ANALYSIS OF DYNAMIC CHARACTERISTICS OF LOESS SUBGRADE UNDER VEHICLE LOAD

Aiming at energy-saving and environment-friendly roads, many low embankment design schemes have been adopted, resulting in some loess roadbeds being within the influence of traffic loads, and the status of roadbed subsidence deformation is apt to occur. Starting from the perspective of dynamic triaxial tests, this paper investigates the response of dry density, confining pressure and frequency to the dynamic properties of subgrade soil under dynamic load. The study shows that the dynamic elastic modulus of subgrade soil increases with the increase of dry density, confining pressure, and loading frequency. The greater the dynamic elastic modulus of soil, the smaller the corresponding damping ratio. In the design scheme of low embankment, the settlement caused by vehicle load during operation can be reduced by appropriately increasing the dry density of the loess subgrade. At the same time, the lower limit of the frequency range of the vehicle dynamic load should be used in the subgrade design.