Activity Characteristics and Safety distance of Gaoliying Ground Fissure in BeijingHaigang Wang, Tongchun Qin, Haipeng Guo, Juyan Zhu, Yunlong Wang, Xisheng Zang and Xia LiE3S Web Conf., 79 (2019) 02009DOI: https://doi.org/10.1051/e3sconf/20197902009