Experimental hydraulic fracturing of Berea sandstone under triaxial stress state Hazem Mubarak, Roshan Saji, Goulong Zhu, Rita Sousa, Mohamed Sassi and Rashid K. Abu Al-Rub E3S Web Conf., 205 (2020) 03014 Published online: 18 November 2020 DOI: 10.1051/e3sconf/202020503014