Effect of Hydro-Mechanical Hysteresis on Active Earth Pressure for Unsaturated Soils

Department of Geotechnical Engineering, Faculty of Engineering, Koya University, Koya KOY45, Kurdistan Region-F.Iraq. bestun.shwan@koyauniversity.orgbjnshwan1@gmail.com

Abstract

Stability analysis of retaining structures carried out at unsaturated conditions mainly dismissed the effect of hydraulic and mechanical hysteresis on the exerted active thrust. This paper reports a parametric study into the influence of hydraulic and mechanical hysteresis as well as soil types on active earth pressure carried out at low and high suction profiles to envision the pattern of the exerted active thrust for various simulated soils, from sands to clays. Generally, the numerical results exhibited a non-linear relationship between active thrust and suction. The influence of hydraulic and mechanical hysteresis and soil types on the active thrust was seen very significant. A reduction in P_a of 1.62 fold at s= 137.34 kPa, owing to the influence of hydraulic and mechanical hysteresis, was obtained when comparing two simulated soils; silt and clay. A soil with a wider capillarity range showed a higher positive effect of the hydraulic and mechanical hysteresis on the exerted active thrust.