Consolidation analysis around cavity expansion in presence of vertical drains

¹ Univ.de Carthage, Institut Supérieur des Technologies de l’Environnement de l’Urbanisme et de Bâtiment, 2 Rue de l’Artisanat Charguia 2 - 2035 Tunis, Tunisia
² Univ. de Tunis El Manar, Ecole Nationale d’Ingénieurs de Tunis, LR14ES03-Ingénierie Géo-technique, BP 37 Le Belvédère, 1002 Tunis, Tunisia
³ Univ. de Tunis El Manar, Ecole Nationale d’Ingénieurs de Tunis, LR14ES03-Ingénierie Géotechnique, BP 37 Le Belvédère, 1002 Tunis, Tunisia, Setec International 42-52 Quai de la Rapée Central Seine Building 75583 Paris Cedex 12. France

^* Corresponding author: zeineb.bensalem@gmail.com

Abstract

As a ground improvement technique, the new method composed by a cylindrical cavity expansion (CCE) combined with vertical drains (VD) greatly accelerates the consolidation of soft soil. In fact, the cylindrical cavity applies a radial displacement in the soil. Excess pore pressures will be consequently generated and the consolidation process will occur at the vicinity of the cavity wall. The dissipation of excess pore pressures can be enhanced in presence of VD installed at a radial distance rd from the center of the cylindrical cavity. Because of CCE installations in soft soil, surrounding soil properties are altered in such a manner that horizontal permeability of the soil in the smear zone reduces. The purpose of the present paper is to investigate the subsequent consolidation around CCE using the Finite Difference Method (FDM) by taking into account the CCE installation disturbance. Parametric analysis aimed to investigate the effect of the extent of the disturbed zone, the soil permeability reduction in the smear zone on the rate of consolidation around CCE.