Loading Rate Dependency of Dynamic Responses of Rock Joints at Low Loading Rate

List of Symbols ej Measured strain wave at the position of the gauge j (j = a, b) e; e Positive and negative strain waves, respectively epj ; e n j Positive and negative strain waves at the position of the gauge j (j = a, b), respectively ei; er; et Incident, reflected and transmitted strain waves, respectively e ; epþ Positive strain waves at the front and back sides of rock joints, respectively e ; enþ Negative strain waves at the front and back sides of rock joints, respectively e ; eþ Strains at the front and back sides of rock joints, respectively _ ef Strain rate of filled joints Den Normalized closure of non-filled contact joints Def Normalized closure of filled joints Dt Time interval for positive or negative strain wave propagation between the points a and b r ; rþ Stresses on the front and back sides of rock joints, respectively rn Stress of non-filled contact joints rf Stress of filled joints c Longitudinal wave propagation velocity E Young’s modulus of the rock bar l Length of the rock bar ls Thickness of the filled joint T Transmission coefficient t j Time interval for positive strain wave propagation between the points O and j (j = a, b) t j Time interval for negative strain wave propagation between the points Y and j (j = a, b) v ; vþ Particle velocities at the front and back sides of rock joints, respectively xj Distance between the points O and j (j = a, b)