Dual-Mesh Three Characteristic Lines Method for Stress Wave Propagation Through a Microdefected Rock Mass with a Thin-Layer Filled Macrojoint.

A dual-mesh three characteristic lines method was proposed for stress wave propagation through a microdefected rock mass containing a thin-layer filled macrojoint. The dual-mesh three characteristic lines are composed of five basic elements that are used to calculate stress wave propagation at the boundary and the interior of the microdefected rock mass and the left side, interior and right side of the filled macrojoint. The results of the present study were compared with that of available analytical results that do not consider microdefects and do not consider microdefects and macrojoint thickness. The results show that the proposed method can be used to efficiently investigate the effect of microdefects and filled macrojoints on wave propagation. The results also show that the viscosity coefficient in the equivalent viscoelastic model of the microdefected rock mass, the viscosity coefficient in the equivalent viscoelastic model of the filled macrojoint and the thickness of the filled macrojoint have significant effects on stress wave attenuation. The transmission coefficient initially decreases and then increases as the viscosity coefficient in the equivalent viscoelastic model of the microdefected rock mass increases. The transmission coefficient increases and then tends to flatten as the viscosity coefficient in the equivalent viscoelastic model of the filled macrojoint increases. The transmission coefficient decreases as the thickness of the filled macrojoint increases. [ABSTRACT FROM AUTHOR]