Numerical Simulation of Subgrade Compaction under Influence of Water Content

Research purposes：As a new technology，intelligent compaction has been successfully applied to subgrade engineering，which brings great convenience to construction. However，research and practice show that the failure to consider the influence of soil moisture content has become one of the main reasons that restrict the accuracy of intelligent compaction test results. Based on the method of resistivity measurement of soil moisture content，the test electrode is simulated to be installed on the vibratory roller's vibratory wheel. In this paper，the subgrade analysis model of soil fluid solid electric coupling is established，and the deformation，electric field distribution and evolution laws of soil under different soil moisture content and exciting force conditions are studied. Research conclusions：（1）The coupling equations of soil stress field，moisture field and electric field in the process of subgrade intelligent compaction are derived，and the numerical analysis model is established using COMSOL software，which provides an effective means for the analysis and research of subgrade intelligent compaction.（2）The compaction deformation of subgrade is obviously affected by soil moisture content. The subgrade settlement increases with the increase of water content. Increasing the exciting force can increase the compression deformation of the subgrade，but it takes a long time to achieve stability.（3）When the excitation force is increased，the final water content of soil decreases. The soil with lower than the optimum water content is the least affected by the excitation force. The soil with higher than the optimum water content is most affected by the excitation force.（4）The resistivity decreases with the increase of water content. With the same water content of soil，the resistivity and influence range of soil under larger excitation force are smaller than those under smaller excitation force. At the optimum water content，the effect of the exciting force on the resistivity is minimal. （5）The research conclusions can provide theoretical and practical support for the development and promotion of intelligent compaction technology of subgrade. © 2024 Editorial Department of Journal of Railway Engineering Society. All rights reserved.