터널 發破 掘鑿에서 發破壓力과 岩盤 損傷의 確率論적 接近
Probabilistic Assessment of Blast-induced Rock Pressure And Damage in Tunneling
화약 발파압력 암반손상;
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Probabilistic assessment of blast-induced rock pressure and damage model were studied to evaluate the damage of remaining rock surrounding an excavation line in tunneling. Equations for estimating the peak blasting pressure and rise time which are initiated under fully-coupled charge and decoupled-charge conditions were derived respectively as a function of explosive and rock properties. The blasting pressure under fully-coupled charge condition was derived from shock wave theory; that under decoupled charge condition was derived from ideal gas state equation. Sensitivity and uncertainty analysis were performed to identify the most influential parameters affecting on the peak blasting pressure and on the rise time. Probabilistic distributions of detonation wave velocity and density were obtained from results of explosion tests on Emulsion and Kinex explosives. The rise time under fully-coupled charge condition was evaluated from the analysis of stress wave-shape by transforming propagation distance into time domain. Meanwhile, that under decoupled charge condition was evaluated from the analysis of the sequential initiation of explosive and the propagation of gas pressure wave. The blast-induced waves were functions of peak blasting pressure, rise time and wave-shape function. The sensitivity and uncertainty analysis were also performed to identify the most influential parameters affecting on the blast-induced waves. The probabilistic distribution of the blast-induced wave was evaluated from the probabilistic distributions of explosive and rock properties by utilizing the Rosenblueth's point estimation method. The user-defined subroutine programs of isotropic and anisotropic rock damage model were developed in order to estimate the rock damage surrounding the excavation line induced by blasting work in tunneling. Sensitivity analysis was also performed to identify the most influential parameters affecting on the blast-induced isotropic and anisotropic rock damage. The damage of remaining rock surrounding the tunnel excavation line induced by blasting in contour holes as well as stopping holes was assessed considering the effect of blasting pressure magnitude, the effect of adapting either line drilling or sequential blasting, the effect of transmission ratio of the pressure in the hole to that transformed into surrounding rock after rock breakage.