1. Key Laboratory of Geotechnical & Underground Engineering of Ministry of Education; Tongji University; Shanghai 200092 China
2. Department of Geotechnical Engineering; Tongji University; Shanghai 200092 China
3. Department of Civil and Environmental Engineering; University of Houston; Houston TX 77204 U.S.A.
4. Itasca Microseismic and Geomechanical Evaluation; Stafford TX 77477 U.S.A.