Details of Award
NERC Reference : NER/A/S/2003/00439
Shocks, dead zones and vacua in avalanches, debris-flows, rockfalls and pyroclastic flows
Grant Award
- Principal Investigator:
- Professor N Gray, The University of Manchester, Mathematics
- Grant held at:
- The University of Manchester, Mathematics
- Science Area:
- Freshwater
- Earth
- Overall Classification:
- Earth
- ENRIs:
- Natural Resource Management
- Environmental Risks and Hazards
- Science Topics:
- Earth Surface Processes
- Sediment/Sedimentary Processes
- Hydrological Processes
- Glacial & Cryospheric Systems
- Geohazards
- Earth Engineering
- Abstract:
- Avalanches, debris flows, rockfalls and pyroclastic flows are globally significant natural hazards, which share a number of common features, such as the formation of shocks, dead-zones and vacua. Shocks are regions in which there are rapid changes in the flow height and velocity and are generated when the avalanche flows past an obstacle. If the obstacle has a blunt face a region of the material may be brought completely to rest, to form a stationary region called a dead-zone that ultimately forms a permanent deposit after the rest of the avalanche has passed by. On the lee-side of obstacles grain-free vacuum regions can form and these are of great practical significance because they can be used to protect buildings and structures from natural hazards. Avalanches exhibit weak scale-dependence over a very broad range. This means that the dynamics of an avalanche that flows down a mountain-side is essentially the same as that of an avalanche that forms on the centimetre scale, such as when you pour cornflakes into a bowl at breakfast. This proposal exploits this 'scale-invariance' to use small scale experiments to understand processes in geophysical scale events that are much more difficult and dangerous to observe. The link between the small and large scales is provided by field data that has been collected from two avalanches that generated 'oblique' shocks at a deflecting dam in Flateyri in northwestern Iceland. Oblique shocks are interesting features in their own right, but they also provide useful constitutive information, which we will use to test whether the internal stress field is consistent with a simple hydrostatic theory or whether more complex granular theories are required. Constitutive information will also be collected from small scale experiments past a variety of obstacles and comparisons will be made with the predictions from mathematical models, which will be developed and extended as part of the project. A particularly exciting feature of the work, where we expect many new phenomena to be observed, is the investigation of interacting shocks, dead-zones and vacua that are generated by multiple obstacles.
- NERC Reference:
- NER/A/S/2003/00439
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £152,704
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £95,523 | £5,254 | £7,985 | £43,941 |
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