Hard rock blasting energy distribution and fragmentation characteristics under high earth stress

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Journal of Vibration and Shock ›› 2018, Vol. 37 ›› Issue (15) : 143-149.

XIAO Siyou1,2,3,JIANG Yuanjun1,2,LIU Zhixiang3,SU Lijun1,2,4

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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.

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high earth stress / blasting energy / dynamic unloading / fracture / strain energy releasing / damage failure

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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[J]. Journal of Vibration and Shock, 2018, 37(15): 143-149

References

[1] YAN P, ZHAO Z, LU W B, et al. Mitigation of rock burst events by blasting techniques during deep-tunnel excavation[J]. Engineering Geology, 2015, 188: 126-136.
[2] 杨栋，李海波，夏祥，等. 高地应力条件下爆破开挖诱发围岩损伤破坏的特性研究[J]. 岩土力学，2014(4): 1110-1116.
YANG Dong, LI Hai-bo, XIA Xiang, et al. Study of blasting-induced dynamic damage of tunnel surrounding rocks under high in-situ stress[J]. Rock and Soil Mechanics, 2014(4): 1110-1116.
[3] 李夕兵，姚金蕊，杜坤. 高地应力硬岩矿山诱导致裂非爆连续开采初探-以开阳磷矿为例[J]. 岩石力学与工程学报，2013，32(6): 1101-1111.
LI Xi-bing，YAO Jin-rui，DU Kun. Prelimnary study for induced fracture and non-explosive continuous mining in high-geostrss hard rock mine-a case study for KaiYang phosphate mine[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(6): 1101-1111.
[4] 李夕兵，姚金蕊，宫凤强. 硬岩金属矿山深部开采中的动力学问题[J]. 中国有色金属学报，2011，21(10):2551-2563.
LI Xi-bing, YAO Jin-rui, GONG Feng-qiang. Dynamic problems
In deep exploitation of hard rock metal mines[J]. The Chinese Journal of Nonferrous Metals, 2011, 21(10): 2551-2563.
[5] YAN P, LU W B, CHEN M, et al. Contributions of In-Situ Stress Transient Redistribution to Blasting Excavation Damage Zone of Deep Tunnels[J]. Rock Mechanics and Rock Engineering, 2015, 48(2):715-726.
[6] Bastante F G, Alejano L, González-Cao J. Predicting the extent of blast-induced damage in rock masses[J]. International Journal of Rock Mechanics & Mining Sciences, 2012, 56(2): 44-53.
[7] Hamdi E, Romdhane N B, Cléac’H J M L. A tensile damage model for rocks: Application to blast induced damage assessment[J]. Computers & Geotechnics, 2011, 38(2): 133-141.
[8] TAO M, LI X B, WU C Q. 3D numerical model for dynamic loading-induced multiple fracture zones around underground cavity faces[J]. Computers & Geotechnics, 2013, 54(10): 33-45.
[9] 严鹏，卢文波，许红涛. 高地应力条件下隧洞开挖动态卸荷的破坏机理初探[J]. 爆炸与冲击， 2007，27（3）: 283-288.
YAN Peng, LU Wen-bo, XU Hong-tao. A primary study to damage mechanics of initial stress dynamic unloading when excavating under high geostress condition[J]. Explosion and Shock Waves, 2007, 27(3): 283-288.
[10] 严鹏，卢文波，陈明，等. 初始地应力场对钻爆开挖过程中围岩振动的影响研究[J]. 岩石力学与工程学报，2008，27(5): 1036-1045.
YAN Peng, LU Wen-bo, CHEN Ming, et al. Study on impaction of initial geostress field on vibration of surrounding rock during excavation with drilling and blasting method[J]. Chinese Journal of Rock Mechanics and Engineering, 2008, 27(5): 1036-1045.
[11] 易长平，卢文波，许红涛，等. 岩石开挖过程初始应力的动态卸荷效应研究[J]. 岩石力学与工程学报，2005，24(增1)：4 750–4 754.
YI Chang-ping, LU Wen-bo, XU Hong-tao, et al. Dynamic unloading effect study of initial stress field in excavation process of large-scale rock mass structure[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(Supp.1): 4750–4754.
[12] 卢文波, 金李, 陈明．节理岩石爆破开挖过程的动态卸载松动机理研究[J]．岩石力学与工程学报，2005，24(1)：4653-4 657．
LU Wen-bo, JIN Li, CHEN Ming. Study on the mechanism of the loosing of the jointed rock mass caused by the dynamic unloading of initial stress during rock blasting[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(1): 4653-4657.
[13] LI X B, CAO W Z, ZHOU Z L, et al. Influence of stress path on excavation unloading response[J]. Tunnelling and Underground Space Technology, (42)2014, 237-246.
[14] LI X B, CAO W Z, TAO M, et al. Influence of unloading disturbance on adjacent tunnels[J]. International Journal of Rock Mechanics & Mining Sciences, 2016, 84:10-24.
[15] 谢和平，彭瑞东，鞠杨等. 岩石破坏的能量分析初探[J]. 岩石力学与工程学报，2005，24(15): 2603-2608.
XIE He-ping, PENG Rui-dong, JU Yang. On energy analysis of rock failure[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(15): 2603-2608.
[16] 唐红梅，周云涛，廖云平. 地下工程施工爆破围岩损伤分区研究[J]. 振动与冲击，2015，34 (23):202-206.
TANG Hong-mei, ZHOU Yun-tao, LIAO Yun-ping. Damage Zone of surrounding rock of underground engineering under blasting[J]. Journal of vibration and shock, 2015, 34 (23):202-206.
[17] Kutter H K. Fairhurst. On the fracture process in blasting[J]. International Journal of Rock Mechanics and Mining Sciences, 1971, 8(2): 181-202.
[18] 吴亮，卢文波，宗琦. 岩石中柱状装药爆炸能量分布[J]. 岩土力学，2006，27（5）：735-739.
WU Liang，LU Wenbo，ZONG Qi. Distribution of explosive energy consumed by column charge in rock[J]. Rock and Solid Mechanics ，2006，27(5)：735-739.
[19] 戴俊. 岩石动力学特性与爆破理论[M].北京:冶金工业出版社，2002.
[20] J. Henrych, ABRAHAMSON G R. The dynamic of explosion and its use[J]. Journal of Applied Mechanics, 1979.
[21] 宗琦. 岩石爆破的扩腔作用及能量消耗[J]. 煤炭学报，1997，22(4): 392－396.
ZONG Qi. Function of cavity expansion and energy consumption in rock blasting[J]. Journal of China Coal Society, 1997, 22(4): 392-396.
[22] 穆朝民，齐娟. 爆炸荷载作用下煤体裂纹扩展机理模型实验研究[J]. 振动与冲击，2012，31(13):58-61.
MU Chao-min, QU Juan. Model investigation on cracks propagation in coal under blasting load[J]. Journal of vibration and shock, 2012, 31(13): 58-61.
[23] 李庆芬. 断裂力学及其工程运用[M]. 哈尔滨：哈尔滨工程大学出版社，1998.
LI Qin-fen. Fracture Mechanics and Engineering Application[M].Harbin:Harbin Engineering University press，1998.
[24] 许红涛，卢文波. 爆破破岩过程中的动态卸载效应探讨[J]. 岩土力学，2004， 24(6): 969-973.
XU Hong-tao, LU Wen-bo. Study on dynamic unloading effect during process of fragmentizing rock by blasting[J].Rock and Solid Mechanics，2004， 24(6): 969-973.
[25] 孙金山，金李，姜清辉,等. 地下洞室爆破开挖过程中地应力瞬态调整诱发节理围岩松动机制研究[J]. 振动与冲击，2011，30(12):28-34.
SUN Jin-shan, JIN Li, JIANG Qinhua, et al. Loosing of jointed rock mass induced by transient adjustment of in-situ stress[J]. Journal of vibration and shock, 2011, 30(12): 28-34.
[26] Carter J P ，Booker J R. Sudden Excavation of a Long Circular Tunnel in Elastic Ground[J]．International Journal of Rock M ining Science & Geomechanics Abstract．1990，27(2)：l29—132.
[27] Talbot, A. The accurate numerical inversion of Laplace transforms[J]. Journal of the Institute of Mathematics & Its Applications, 1979, 23(1), 97-120.
[28] CAO W Z, LI X B, TAO M, et al. Vibrations induced by high initial stress release during underground excavations[J]. Tunnelling & Underground Space Technology, 2016, 53: 78-95.
[29] 范勇，卢文波，严鹏,等. 地下洞室开挖过程围岩应变能调整力学机制[J]. 岩土力学，2013(12):3580-3586.
FAN Yong, LU Wen-bo, YAN Peng, CHEN Ming. Mechanism of strain energy adjustment of surrounding rock during excavation of underground caverns[J]. Rock and Soil Mechanics, 2013(12):3580-3586.
[30] LU W B, YANG J H, YAN P, et al. Dynamic response of rock mass induced by the transient release of in-situ stress[J]. International Journal of Rock Mechanics & Mining Sciences, 2012, 53(9): 129-141.
[31] 谢和平，鞠杨，黎立云. 基于能量耗散与释放原理的岩石强度与整体破坏准则[J]. 岩石力学与工程学报，2005，24(17): 3003－3010.
XIE He-ping, JU Yang, LI Li-yun. Criteria for strength and structural failure of rocks based on energy dissipation and energy release principles[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(17): 3003-3010.