Experimental Investigation of Soil-Atmosphere Interaction in an Instrumented Embankment Constructed with Two Treated Clays

This paper discusses the field monitoring of an experimental embankment divided into two symmetrical instrumented sections constructed with two clays treated with lime and/or cement in the northeast of France. The soil-atmosphere interaction is investigated in the monitored embankment. The field instrumentation included spatial and temporal changes of the soil suction, moisture, and temperature at predefined locations within the embankment, as well as measurements of meteorological data, collected from April to November 2011. The data show similarities in the suction daily variations trend in the two treated clays. Maximum changes in suction occur near ground surface. Even at the location of -0.75 m from the slope face the interchange of water between the atmosphere and the ground was observed in the daily soil suction measurements. No significant hydrologic response of the soils to rainfall was observed during the period of water deficit. The rainfall events showed a significant effect on the soil suction changes in the initial period of water surplus after a long period of water deficit. The comparison of the period of water deficit observed in the responses of the mean monthly suction and moisture measurements in the treated soils and the one estimated by simple water balance models based on standard meteorological observations in the region indicate that there is an overall qualitative agreement between the modelling and observational results.