Mao Xuesong

Moisture migration test investigation about subgrade filled with different soil

In order to study how soil influence water migration, which infiltrate subgrade, and the law of water migration, we use low liquid limit clay, silt and fine sand as research object. Real time water content in these samples without being destroyed were monitored. The dynamic observation is implemented by the moisture sensor and the data acquisition facility (6050X1 trase system).According to data, we can draw time-variety curve of the volume fraction of soil water content, curve of migration rate of wetting front and curve of infiltration rate. The results show that different water permeability and capacity of different soil influence seepage. Fine sand has the best permeability, low liquid limit clay is the worst, silt is between them. Each test-pieces upper soils water content has significant changes. Along with moisture infiltration, water content increase at first, then decrease, at last to stable.

Study on feasibility of the subgrade filled with weathered phyllite

To ensure the stability of the subgrade filled with weathered phyllite, we conducted a study on a new field test method of wetting deformation of the subgrade filled with weathered phyllite. On the foundation of the analysis on the physical and mechanical properties of the weathered phyllite, we evaluated the feasibility of the subgrade filled with weathered phyllite. We put up test section in the eastern Ankang section of the highway from Shiyan to Tianshui, took bearing plate field tests before and after immersion on the test road, analyzed the mechanism of the subgrade wetting deformation, got the result that wetting deformation is directly proportional to amount of water infiltration and resulted in the attenuation of bearing capacity of subgrade. Through the analysis of the results, we gave a further evaluation of the feasibility of the subgrade filled with weathered phyllite.