vertical displacement change.At different speeds,the time and amplitude of the dynamic load are the main influencing factors of the dynamic response under different vehicle speed conditions.The peak value of the vertical displacement and the equivalent plastic strain are mainly affected by the time.the increase of vehicle speed causes a larger dynamic load amplitude,which leads to the increase of vertical dynamic stress fluctuation,and the vertical plastic strain gets greater.Therefore,the impact of high-speed vehicles on the roadbed dynamic response is much greater than the low speed.Compared with the existing research results,the test results show that the finite element numerical calculation results of model in this paper is reliable,the conclusion of model and the regularity of the test section can be used for salinization of embankment on salinized soft soil foundation in other similar areas and design or construction of low embankment reference.