68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

NON-DESTRUCTIVE INSPECTION OF THE SURFACE OF UNDERGROUND STRUCTURES BASED ON THE PROPAGATION OF SURFACE WAVE

Session: Insitu Testing and Instrumentation II / Essais in situ et instrumentation II

Simon-Pierre Tremblay, Université de Sherbrooke - Hydro-Québec (Canada)
Mourad Karray, Département de génie civil (Canada)
Mohamed Chekired, Hydro-Québec (Canada)
Carole Bessette, Hydro-Québec (Canada)
Livius Jinga, Hydro-Québec (Canada)

This article shows how the propagation of surface waves is affected by the presence and the state of degradation of an underground concrete structure. In previous work, the behavior of elastic waves propagating in a soil profile containing an underground concrete structure was modelled using 2-dimensional numerical models. One of the drawbacks of using 2D models to represent 3D structures is that 2D models neglect the effect that out-of-plane discontinuities may have on the propagation of elastic waves. A 2D profile is therefore not fully representative of an underground profile containing a small concrete structure compared to the size of the soil deposit surrounding it. This paper uses a 3D finite difference method implemented in FLAC3D to show how the presence of a manhole and of a discontinuity at the surface of an underground concrete structure affects the propagation of surface waves.