Normally incident wave propagation across a joint set with the virtual wave source method

This paper presents an analytical study on normally incident wave propagation across a joint set. Combined with the displacement discontinuity method (DDM), the virtual wave source method (VWSM) is adopted to take account of multiple wave reflections among joints. After theoretical formulation, a comparison between results from VWSM and those from the method of characteristics (MC) is carried out. These results agree well with each other, and the applicability of VWSM into wave propagation study is verified. Subsequently, an interesting phenomenon, i.e., the magnitude of transmission coefficient increases with joint number on some circumstances, is pointed out and studied. By analyzing differently arriving transmitted waves and their superposition, such phenomenon is explained. ► A modified virtual wave source method is introduced and validated. ► The modified method has several advantages. ► Wave propagation through jointed rock masses is studied. ► An “abnormal” phenomenon is pointed out and explained.