Undrained cylindrical cavity expansion/contraction in stiff clays using a two?surface plasticity model

This paper presents a semi-analytical solution of undrained cylindrical cavity expansion/contraction problem using two-surface plasticity model for natural stiff clays from the view point poromechanics. The present reduces classical boundary into group seven first-order ordinary differential equations via an auxiliary independent variable ? under conditions. It strictly follows premise constant soil mass (CSM). Meanwhile, volume (CSV) is used comparison. shows that CSM assumption paramount importance in developing solutions high stress condition, while CSV induces non-negligible errors effective and pore pressure distributions. Based on CSM, extensive parametric studies are undertaken to investigate effects key parameters components distribution, excess expansion curves. could be useful dealing with geotechnical petroleum engineering problems involving or soft claystones. application Praclay Gallery excavation Boom clay well demonstrates validity solution.