ENERGY ANALYSIS OF STRESS WAVE PROPAGATION ACROSS PARALLEL NONLINEAR JOINTS
LIU Tingting,LI Jianchun,LI Haibo,CHAI Shaobo
(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
Abstract:Studying stress wave propagation across fractured rock mass is crucial to estimate the safety of an underground construction. This paper is concerned with an obliquely incident longitudinal wave(P-wave) propagation across a set of parallel joints. The Barton-Bandis model(B-B model) and the linear elastic model are adopted to describe the normal and shear properties of the joints,respectively. Based on the time-domain recursive method,the stress wave propagation equation is firstly established. Secondly,the analysis of energy transmission is carried out;and the transmitted and reflected energies for P-wave propagation across the joints are calculated. Finally,parametric study is conducted for the effects of the joint initial stiffness,the joints spacing,the amplitude,the frequency and angle of incident waves on the energy transmission. The analytical results show that the stress wave energy transmission is related not only to the mechanical properties of the joints but also to the geometrical distribution of the joints,i.e. the joint spacing and direction. The result also shows the variation of the stress wave energy transmission with the frequency and amplitude of an incident wave.
LI J C,MA G W,ZHAO J. An equivalent viscoelastic model for rock mass with parallel joints[J]. Journal of Geophysical Research:Solid Earth,2010,115(B03305).
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