UBC Theses and Dissertations
Debris torrent mechanisms Smyth, Kenneth Jeffrey
The phenomenon of the debris torrent is explored by examining the mechanisms of initiation, particularly those of rainfall and deforestation. The types of precipitation likely to contribute to instability are identified and data collection is reviewed. Debris torrents have characteristics unlike that of ordinary stream flow, and are capable of transporting massive quantities and sizes of material. Models to explain this transport capability are compared and contrasted. A theoretical analysis of the flow regime is carried out which is argued to be consistent with the observed turbulent nature of a debris torrent. This analysis is extended to the calculation of superelevation in bends and shows that current attempts to estimate velocities from super-elevation data may be very conservative. Further application of the turbulent stress analysis is used to estimate the angle of spread of the debris torrent in the deposition zone, and this analysis may be useful in zoning the downstream area to safeguard construction.