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| DYNAMIC RESPONSE OF DEFECTED ROCK UNDER BLASTING LOAD |
| ZHU Zheming，LI Yuanxin，ZHOU Zhirong，RAN Xu，JIN Xinxing |
| (Department of Engineering Mechanics，Sichuan University，Chengdu，Sichuan 610065，China) |
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Abstract Based on the experiment results，a surface blasting model of rock with pre-existing defects，including voids，pores and small open joints under blasting loads is established. The defects are randomly distributed，and are empty or saturated with water. A shock equation of state (EOS)，obtained from the existing test results，is employed for the granite near the explosive charge；and for the granite far from the charge，a linear EOS is applied. A modified principal stress failure criterion is applied to determining the granite statuses. The granite dynamic strengths，which increase with the strain rate，are calculated from the existing test results. The simulation results show that：under blasting，as rock contains water，its dynamic strength decreases；the larger the defect density is，the smaller the damage range is. A blasting near a tunnel induces spalling cracks near tunnel free surface easily；and combining with the radial cracks caused during tunnel blasting excavation，the surrounding rock near the tunnel free surface would be cut into a group of blocks which may fall down and may result in rock burst.
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Received: 14 February 2011
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| [1] STEIF P S. Crack extension under compressive loading[J]. Engineering Fracture Mechanics，1984，20(3)：463–473.
[2] ZHU Z M，WANG L，MOHANTY B，et al. Stress intensity factor for a cracked specimen under compression[J]. Engineering Fracture Mechanics，2006，73(4)：482–489.
[3] ZHU Z M. New biaxial failure criterion for brittle materials in compression[J]. Journal of Engineering Mechanics，ASCE，1999，125(11)：1 251–1 258.
[4] ZHU Z M. An alternative form of propagation criterion for two collinear cracks under compression[J]. Mathematics and Mechanics of Solids，2009，14(8)：727–746.
[5] ZHU Z M，XIE H P，JI S. The mixed boundary problems for a mixed mode crack in a finite plate[J]. Engineering Fracture Mechanics，1997，56(5)：647–655.
[6] LI Y X，ZHU Z M，LI B X，et al. Study on the transmission and reflection of stress waves across joints[J]. International Journal of Rock Mechanics and Mining Sciences，2011，48(3)：364–371.
[7] ZHU Z M，MOHANTY B，XIE H P. Numerical investigation of blasting-induced crack initiation and propagation in rocks[J]. International Journal of Rock Mechanics and Mining Sciences，2007，44(3)：412–424.
[8] ZHU Z M，XIE H P，MOHANTY B. Numerical investigation of blasting-induced damage in cylindrical rocks[J]. International Journal of Rock Mechanics and Mining Sciences，2008，45(2)：111–121.
[9] ZHU Z M. Numerical prediction of crater blasting and bench blasting[J]. International Journal of Rock Mechanics and Mining Sciences，2009，46(6)：1088–1 096.
[10] GRADY D E，KIPP M E. Continuum modeling of explosive fracture in oil shale[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1980，17(3)：147–157.
[11] NILSON R H，PROFFER W J，DUFF R E. Modeling of gas-driven fractures induced by propellant combustion within an explosion cavity[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1985，22(1)：3–19.
[12] MA J W，AN X M. Numerical simulation of blasting-induced rock fractures[J]. International Journal of Rock Mechanics and Mining Sciences，2008，45(6)：966–975.
[13] CHEN S G，ZHAO J. A study of UEDC modeling for blasting wave propagation in joint rock mass[J]. International Journal of Rock Mechanics and Mining Sciences，1998，35(1)：93–99.
[14] WANG Z L，LI Y C，WANG J G. Numerical analysis of blasting- induced wave propagation and spalling damage in a rock plate[J]. International Journal of Rock Mechanics and Mining Sciences，2008，45(4)：600–608.
[15] LU Y，XU K. Modelling of dynamic behaviour of concrete materials under blast loading[J]. International Journal of Solids and Structures，2004，41(1)：131–143.
[16] RIEDEL W. Beton unter dynamischen lasten：meso- und makromechanische[Ph. D. Thesis][D]. Freiburg，Germany：Universitat der Bundeswehr，Munchen，2000.
[17] DAI F，HUANG S，XIA K，et al. Some fundamental issues in dynamic compression and tension tests of rocks using split hopkinson pressure bar[J]. Rock Mechanics and Rock Engineering，2010，43(6)：657–666.
[18] WILKINS M L. Use of artificial viscosity in multidimensional fluid dynamic calculations[J]. Journal of Computational Physics，1980，36(3)：281–303.
[19] Century Dynamics Inc.. Autodyn theory manual[R]. Concord，CA，USA：Century Dynamics Inc.，2003.
[20] MARSH S P. LASL shock hugoniot data[M]. Berkeley：University of California Press，1980：390–400.
[21] BAKKEN L H. ANDERSON P D. The complete equation of state handbook[M]. New Mexico：Sandia Corporation SCL–TM–67–118，1967：10–50.
[22] LEE E，FINGER M，COLLINS W. JWL equation of state coefficients for high explosives[R]. Lawrence：Technical Report UCID–16189，Lawrence Livermore National Laboratory，1973.
[23] ZHOU Z T，ZHU Z M，JIN X X，et al. Numerical prediction of rock fracturing during the process of excavation[J]. International Journal of Geotechnical Earthquake Engineering，2010，1(2)：12–23.
[24] ZHOU Z T，ZHU Z M，JIN X X，et al. Numerical Prediction of Rock Fracturing during Blasting Excavation[C]// International Conference on Mechanic Automation and Control Engineering. Wuhan：[s.n.]，2010：756–759. |
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2011, Vol. 30 
