Prediction of cumulative settlement deformation in high-speed railway subgrades based on state evolution model
Long-term cyclic loading can result in the cumulative settlement of high-speed railway subgrades,and adversely affect track smoothness and compromising train operation's comfort and safety. The state evolution model was developed and solved using the finite difference method,considering the flowability of granular material and historical strain to predict the cumulative settlement of high-speed railway subgrades. A calculation method for predicting cumulative settlement under long-term cyclic loading was obtained. Experimental tests were conducted using scaled models subjected to graded and long-term cyclic loading. The results were analyzed to validate the rationality of the state evolution model in predicting subgrade settlement. Additionally,a three-stage fitting method was proposed,which involved fitting key parameters of the model using subgrade settlement data obtained from 0 to 10000 s of cyclic loading and predicting subgrade cumulative settlement from 10000 to 25000 s. The influences of initial state variables,characteristic strain,and characteristic parameters on the calculation results were thoroughly analyzed. The research findings are shown as follows. The time required for subgrade cumulative settlement to reach a stable value increase with the increase in load amplitude. The state variables are closely related to the magnitude of the load and increase with larger loads. The proposed method effectively reflects the cumulative strain of the subgrade under graded and cyclic loading,enabling accurate prediction of future subgrade cumulative settlement using existing data. Moreover,the accuracy of the prediction method is verified. It is found that larger initial state variables,characteristic strains,and characteristic parameters result in more remarkable flowability and accumulation strain rate of the subgrade. The study can provide a practical prediction method for the cumulative settlement and deformation of high-speed railway subgrade caused by long-term cyclic loads. The conclusions obtained from the research can serve as a reference for the design and deformation control of high-speed railway subgrades,demonstrating significant practical value and engineering significance.
high-speed railway subgradestate evolution modelsubgrade model experimentcyclic loadingcumulative settlement
万方数据
维普
