Erosional effects on runout of fast landslides, debris flows

The mechanism of mass changes in debris transportation process is an important topic in the study of fast landslides, debris flows and avalanches. Basal erosion is recognised as a dynamic interaction between the original moving material and the entrained basal topsoil shearing along their non-slip contact surface. In this paper we propose a new concept of yield rate and establish the erosional relationship to bridge these two systems. A pertinent mathematical model and numerical implementation are formulated. Parametric numerical experiments are conducted to compare the erosional effects. The simulated results are consistent with available experimental and field observations. The influence of the involvement of the erosive material on runout behaviour and the global mobility of the moving material are elucidated. The proposed method is then employed to analyse a recent debris flow event in northern Italy. The excellent match to the field data gives it a plausible potential application to the analysis of this type of gravity-driven flow with significant erosion. Defined in a dimensionless form, the proposed yield rate can be estimated conveniently in general geotechnical practices.

[1]  Cf Lee,et al.  CAUSATIVE MECHANISMS OF RAINFALL-INDUCED FILL SLOPE FAILURES , 2004 .

[2]  P. Frattini,et al.  Soil slips and debris flows on terraced slopes , 2003 .

[3]  Giovanni B. Crosta,et al.  Replay of the 1987 Val Pola Landslide, Italian Alps , 2004 .

[4]  Kyoji Sassa,et al.  Geotechnical model for the motion of landslides , 1988 .

[5]  Oldrich Hungr,et al.  An unusually large debris flow at Hummingbird Creek, Mara Lake, British Columbia , 2000 .

[6]  Kolumban Hutter,et al.  Shock-capturing and front-tracking methods for granular avalanches , 2015, 1501.04756.

[7]  Richard M. Iverson,et al.  Granular avalanches across irregular three-dimensional terrain: 1. Theory and computation , 2004 .

[8]  R. Fannin,et al.  Debris flows: some physical characteristics and behaviour , 1993 .

[9]  C. F. Lee,et al.  Runout Analysis of Slurry Flows with Bingham Model , 2002 .

[10]  J. Warburton,et al.  Anatomy of a Pennine peat slide, Northern England , 2003 .

[11]  R J Fannin,et al.  An empirical-statistical model for debris flow travel distance , 2001 .

[12]  Donald Gabriëls.  The effect of slope length on the amount and size distribution of eroded silt loam soils: short slope laboratory experiments on interrill erosion. , 1999 .

[13]  Matthias Jakob,et al.  Two Debris Flows with Anomalously High Magnitude , 1997 .

[14]  J. Corominas.  Evidence of basal erosion and shearing as mechanisms contributing the development of lateral ridges in mudslides, flow-slides, and other flow-like gravitational movements , 1995 .

[15]  Kolumban Hutter,et al.  Unconfined flow of granular avalanches along a partly curved surface. II. Experiments and numerical computations , 1994, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[16]  Giovanni B. Crosta,et al.  CONTINUUM NUMERICAL MODELLING OF FLOW-LIKE LANDSLIDES , 2006 .

[17]  W. Lick,et al.  Measurements of Erosion of Undisturbed Bottom Sediments with Depth , 1996 .

[18]  R. Govindaraju.  Effective erosion parameters for slopes with spatially varying properties , 1998 .

[19]  O. Hungr,et al.  A model for the analysis of rapid landslide motion across three-dimensional terrain , 2004 .

[20]  D. M. Cruden,et al.  MOMENTUM TRANSFER AND FRICTION IN THE DEBRIS OF ROCK AVALANCHES , 1989 .

[21]  H. Erlichson.  A Mass-Change Model for the Estimation of Debris-Flow Runout, a Second Discussion: Conditions for the Application of the Rocket Equation , 1991, The Journal of geology.

[22]  S. Savage,et al.  The motion of a finite mass of granular material down a rough incline , 1989, Journal of Fluid Mechanics.

[23]  C. Kranenburg,et al.  Erosion of Fluid Mud Layers. II: Experiments and Model Validation , 1997 .

[24]  Kolumban Hutter,et al.  Gravity-driven free surface flow of granular avalanches over complex basal topography , 1999, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[25]  Hajime Nakagawa,et al.  Routing Debris Flows with Particle Segregation , 1992 .

[26]  R. W. Fleming,et al.  Mobilization of debris flows from soil slips, San Francisco Bay region, California , 1987 .

[27]  Mark A. Nearing,et al.  Soil Detachment by Shallow Flow at Low Slopes , 1991 .

[28]  H Chen,et al.  Numerical simulation of debris flows , 2000 .

[29]  Helmut J. Körner,et al.  Reichweite und Geschwindigkeit von Bergstürzen und Fließschneelawinen , 1976 .

[30]  John T. Germaine,et al.  EROSIONAL AND MECHANICAL STRENGTHS OF DEPOSITED COHESIVE SEDIMENTS , 1998 .

[31]  O. Hungr.  A Mass Change Model for the Estimation of Debris Flow Runout: A Discussion , 1990, The Journal of Geology.

[32]  Oldrich Hungr,et al.  A model for the runout analysis of rapid flow slides, debris flows, and avalanches , 1995 .

[33]  C. F. Lee,et al.  A dynamic model for rainfall-induced landslides on natural slopes , 2003 .

[34]  Comparison of Debris Flow Modelling Approaches , 1997 .

[35]  Jesse D. Roberts,et al.  Effects of Particle Size and Bulk Density on Erosion of Quartz Particles , 1998 .

[36]  Oldrich Hungr,et al.  Quantitative analysis of debris torrent hazards for design of remedial measures , 1984 .

[37]  G. R. Foster,et al.  closed-form soil erosion equation for upland areas , 1972 .

[38]  William Z. Savage,et al.  A Mass-Change Model for the Estimation of Debris-Flow Runout , 1988, The Journal of Geology.

[39]  Gokmen Tayfur,et al.  Modeling Two-Dimensional Erosion Process over Infiltrating Surfaces , 2001 .

[40]  Richard M. Iverson,et al.  Flow of variably fluidized granular masses across three‐dimensional terrain: 1. Coulomb mixture theory , 2001 .