Considerations of the discontinuous deformation analysis on wave propagation problems

Abstract

SUMMARYIn rock engineering, the damage criteria of the rock mass under dynamic loads are generally governed by the threshold values of wave amplitudes, such as the peak particle velocity and the peak particle acceleration. Therefore, the prediction of wave attenuation across fractured rock mass is important on assessing the stability and damage of rock mass under dynamic loads. This paper aims to investigate the applications of the discontinuous deformation analysis (DDA) for modeling wave propagation problems in rock mass. Parametric studies are carried out to obtain an insight into the influencing factors on the accuracy of wave propagations, in terms of the block size, the boundary condition and the incident wave frequency. The reflected and transmitted waves from the interface between two materials are also numerically simulated. To study the tensile failure induced by the reflected wave, the spalling phenomena are modeled under various loading frequencies. The numerical results show that the DDA is capable of modeling the wave propagation in jointed rock mass with a good accuracy.

Numerical and analytical investigation of compressional wave propagation in saturated soils

“…The discrete element method (e.g. Gu andZhao (2009), Wu (2010)) has also been employed to investigate the compressional wave propagation in rock materials associated with slope failures. However, these studies concentrate on the investigation of the fast waves without accounting for the HM behaviour of saturated porous materials.…”

Numerical Simulation of Crack Growth and Coalescence in Rock-Like Materials Containing Multiple Pre-existing Flaws

“…The DDA with discrete blocks bounded by artificial joints has also been used to model failures in intact rock (Gu and Zhao 2009;Ning et al 2010). Fracturing is realized by converting artificial joints into real joints once a failure criterion is met; however, the predicted crack trajectory is dependent on the advance block discretization configuration (Ning et al 2011).…”

Application of the discontinuous deformation analysis method to stress wave propagation through a one-dimensional rock mass

“…Using the principle of minimum potential energy, the contributions of the viscous boundary to the DDA equations are obtained: ; n x and n y are the direction cosines of the block boundary; {ΔḊi} denotes the velocity vector of the block. Relative to previous studies, 31 the viscous boundary implemented by this paper is more efficient and has a high absorption precision. 25 Based on the viscous boundary, a force input method is used for inputting the incident wave.…”