Propagation of cohesive crack in unsaturated porous media by use of XFEM method Alireza Mokhtari, Ehsan Motevalli Haghighi and Behrouz Gatmiri E3S Web Conf., 9 (2016) 08010 Published online: 12 September 2016 DOI: 10.1051/e3sconf/20160908010