A set of laboratory experiments on subaqueous debris flows is reported where total stress as well as pore pressure transducers were mounted in the bed. Sediment texture ranging from clayey (viscoplastic) to sandy (granular) were used in the experiments, in order to investigate changes in pressure evolution. The pressure readings confirm earlier studies suggesting that the front of the subaqueous clayey debris flow is hydroplaning on a thin layer of water, which causes low bed friction. Fronts of sandy debris flows show a fluidized head where bed friction is minimal.
Bibliographical noteFunding Information:
This research was carried out with financial support from the Research Council of Norway, Submarine Mass Wasting—Rheology, Flow Behaviour and Deposition Geometry (133975/431), the EU-project COSTA-contract no. EVK3-CT-1999-00006, the US Office of Naval Research and the International Centre for Geohazards, Norway. This is publication number 57 of the International Centre for Geohazards. The experiments could not have been performed without help from the laboratory staff and students at St. Anthony Falls Laboratory, University of Minnesota. In particular, G. Parker is acknowledged for his valuable contributions during planning as well as execution of the experiments. Thanks to the staff at the Geotechnical Department of the Norwegian University of Science and Technology for valuable help with the pressure transducers and filters. Help from D. Issler with setting up the experiment and for his useful comments on the article was greatly appreciated. The manuscript benefited from careful reviews by K. Høeg and B.D. Bornhold.
- debris flow
- flow behaviour
- gravity flow
- laboratory experiment
- pore pressure measurements