Parameter Identification of Elastic Modulus of Rock Based on Blasting Waves in Tunnel Excavation

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The objective of this research is to present an identification method for elastic moduli of ground rock, through the first-order adjoint equation method using the measurements of the blasting vibration in tunnel excavation. Parameter identification is a minimization problem of the square sum of discrepancy between the computed and observed velocities. For the identification of these parameters, the magnitudes of the blasting force should be identified beforehand. In this study, propagation of an elastic wave is assumed because the amplitude of such a wave is infinitesimal. After the identification of the blasting force, the elastic moduli of three layers are identified simultaneously. We assume that the damping of vibration is linear. By applying the identification technique at the Ohyorogi tunnel site, we verify that the method is useful for tunnel excavation. Using measured data from actual tunnel excavation sites, the numerical identification method presented in this paper is shown to be useful for practical tunnel excavation.

Y. Motoyama and M. Kawahara, "Parameter Identification of Elastic Modulus of Rock Based on Blasting Waves in Tunnel Excavation", Advanced Materials Research, Vols. 403-408, pp. 75-79, 2012

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