Evaluation of Blast influence by Artificial Joint in Concrete Block

콘크리트 블록에서 인공절리에 따른 발파영향 평가

  • Received : 2018.09.03
  • Accepted : 2018.09.17
  • Published : 2018.09.30

Abstract

This study was conducted to evaluate the influences of the angle of artificial joints, the distance between the artificial joints and the blast hole, and the number of artificial joints on the pressure wave propagation, crack propagation, and blast wave velocity. The evaluation was conducted numerically by use of the Euler-Lagrange solver supported by the AUTODYN, which is a dynamic FEM program. As a result, it was found that the blast wave velocity was decreased most rapidly as either the distance between the artificial joint and the blast hole was decreased or the angle of the artificial joint was increased. In contrast to the case of no artificial joint, the amount of attenuation of the blast wave velocity was considerably large when an artificial joint was present. However, the effect of the number of artificial joint on the attenuation of the blast wave velocity was negligible under the given condition.

본 연구는 인공절리의 경사, 인공절리와 발파공 간의 거리, 그리고 인공절리의 수가 압력파동의 전파, 균열의 전파, 그리고 발파파동의 속도에 미치는 영향을 평가할 목적으로 수행되었다. 이 평가작업은 동적 FEM 프로그램인 AUTODYN 상에서 지원되는 Euler-Lagrange solver를 사용하여 수행되었다. 주요 결과로서 발파파속은 인공절리와 발파공 간의 거리가 가깝거나 인공절리의 경사가 증가할수록 더 빠르게 감소하는 것으로 나타났다. 인공절리가 없는 경우에 비해 절리가 하나라도 존재하는 경우에는 발파파속의 감쇠가 상당히 크게 발생하였다. 하지만 인공절리의 수가 발파파속의 감쇠에 미치는 영향은 주어진 조건 하에서는 미미한 수준이었다.

Keywords

References

  1. Berta, G., 1994, Blasting-induced vibration in tunnelling, Tunnelling and Underground Space Technology, Vol. 9, No. 2, pp. 175-187. https://doi.org/10.1016/0886-7798(94)90029-9
  2. Hermann, W., 1969, Constitutive Equation for the Dynamic Compaction of Ductile Porous Materials, Journal of Applied Physics, Vol. 40, No. 6, pp. 2490-2499. https://doi.org/10.1063/1.1658021
  3. Jung, H. S., K. S. Jung, H. N. Mun, B. S. Chun and D. H. Park, 2011, A study on the Vibration Propagation Characteristics of Controlled Blasting Methods and Explosives in Tunnelling, Journal of Korean Geo- Environmental Society, Vol. 12, No. 2, pp. 5-14.
  4. Kim, J. G., 2012, Reduction of blasting-induced vibration in tunnelling using avrasive water jet notch and disc cutting, Ph.D. Dissertation, Seoul National University, Korea.
  5. Lee, H. H., S. K. Ahn, K. C. Lee, C. S. Bang and M. Sagong, 2015, Study on a Wire Saw Rock Cutting Model for Tunnel Excavation and Cutting Performance Improvement, Transactions Korean Society of Mechanical Engineering A, Vol. 39, No. 10, pp. 1069-1077. https://doi.org/10.3795/KSME-A.2015.39.10.1069
  6. Oh, T. M., G. C. Cho, K. I. Song and I. T. Ji 2012, A new rock excavation method using an abrasive waterjet to minimized excavation damaged zone, Proceedings of World Tunnel Congress 2012, Bangkok, Thailand, pp. 340-341.
  7. Park, D. H., B. K. Jeon and S. W. Jeon, 2009, A numerical study on the screening of blast-induced waves for reducing ground vibration, Rock Mechanics and Rock Engineering, Vol. 42, pp. 449-473. https://doi.org/10.1007/s00603-008-0016-y
  8. Riedel, W., K. Thomas, S. Hiermaier and E. Schmolinske, 1999, Penetration of Reinforced Concrete by BETA-B-500 Numerical Analysis using a New Macroscopic Concrete Model for Hydrocodes, 9th International Symposium on the Interaction of the Effects of Munitions with Structures, Berlin-Strausberg, Germany, pp. 315-322.
  9. Sanchidrian, J. A., R. Castedo, L. M. Lopez, P. Segarra and A. P. Santos, 2015, Determination of the JWL constants for ANFO and emulsion explosives from cylinder test data, Central European journal of energetic materials, Vol. 12, No. 2, pp. 177-194.