Impact dynamics of granular debris flows based on a small-scale physical model
Christian Scheidl1, Caroline Friedl1, Lukas Reider1
1Institute of Mountain Risk Engineering (IAN), University of Natural Resources and Life Sciences, Peter-Jordan-Strasse 82, 1190 Vienna, Austria.
Acta Geotechnica
|June 24, 2024
Summary
Predicting granular debris flow impact pressure requires understanding stress anisotropy and bulk density. Accounting for these factors improves run-up height predictions in physical models, crucial for hazard assessment.
Area of Science:
- Geophysics
- Fluid Dynamics
- Geotechnical Engineering
Background:
- Granular debris flows pose significant hazards.
- Accurate prediction of impact pressure and run-up height is essential for mitigation strategies.
Purpose of the Study:
- To investigate the influence of stress anisotropy and bulk density variations on granular debris flow impact pressure.
- To evaluate existing run-up prediction models using experimental data.
Main Methods:
- Conducted 23 small-scale physical model experiments with granular debris flows.
- Measured stress anisotropy and bulk density at impact.
- Applied measurements to energy and mass/moment conservation models.
Main Results:
- Run-up heights are better predicted when considering stress anisotropy (ranging from 1.2 to 5.0) and bulk density variations (ranging from 0.8 to 2.3).
- The significance of stress anisotropy increases with Froude number in energy conservation models.
- Bulk density variations have a greater impact on mass/momentum conservation models.
Conclusions:
- Stress anisotropy and density variations are critical parameters for accurate debris flow run-up prediction.
- The choice of conservation principle (energy vs. mass/momentum) influences the relative importance of these parameters.
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