Analysis on the Moisture Migration of Subgrade Soil with Constant Temperature Condition
XU Jian,NIU Fu-jun,NIU Yong-hong and HOU Zhong-jie
DOI:10.11835/j.issn.1674-4764.2011.04.018
Received December 28, 2010,Revised , Accepted , Available online July 01, 2015
Volume ,2011,Pages 113-119
- Abstract
A moisture migration test for unsaturated clayey loess along Shenyang-Haerbin Express Railway for Passenger Line was carried out to investigate the water movement of soil in an open system with constant temperature condition.It is shown that moisture transfer is mainly caused by matrix potential and gravitational potential energy.The water content by volume gradually decreases from the bottom to the top of specimen.Over time the capillary water height increases by the power function and eventually reaches a stable value.The water flux decreases with time by the logarithm function.Based on the model test,finite element method is adopted to simulate the moisture transfer process in soil under isothermal condition.It is found that the numerical results are in good agreement with the experimental data.The model is thereby used to simulate the rise of groundwater in the subgrade soil.During the whole process of moisture movement,pore water pressure gradually decreases from the bottom to the top of sample.The rapid change of pore water pressure in the early process contrasts with slow change in the late process.The pore water pressure has a linear change along the specimen when the seepage reaches steady state.