Probabilistic estimation of fully coupled blasting pressure transmitted to rock mass II - Estimation of rise time -

Bong-Ki* Park; In-Mo Lee; Sang-Gyun Kim; Sang-Don Lee; Kook-Hwan Cho

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2004 Vol.6, Issue 1 Preview Page Next Page

Probabilistic estimation of fully coupled blasting pressure transmitted to rock mass II - Estimation of rise time - 암반에 전달된 밀장전 발파압력의 확률론적 예측 II - 최대압력 도달시간 예측을 중심으로 -

31 March 2004. pp. 25-40

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Abstract

The supersonic shock wave generated by fully coupled explosion will change into subsonic shock wave, plastic wave, and elastic wave consecutively as the wave propagates through rock mass. While the estimation of the blast-induced peak pressure was the main aim of the companion paper, this paper will concentrate on the estimation of the rise time of blast-induced pressure. The rise time can be expressed as a function of explosive density, isentropic exponent, detonation velocity, exponential coefficient of the peak pressure attenuation, dynamic yield stress, plastic wave velocity, elastic wave velocity, rock density, Hugoniot parameters, etc. Parametric analysis was performed to pinpoint the most influential parameter that affects the rise time and it was found that rock properties are more sensitive than explosive properties. The probabilistic distribution of the rise time is evaluated by the Rosenblueth's point estimate method from the probabilistic distributions of explosive properties and rock properties. Numerical analysis was performed to figure out the effect of rock properties and explosive properties on the uncertainty of blast-induced vibration. Uncertainty analysis showed that uncertainty of rock properties constitutes the main portion of blast-induced vibration uncertainty rather than that of explosive properties. Numerical analysis also showed that the loading rate, which is the ratio of the peak blasting pressure to the rise time, is the main influential factor on blast-induced vibration. The loading rate is again more influenced by rock properties than by explosive properties.

Keywords

Peak blasting pressure

rise time

blast-induced vibration

loading rate

밀장전한 암반발파공에서 화약폭발로 전파되는 초음속 충격파는 암반중에 전파되면서 차차로 저음속 충격파, 소성파, 탄성파로 변화된다. 이 연구는 발파압력파의 최대압력 도달시간 산정에 중점을 두었고 연계된 논문 I (the companion paper)에서는 최대 발파압력 산정에 중점을 두었다. 이 연구에서 최대압력 도달시간을 화약밀도, 단열지수, 폭굉파속도, 감쇠지수, 동적항복강도, 소성파속도, 암반밀도, 탄성파속도, Hugoniot 상수의 함수식으로 유도하였다. 최대압력 도달시간에 대한 매개변수분석 결과 암반특성치가 화약특성치보다 더 크게 영향을 미쳤다. 최대압력 도달시간의 확률분포는 화약과 암반 특성치의 확률분포로부터 Rosenblueth 확률모델로 조합하여 산출되었다. 화약과 암반특성의 불확정성이 발파진동의 불확정성에 미치는 영향을 수치해석으로 분석하였다. 불확정성 분석결과 화약특성보다 암반특성의 불확정성이 발파진동에 더 크게 영향을 미쳤다. 수치해석 분석결과 최대 발파압력과 최대압력 도달시간의 비인 하중재하율이 발파진동에 큰 영향을 미쳤다. 또한 화약특성보다 암반특성이 하중재하율에 더 크게 영향을 미쳤다.

키워드

최대발파압력

최대압력 도달시간

발파진동

하중재하율

References

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Information

Publisher :Korean Tunneling and Underground Space Association
Publisher(Ko) :한국터널지하공간학회
Journal Title :Journal of Korean Tunnelling and Underground Space Association
Journal Title(Ko) :한국터널지하공간학회 논문집
Volume : 6
No :1
Pages :25-40

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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