Numerical modeling using an elastoplastic-adhesive discrete element code for simulating hillslope debris flows and calibration against field experiments

Albaba, Adel; Schwarz, Massimiliano; Wendeler, Corinna; Loup, Bernard; Dorren, Luuk (2019). Numerical modeling using an elastoplastic-adhesive discrete element code for simulating hillslope debris flows and calibration against field experiments Natural Hazards and Earth System Sciences, 19(11), pp. 2339-2358. Copernicus 10.5194/nhess-19-2339-2019

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This paper presents a discrete-element-based elastoplastic-adhesive model which is adapted and tested for producing hillslope debris flows. The numerical model produces three phases of particle contacts: elastic, plastic and adhesive. A parametric study was conducted investigating the effect of model parameters and inclination angle on flow height, velocity and pressure, in order to define the most sensitive parameters to calibrate. The model capabilities of simulating different types of cohesive granular flows were tested with different ranges of flow velocities and heights. The basic model parameters, the microscopic basal friction (ϕb) and ratio between stiffness parameters √k1/k2, were calibrated using field experiments of hillslope debris flows impacting a pressure-measuring sensor. Simulations of 50 m3 of material were carried out on a channelized surface that is 41 m long and 8 m wide. The calibration process was based on measurements of flow height, flow velocity and the pressure applied to a sensor. Results of the numerical model matched those of the field data in terms of pressure and flow velocity well while less agreement was observed for flow height. Those discrepancies in results were due in part to the deposition of material in the field test, which is not reproducible in the model. Results of best-fit model parameters against selected experimental tests suggested that a link might exist between the model parameters and the initial conditions of the tested granular material (bulk density and water and fine contents). The good performance of the model against the full-scale field experiments encourages further investigation by conducting lab-scale experiments with detailed variation in water and fine content to better understand their link to the model's parameters.

Item Type:

Journal Article (Original Article)

Division/Institute:

School of Agricultural, Forest and Food Sciences HAFL > Multifunctional Forest Management

Name:

Albaba, Adel;
Schwarz, Massimiliano0000-0003-4652-8102;
Wendeler, Corinna;
Loup, Bernard and
Dorren, Luuk

Subjects:

G Geography. Anthropology. Recreation > GE Environmental Sciences

ISSN:

1684-9981

Publisher:

Copernicus

Funders:

[UNSPECIFIED] Bundesamt für Umwelt

Projects:

[UNSPECIFIED] SlideForce

Language:

English

Submitter:

Adel Albaba

Date Deposited:

21 Jan 2020 13:12

Last Modified:

18 Dec 2020 13:29

Publisher DOI:

10.5194/nhess-19-2339-2019

Additional Information:

ISSN der Printausgabe: 1561-8633

ARBOR DOI:

10.24451/arbor.10132

URI:

https://arbor.bfh.ch/id/eprint/10132

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