1.Key Lab of Mountain Hazards and Earth Surface Processes,Chinese Academy of Sciences,Chengdu 610064,China;
2.University of Chinese Academy of Sciences,Beijing 100049,China;
3.School of Resources and Safety Engineering,Central South University,Changsha 410083,China;
4.CAS Center for Excellence in Tibetan Plateau Earth Sciences,Beijing 100101,China
Abstract:In order to study influences of dynamic unloading effect and blasting load under high earth stress on rock breaking effect and damage zone, rock stress distribution and fragmentation characteristics of crack zone and elastic one under blasting load and dynamic unloading wave were theoretically analyzed. The rock fragment size d and rock damage range Rd were calculated based on the fracture mechanics and the damage failure criterion for rock being able to release strain energy. The calculation results showed that when the initial earth stress reaches larger than 50MPa and the blast hole radius is 42mm, the released strain energy in 2# rock under the dynamic unloading can reach more than 16% of rock breaking energy in crack zone; after high earth stress is unloaded, the blast hole wall produces a radial tensile stress, it is 2MPa at the edge of fracture zone and the maximum tensile displacement is 0.24mm; in elastic zone, the strain energy releases along the radial direction under the action of radial tensile stress caused by dynamic unloading, a new damage zone is formed in elastic zone and its thickness is 0.03m; with increase in blast hole radius and crack zone one, the released energy under the dynamic unloading and the thickness of the damage zone in elastic zone are also enlarged.
肖思友1,3,4,姜元俊1,3,刘志祥4,苏立君1,2,3. 高地应力下硬岩爆破破岩特性及能量分布研究[J]. 振动与冲击, 2018, 37(15): 143-149.
XIAO Siyou1,2,3,JIANG Yuanjun1,2,LIU Zhixiang3,SU Lijun1,2,4. Hard rock blasting energy distribution and fragmentation characteristics under high earth stress. JOURNAL OF VIBRATION AND SHOCK, 2018, 37(15): 143-149.
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