Method of Embankment Stability Analysis Taking into Account the Change in Undrained Shear Strength Caused by the Principal Stress Rotation in the Subsoil

This study investigates the selection of shear strength parameters for cohesive soil subsoils in the stability analysis of embankments in undrained conditions. It specifically examines how rotation of the principal stresses, induced by embankment construction, affects the undrained shear strength of the subsoil. Laboratory tests were conducted using a hollow cylinder apparatus on two types of cohesive soils to determine undrained shear strength at principal stress rotation angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90°. Analysis of the laboratory results, combined with numerical modelling, enabled the development of a new stability analysis method that incorporates the influence of principal stress rotation on undrained shear strength of subsoil.