Hydraulic hysteresis of natural pyroclastic soils in partially saturated conditions: experimental investigation and modelling

Abstract In many geotechnical applications, especially in the study of weather-induced landslides, a reliable soil hydraulic characterization unsaturated conditions is required. Currently, experimental techniques that neglect hysteresis represent greatest limitation to landslide forecasting. this paper, procedure obtain an on natural pyroclastic samples proposed and verified. The approach enables evaluation properties along main drying path wetting/drying cycles fully quantify effects hysteresis. Pyroclastic collected at test site Mount Faito Campania region (southern Italy) were tested. investigation consisted sequence testing phases: constant-head conductivity test, forced evaporation followed by several wetting–drying cycles, pressure plate apparatus. hysteretic model Parker Lenhard (1987) was adopted fit data, while inverse modelling tests allowed derive parameters. Therefore, wetting branches response from any reversal point reproduced with model, which suitably described behaviour under all paths.