Resumen

BLANCO, Armando; RODRIGUEZ, Carmen  y  GARCIA, Reinaldo. Can we accurately use laboratory-scale rheological parameters to model field-scale debris flow?. Rev. Fac. Ing. UCV [online]. 2009, vol.24, n.1, pp.45-55. ISSN 0798-4065.

Numerical models are often used to predict debris flow behavior at field scale. However, rheological parameters that govern fluid behavior are difficult to obtain using conventional rheometers. Generally, laboratory experiments are combined with mathematical modeling to calibrate rheological models. Then, the laboratory-calibrated numerical model is used to predict debris flow behavior at field scales. This paper shows that extrapolating results from laboratory experiments to field scales may lead to non-accurate predictions. Usually, laboratory flumes are just a few meters long, while an actual debris flow event in the field can involve scales of several kilometers. Therefore, a rheological model that provides good results in the laboratory, does not necessarily replicate a field event. In this paper, we analyzed field-scale predictions using numerical models whose rheological parameters are adjusted from laboratory experiments. Results from water flow in large scale experimental facilities were simulated by different rheological models. Rheological parameters were adjusted using a mathematical model. Results showed that adjusting specific parameters, all rheological models could be adequately calibrated when using laboratory data for different flow conditions, even though water was the fluid used in laboratory experiences. However, when models were applied to a field event, there were significant differences in their predictions. This suggests that adjusting rheological parameters by using laboratory scale experiments may not be applicable for field-scale debris flow simulations.

Palabras clave : Debris flows; Resistance laws; Rheological behavior of mixtures; Numerical simulation; Channel slope.