Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
권호 표지
DOI QR코드

DOI QR Code

Propagation characteristics of blast-induced vibration to fractured zone

파쇄영역에 따른 발파진동 전파특성

  • Ahn, Jae-Kwang (Geotechnical Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Park, Duhee (Dept. of Civil and Environmental Engineering, Hanyang University) ;
  • Park, Ki-Chun (Dept. of Civil and Environmental Engineering, Hanyang University, BMSENC Co. Ltd.) ;
  • Yoon, Ji Nam (Dept. of Civil and Environmental Engineering, Hanyang University, Infra Division Sr. POSCO E&C)
  • 안재광 (한국건설기술연구원 지반연구소) ;
  • 박두희 (한양대학교 건설환경공학과) ;
  • 박기천 (한양대학교 건설환경공학과, (주)비엠에스이앤씨) ;
  • 윤지남 (한양대학교 건설환경공학과, 포스코건설 인프라사업본부)
  • Received : 2017.10.11
  • Accepted : 2017.11.07
  • Published : 2017.11.30
Download PDF
⟨ Previous Next ⟩

Abstract

In evaluation of blast-induced vibration, peak particle velocity (PPV) is generally calculated by using attenuation relation curve. Calculated velocity is compared with the value in legal requirements or the standards to determine the stability. Attenuation relation curve varies depending on frequency of test blasting, geological structure of the site and blasting condition, so it is difficult to predict accurately using such an equation. Since PPV is response value from the ground, direct evaluation of the structure is impractical. Because of such a limit, engineers tend to use the commercial numerical analysis program in evaluating the stability of the structure more accurately. However, when simulate the explosion process using existing numerical analysis program, it's never easy to accurately simulate the complex conditions (fracture, crushing, cracks and plastic deformation) around blasting hole. For simulating such a process, the range for modelling will be limited due to the maximum node count and it requires extended calculation time as well. Thus, this study is intended to simulate the elastic energy after fractured zone only, instead of simulating the complex conditions of the rock that results from the blast, and the analysis of response characteristics of the velocity depending on shape and size of the fractured zone was conducted. As a result, difference in velocity and attenuation character were calculated depending on fractured zone around the blast source appeared. Propagation of vibration tended to spread spherically as it is distanced farther from the blast source.

발파진동 안정성 평가는 일반적으로 발파 진동추정식을 통해 최대진동속도(PPV)를 산정하고 추정된 속도 값과 법규 혹은 기준에 제시된 허용 기준 값을 비교하여 안정성 여부를 판단한다. 현장 고유의 발파 진동추정식은 시험 발파의 횟수, 대상지반의 지질학적 구조와 발파 조건에 따라 달라지기 때문에 이 식을 통해 정확한 응답 값을 예측하는 것은 한계가 있다. 또한 최대진동속도는 지반에 예상되는 응답 값으로 구조물에 대한 직접적인 평가는 불가능하다. 이와 같은 한계점으로 인해 발파 진동에 대한 구조물의 정밀한 안정성을 평가할 경우 엔지니어들은 상용화된 수치해석 프로그램을 이용한다. 하지만 폭발로 인해 발생하는 발파공 주변 암반의 복합적인 상태변화(파쇄, 분쇄, 균열, 소성변형)를 기존 수치해석 프로그램으로 정확히 모델링 하기가 쉽지 않다. 만약 이러한 일련의 과정을 모사할 경우 절점 수의 제한으로 인해 모델링이 가능한 범위가 한정적이고 긴 연산시간이 소요된다. 따라서, 본 연구에서는 폭발로 발생하는 암반의 복합적 상태변화 과정을 모사하지 않고 파쇄영역 이후 탄성에너지 전파만을 모사하는 해석 방법에 대한 연구를 수행하였으며, 이때 파쇄영역의 형상 및 크기에 따른 속도의 응답특성을 분석하였다. 그 결과 폭원 주변에서는 설정되는 파쇄영역에 따라 계산된 속도의 크기 및 감쇠에 차이를 보였다. 전파되는 진동은 폭원으로부터 멀어질수록 구형으로 확산되는 것으로 나타났다.

Keywords

References

  1. Ahn, J.K., Park, D.H. (2017), "Prediction of near-field wave attenuation due to a spherical blast source", Rock Mechanics and Rock Engineering, Vol. 50, No.11, pp. 3085-3099. https://doi.org/10.1007/s00603-017-1274-3
  2. Ahn, J.K., Park, D.H., Shin, Y.W., Park, I.J. (2014), "Generation of blast load time series under tunnelling", Journal of Korean Tunnelling and Underground Space Association, Vol. 16, No. 1, pp. 51-61. https://doi.org/10.9711/KTAJ.2014.16.1.051
  3. AUTODYN, A. (2009), "Interactive non-linear dynamic analysis software, version 12, user's manual", SAS IP Inc.
  4. Blair, D.P. (2014), "Blast vibration dependence on charge length, velocity of detonation and layered media", International Journal of Rock Mechanics and Mining Sciences, Vol. 65, pp. 29-39. https://doi.org/10.1016/j.ijrmms.2013.11.007
  5. Blair, D.P. (2015), "Wall control blasting. Rock fragmentation by blasting", Australia in Proceedings 11th International Symposium on Rock Fragementation by Blasting, pp. 13-26
  6. Chen, S.G., Cai, J.G., Zhao, J., Zhou, Y.X. (2000), "Discrete element modelling of an underground explosion in a jointed rock mass", Geotechnical & Geological Engineering, Vol. 18, No. 2, pp. 59-78. https://doi.org/10.1023/A:1008953221657
  7. Choi, S.O., Park, E.S., Sunwoo, C., Chung, S.K. (2004), "A study on the blasting dynamic analysis using the measurement vibration waveform", Journal of Korean Society for Rock Mechanics, Vol. 14, No. 2, pp. 108-120.
  8. Company, A.P. (1987), Explosives and rock blasting, Dallas.
  9. Deng, X.F., Zhu, J.B., Chen, S.G., Zhao, Z.Y., Zhou, Y.X., Zhao, J. (2014), "Numerical study on tunnel damage subject to blast-induced shock wave in jointed rock masses", Tunnelling and Underground Space Technology, Vol. 43, pp. 88-100. https://doi.org/10.1016/j.tust.2014.04.004
  10. Duvall, W.I. (1953), "Strain-wave shapes in rock near explosions", Geophysics, Vol. 18, No. 2, pp. 310-323. https://doi.org/10.1190/1.1437875
  11. Haibo, L., Xiang, X., Jianchun, L., Jian, Z., Bo, L., Yaqun, L. (2011), "Rock damage control in bedrock blasting excavation for a nuclear power plant", International Journal of Rock Mechanics and Mining Sciences, Vol. 48, No. 2, pp. 210-218. https://doi.org/10.1016/j.ijrmms.2010.11.016
  12. Hao, H., Wu, Y., Ma, G., Zhou, Y. (2001), "Characteristics of surface ground motions induced by blasts in jointed rock mass", Soil Dynamics and Earthquake Engineering, Vol. 21, No. 2, pp. 85-98. https://doi.org/10.1016/S0267-7261(00)00104-4
  13. Itasca Consulting Group, I. (2011), Fast Lagrange Analysis of Continua, Version 7.0.
  14. Jeon, S.S., Kim, D.S., Jang, Y.W. (2007), "Stability assessment of concrete lining and rock bolt of the adjacent tunnel by blast-induced vibration", Journal of Korean Geotechnical Society, Vol. 23, No. 10, pp. 33-45.
  15. Jiang, J., Baird, G., Blair, D. (1998), "Polarization and amplitude attributes of reflected plane and spherical waves", Geophysical Journal International, Vol. 132, No. 3, pp. 577-583. https://doi.org/10.1046/j.1365-246X.1998.00479.x
  16. Jiang, J., Blair, D.P., Baird, G.R. (1995), "Dynamic response of an elastic and viscoelastic full-space to a spherical source", International Journal for Numerical and Analytical Methods in Geomechanics, Vol. 19, No. 3, pp. 181-193. https://doi.org/10.1002/nag.1610190303
  17. Konya, C.J., Walter, E.J. (1991), Rock blasting and control overbreak, National Highway Institute, pp. 5.
  18. Lu, W., Yang, J., Chen, M., Zhou, C. (2011), "An equivalent method for blasting vibration simulation", Simulation Modelling Practice and Theory, Vol. 19, No. 9, pp. 2050-2062. https://doi.org/10.1016/j.simpat.2011.05.012
  19. Lysmer, J., Kuhlemeyer, R. (1969), "Finite dynamic model for infinite media", Journal of Engineering Mechanics Division. ASCE, Vol. 95, pp. 859-878.
  20. Park, D.H., Shin, J.H., Yun, S.U. (2010), "Seismic analysis of tunnel in transverse direction part II: Evaluation of seismic tunnel response via dynamic analysis", Journal of Korean Geotechnical Society, Vol. 26, No. 6, pp. 71-85.
  21. Richart, F.E., Hall, J.R., Woods, R.D. (1970), "Vibrations of soils and foundations", pp. 414.
  22. Sainoki, A., Mitri, H.S. (2016), "Dynamic modelling of fault slip induced by stress waves due to stope production blasts", Rock Mechanics and Rock Engineering, Vol. 49, No. 1, pp. 165-181. https://doi.org/10.1007/s00603-015-0721-2
  23. Siskind, D.E. (2000), "Vibration from blasting, international society of explosives engineers", Cleveland, OH, USA.
  24. Starfield, A.M., Pugliese, J.M. (1968), "Compression waves generated in rock by cylindrical explosive charges: a comparison between a computer model and field measurements", International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts: Elsevier, Vol. 5, No. 1, pp. 65-77. https://doi.org/10.1016/0148-9062(68)90023-5
  25. Wu, C., Lu, Y., Hao, H. (2004), "Numerical prediction of blast-induced stress wave from large-scale underground explosion", International Journal for Numerical and Analytical Methods in Geomechanics, Vol. 28, No. 1, pp. 93-109. https://doi.org/10.1002/nag.328