Dynamic Triaxial Test Study On The Geogrid Reinforced Soil

With the large-scale construction of high-speed railway in China,the requirement to the subgrade will be higher and higher,the research about the subgrade under the traffic load also has important significance.In this paper,with gravel soil in Dalian area as reinforcing filler,with geogrid as reinforced materials,medium static and dynamic triaxial apparatus was used to dynamic triaxial orthogonal test to analysis of the reinforced soil response under different frequency,dynamic stress amplitude,reinforced layer and confining pressure,and get the time history curve,the stress-strain curve,the dynamic elastic modulus curve about the reinforced soil under dynamic action.,and analyze some useful research results:1.The change of stress frequency relates to the vibration frequency,the higher vibration,the faster stress changes,the lower vibration,the slower stress changes.2.As the vibrations continue to increase,the axial strain increment becomes slower,the axial strain becomes stable.3.The relationship between dynamic stress and dynamic strain is sclerosis type,the bigger dynamic stress,the bigger dynamic strain is.4.Confining pressure is the biggest factor that influence the strength of reinforced soil,reinforced layer is the second condition,dynamic stress amplitude is the last condition,frequency is between dynamic stress and reinforced layer.To reinforce one layer to improve the effect is more significant than two layers.Dynamic stress amplitude affects the dynamic elastic modulus of the soil is the largest,the second condition is reinforcement layers,the frequency is greater than the confining pressure.5.By software FLAC^3D,to establish the Mohr-Coulomb constitutive model,to analysis the stress of reinforced subgrade under cyclic loading.