Comprehensive assessment on dynamic roof instability under fractured rock mass conditions in the excavation disturbed zone

Xing-ping Lai1,2,3) ,Fen-hua Ren2) ,Yong-ping Wu1,3) ,and Mei-feng Cai2) 1) Energy School,Xi’an University of Science & Technology,Xi’an 710054,China 2) School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China 3) Key Laboratory of Western Mine & Hazard Prevention,China Ministry of Education,Xi’an 710054,China

摘 要：The damage process of fractured rock mass showed that the fracture in rocks induced roof collapse in Yangchangwan Coal Mine,China. The rock mass was particularly weak and fractured. There occurred 6 large-scale dynamical roof falls in the excavation disturbed zone（EDZ） with the collapsing volume of 216 m3. First,the field detailed geological environment,regional seismic dynamics,and dynamic instability of roadways were generally investigated. Second,the field multiple-index monitoring measurements for detecting the deep delamination of the roof,convergence deformation,bolt-cable load,acoustic emission（AE） characteristic parameters,total AE events,AE energy-releasing rate,rock mass fracture,and damage were arranged. Finally,according to the time-space-strength relations,a quantitative assessment of the influence of rock-mass damage on the dynamic roof instability was accomplished.

关键词：