To explore the change law of cumulative plastic strain of loess subgrade under the cou-pling action of freeze-thaw cycles and traffic loads,remodeled loess in the Xining region was se-lected as the research object and a series of dynamic triaxial tests was performed using GDS bidi-rection dynamic triaxial test system.Effects of different freeze-thaw cycles,confining pressure,dynamic stress amplitude,and frequency on the cumulative plastic strain were investigated,and a prediction model for cumulative plastic strain with multiple factors was established by introducing fitting parameters.The results show that the cumulative plastic strain increases with the number of freeze-thaw cycles,and the growth rate slows down and stabilizes after six freeze-thaw cycles.Reducing the dynamic stress amplitude and increasing the confining pressure inhibits the develop-ment of cumulative plastic strain.The change in cumulative plastic strain with frequency is not possible at the initial stage of loading but becomes prominent with increasing vibration time,de-creasing with increasing frequency.Based on the evolution law of the cumulative plastic strain of samples,the power exponential and logarithmic models were used for fitting,and the latter had a good fitting effect.Considering the influence of the abovementioned four factors on the cumula-tive plastic strain,a prediction model for the cumulative plastic strain was established,and the predicted value was compared with the measured values to verify the feasibility of the model.The research results provide a theoretical reference for calculating the permanent deformation of loess subgrade in seasonally frozen regions.
cumulative plastic strain of loessfreeze-thaw cyclesdynamic stress ratiofrequencyprediction model
国家科技期刊平台
NSTL
维普
万方数据
