Abstract
Flexible barriers undergo large deformation to extend the impact duration, and thereby reduce the impact load of geophysical flows. The performance of flexible barriers remains a crucial challenge because there currently lacks a comprehensive criterion for estimating impact load. In this study, a series of centrifuge tests were carried out to investigate different geophysical flow types impacting an instrumented flexible barrier. The geophysical flows modelled include covered in this study include flood, hyperconcentrated flow, debris flow, and dry debris avalanche. Results reveal that the relationship between the Froude number, Fr, and the pressure coefficient α strongly depends on the formation of static deposits called dead zones which induce static loads and whether a run-up or pile-up impact mechanism develops. Test results demonstrate that flexible barriers can attenuate peak impact loads of flood, hyperconcentrated flow, and debris flow by up to 50% compared to rigid barriers. Furthermore, flexible barriers attenuate the impact load of dry debris avalanche by enabling the dry debris to reach an active failure state through large deformation. Examination of the state of static debris deposits behind the barriers indicates that hyperconcentrated and debris flows are strongly influenced by whether excessive pore water pressures regulate the depositional process of particles during the impact process. This results in significant particle rearrangement and similar state of static debris behind rigid barrier and the deformed full-retention flexible barrier, and thus the static loads on both barriers converge.
Similar content being viewed by others
References
Armanini A (1997) On the dynamic impact of debris flows. In Recent developments on debris flows (pp. 208–226). Springer, Berlin Heidelberg
Ashwood W, Hungr O (2016) Estimating the total resisting force in a flexible barrier impacted by a granular avalanche using physical and numerical modeling. Can Geotech J. doi:10.1139/cgj-2015-0481
Bagnold RA (1954) Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear. Proc R Soc London A Math Phys Eng Sci 225(1160):49–63
Bugnion L, Wendeler C (2010) Shallow landslide full-scale experiments in combination with testing of a flexible barrier. In Monitoring, simulation, prevention and remediation of dense and debris flows III, pp 161–173
Choi CE, Au-Yeung SCH, Ng CWW, Song D (2015) Flume investigation of landslide granular debris and water runup mechanisms. Géotech Lett 5:28–32
Cui P, Zeng C, Lei Y (2015) Experimental analysis on the impact force of viscous debris flow. Earth Surf Process Landf. doi:10.1002/esp.3744
DeNatale JS, Iverson RM, Major JJ, LaHusen RG, Fiegel GL, Duffy JD (1999) Experimental testing of flexible barriers for containment of debris flows. US Department of the Interior, US Geological Survey
Gray JMNT, Tai YC, Noelle S (2003) Shock waves, dead zones and particle-free regions in rapid granular free-surface flows. J Fluid Mech 491:161–181
Hübl J, Suda J, Proske D, Kaitna R, Scheidl C (2009) Debris flow impact estimation. In Proceedings of the 11th International Symposium on Water Management and Hydraulic Engineering, pp. 1–5. Ohrid, Macedonia
Hungr O, Morgan GC, Kellerhals R (1984) Quantitative analysis of debris torrent hazards for design of remedial measures. Can Geotech J 21(4):663–677
Iverson RM (1997) The physics of debris flows. Rev Geophys 35(3):245–296
Iverson RM (2003) How should mathematical models of geomorphic processes be judged? In: Wilcock PR, Iverson RM (eds) Prediction in geomorphology. American Geophysical Union, Washington
Iverson RM (2015) Scaling and design of landslide and debris-flow experiments. Geomorphology 244:9–20
Iverson RM, George DL (2014) A depth-averaged debris-flow model that includes the effects of evolving dilatancy. I. Physical basis. Proc R Soc London A Math Phys Eng Sci 470(2170):20130819
Iverson RM, George DL (2016) Modelling landslide liquefaction, mobility bifurcation and the dynamics of the 2014 Oso disaster. Geotechnique 66:175–187
Kwan JSH (2012) Supplementary technical guidance on design of rigid debris-resisting barriers. GEO Report No. 270. Geotechnical Engineering Office, HKSAR Government
Kwan JSH, Cheung RWM (2012) Suggestion on design approaches for flexible debris-resisting barriers. Discussion note DN1/2012. Geotechnical Engineering Office, HKSAR Government
Kwan JSH, Chan SL, Cheuk JCY, Koo RCH (2014) A case study on an open hillside landslide impacting on a flexible rockfall barrier at Jordan Valley, Hong Kong. Landslides 11(6):1037
Margreth S, Roth A (2008) Interaction of flexible rockfall barriers with avalanches and snow pressure. Cold Reg Sci Technol 51(2):168–177
MLR (2006) Specification of geological investigation for debris flow stabilization. DZ/T 0220-2006, National Land Resources Department, China, 32 p (in Chinese)
Ng CWW (2014) The state-of-the-art centrifuge modelling of geotechnical problems at HKUST. J Zhejiang Univ Sci A 15(1):1–21
Ng CWW, Choi CE, Su Y, Kwan JSH, Lam C (2016a) Large-scale successive boulder impacts on a rigid barrier shielded by gabions. Can Geotech J 53(10):1688–1699
Ng CWW, Song D, Choi CE, Koo RCH, Kwan JSH (2016b) A novel flexible barrier for landslide impact in centrifuge. Géotech Lett:221–225
Ng CWW, Song D, Choi CE, Liu LHD, Kwan JSH, Koo RCH, Pun W (2016c) Impact mechanisms of granular and viscous flows on rigid and flexible barriers. Can Geotech J 54(2):188–206
Pierson TC (2005) Hyperconcentrated flow-transitional process between water flow and debris flow. In Debris-flow hazards and related phenomena (pp. 159–202). Springer, Berlin Heidelberg
Peregrine DH (2003) Water-wave impact on walls. Annu Rev Fluid Mech 35(1):23–43
Savage SB, Hutter K (1989) The motion of a finite mass of granular material down a rough incline. J Liq Mech 199:177–215
Schofield AN (1980) Cambridge geotechnical centrifuge operations. Geotechnique 30(3):227–268
Sasiharan N, Muhunthan B, Badger TC, Shu S, Carradine DM (2006) Numerical analysis of the performance of wire mesh and cable net rockfall protection systems. Eng Geol 88(1):121–132
Savage SB (1984) The mechanics of rapid granular flows. Adv Appl Mech 24:289–366
Song D, Ng CWW, Choi CE, GGD Z, Kwan JSH, Koo RCH (2017a) Influence of debris flow solid fraction on rigid barrier impact. Can Geotech J. doi:10.1139/cgj-2016-0502
Takahashi T (2014) Debris flow: mechanics, prediction and countermeasures. CRC Press, Boca Raton
Take WA (2015) Thirty-sixth Canadian geotechnical colloquium: advances in visualization of geotechnical processes through digital image correlation. Can Geotech J 52(9):1199–1220
Wendeler C, McArdell BW, Rickenmann D, Volkwein A, Roth A, Denk M (2006) Field testing and numerical modeling of flexible debris flow barriers. In Proceedings of international conference on physical modelling in geotechnics, Hong Kong
Wendeler C, Volkwein A, Denk M, Roth A, Wartmann S (2007) Field measurements used for numerical modelling of flexible debris flow barriers. In CL Chen, JJ major (eds). Proceedings of Fourth International Conference on Debris Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, Chengdu, China, 10–13 September 2007. Pp. 681–687
Wendeler C (2016) Debris flow protection systems for mountain torrents—basic principles for planning and calculation of flexible barriers. WSL Bericht 44. ISSN 2296-3456
Wendeler C, Volkwein A (2015) Laboratory tests for the optimization of mesh size for flexible debris-flow barriers. Nat Hazards Earth Syst Sci 15(12):2597–2604
White DJ, Take WA, Bolton MD (2003) Soil deformation measurement using particle image velocimetry (PIV) and photogrammetry. Geotechnique 53(7):619–631
WSL (2009) Full-scale desting and dimensioning of flexible debris flow barriers. Technical report 1–22. WSL, Birmensdorf
Zhou GGD, Ng CWW (2010) Dimensional analysis of natural debris flows. Can Geotech J 47(7):719–729
Acknowledgements
The authors are grateful for financial support from research grant T22-603/15-N provided by the Research Grants Council of the Government of Hong Kong SAR, China and the HKUST Jockey Club Institute for Advanced Study for their support. The authors acknowledge the support from the Chinese Academy of Sciences (CAS) Pioneer Hundred Talents Program (Song Dongri) and the Youth Innovation Promotion Association, CAS. Also financial supports from the National Natural Science Foundation of China (grant no. 11672318) and the International partnership program of Chinese Academy of Sciences (grant no. 131551KYSB20160002) are greatly appreciated.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Song, D., Choi, C.E., Ng, C.W.W. et al. Geophysical flows impacting a flexible barrier: effects of solid-fluid interaction. Landslides 15, 99–110 (2018). https://doi.org/10.1007/s10346-017-0856-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10346-017-0856-1