A large-scale infiltration test on compacted expansive clay

The water transfer in a compacted expansive clay was investigated using a large-scale infiltration chamber (800 x 1000 mm in section and 1000 mm high). The large size of the soil column allowed burying the volumetric water content sensors (Theta Probe) without significantly affecting the water transfer and the soil swelling during infiltration. The soil suction was monitored along the soil height (every 100 mm) using various relative humidity sensors and psychrometers. The heave on the soil surface was also monitored using 15 displacement sensors. An infiltration test was performed on the compacted Romainville clay. Tap water was kept on the soil surface and changes in suction, volumetric water content were monitored for 338 days. The wetting front has reached the bottom of the soil column at the end of the test. The data from the simultaneous monitoring of suction and water content were used to determine the water retention curve and the unsaturated hydraulic conductivity using the instantaneous profile method.