Pseudo‐plane strain analysis of wave propagation problems arising from detonations of explosives in cylindrical boreholes

Abstract

AbstractWave propagation problems, such as blasting for excavation of a new tunnel oriented perpendicular to an existing tunnel, are truly three dimensional in nature. Dynamic finite element analysis with three‐dimensional elements is, however, very expensive. The cheaper and simpler alternative would be to model the problem approximately in two dimensions. This paper shows that dynamic finite element analysis of such problems using conventional two‐dimensional plane strain elements produces responses which are erroneously excessive. This is accredited to the inability to the inability of the two‐dimensional elements to correctly model the rapid attenuation of the amplitudes of the outward propagating waves. To overcome this problem, a pseudo‐plane strain concept is introduced and has been found to be a viable alternative. Numerical results are presented to demonstrate the application of the concept.