A simple model for the water retention curve of compressible biocemented sands using MIP results

Abstract

Biocementation treatment consists in using bacteria or other biological agents to promote the precipitation of calcium carbonate (biocement) in the soil pores. When used in slopes for protection against surface erosion, this treatment creates a stiff and strong pervious cover, allowing infiltration necessary to reduce water runoff. The knowledge of the water retention properties of biocemented soils is fundamental knowledge for modelling infiltration but it may not be easy. In this paper the water retention curves of two different treated sands were estimated using a simple model obtained from pores size distribution measured using mercury intrusion porosimetry (MIP) tests. The model proposed considers volume changes of the soil during the MIP test due to the compression of air trapped in the voids. The WRC derived from the MIP tests fits well the points measured using a water dewpoint psychrometer, however it is not possible to check curve fitting below the residual water content due to lack of experimental data.