Patterns of movement in the Ventnor landslide complex, Isle of Wight, southern England
Tóm tắt
The patterns of ground movement were monitored within a large, deep-seated landslide complex at Ventnor in southern England, between May 1998 and June 2002 using automated crackmeters, settlement cells and vibrating wire piezometers. It was found that the landslide maintains a state of marginal instability, such that it is subject to continual very slow deformation. Movement is primarily on a low-angled basal shear surface at >90 m depth. The movement record shows a series of distinct deformation patterns that vary as groundwater conditions change. Continuous slow deformation occurs across the landslide complex at rates of between 5 and 10 mm/year. The background pattern of movement does not appear to correlate with local porewater pressure. Periods of more rapid movement (reaching up to c. 34 mm/year during the monitoring period) were associated with a period of elevated groundwater, although the relationship between movement rate and porewater pressure was complex. The patterns of movement and the landslide geometry suggest that the likelihood of a rapid, catastrophic failure is low. Future episodes of faster movement are likely during periods when porewater pressures at the basal shear surface are elevated above a critical threshold. Whilst the resulting surface deformation damages the town, it is unlikely to occur rapidly without significant changes to the landslide hydrogeology or the stress state within the landslide.
Tài liệu tham khảo
Allison R, Brunsden D (1990) Some mudslide movement patterns. Earth Surf Process Landf 15:297–311
Anonymous (2013) http://onthewight.com/2013/03/08/ground-movement-damage-on-ventnor-roads-to-be-tackled/Accessed on 16 Oct 2014
Casagli N, Filippo C, Ventisette D, Luzi G (2010) Monitoring, prediction, and early warning using ground based radar interferometry. Landslides 7:291–301
Chandler MP (1984) The coastal landslides forming the Undercliff of the Isle of Wight. Ph.D. thesis (unpublished), Imperial College, University of London
Corominas J, Moya J, Ledesma A, Lloret A, Gili JA (2009) Prediction of ground displacements and velocities from groundwater level changes at the Vallcebre landslide (Eastern Pyrenees, Spain). Landslides 2(2):83–96
Du J, Yin K, Lacasse S (2013) Displacement prediction in colluvial landslides, Three Gorges Reservoir, China. Landslides 10(2):203–218
Dunnicliff J (1993) Geotechnical instrumentation for monitoring field performance. Wiley, Chichester, p 608
Fukuzono T (1990) Recent studies on the time prediction of slope failures. Landslide News 4:9–12
Geomorphological Services Limited (1987) Review of research into landsliding in Great Britain. Series A: regional review of landsliding—regional atlases of country maps at 1:25,000 scale, regional reports. Report to the Department of the Environment
Halcrow (2006) Ventnor Undercliff, Isle of Wight coastal instability risk: interpretative report and quantitative risk analysis. Technical report to the Isle of Wight Council
Hutchinson JN (1987) Some coastal landslides of the southern Isle of Wight. In: Barber KE (ed) Wessex and the Isle of Wight. Field guide. Quaternary Research Association, Cambridge, pp 123–135
Hutchinson JN, Bromhead EN (2002) Keynote paper: Isle of Wight landslides. In: McInnes RG, Jakeways J (eds) Instability planning and management: seeking sustainable solutions to ground movement problems, Proceedings of International Conference, Ventnor. Thomas Telford, London, pp 3–70
Hutchinson JN, Bromhead EN, Chandler MP (1991) Investigations of the landslides at St Catherines Point, Isle of Wight. In: R.J. Chandler (ed), International conference on slope stability engineering—development and applications, London: Thomas Telford. pp. 213–218
Lee EM, Moore R (1991) Coastal landslip potential assessment: Isle of Wight Undercliff, Ventnor, Technical report, Department of the Environment
Massey C, Petley DN, McSaveney M (2013) Patterns of movement in reactivated landslides. Eng Geol 159:1–19
McInnes RG (2000) Managing ground instability in urban areas: a guide to best practice. IW Centre for the Coastal Environment
Moore R, Brunsden D (1996) A physico-chemical effects on the behaviour of a coastal mudslide. Geotechnique 46(2):259–278
Moore R, Lee EM, Clark AR (1995) The Undercliff of the Isle of Wight: a review of ground behaviour. Cross Publishing, London
Moore R, Carey JM, McInnes RG, Houghton JEM (2007a) Climate change, so what? Implications for ground movement and landslide event frequency in the Ventnor Undercliff, Isle of Wight. In: McInnes RJ, Jakeways J, Fairbank H, Mathie E (eds) Proceedings of the international conference landslides and climate change, Ventnor Isle of Wight. Taylor & Francis, London, pp 335–344
Moore R, Turner MD, Palmer MJ, Carey JM (2007b) The Ventnor Undercliff: landslide model, mechanisms and causes, and the implications of climate change induced ground behaviour risk. In: McInnes RJ, Jakeways J, Fairbank H, Mathie E (eds) Proceedings of the international conference landslides and climate change Ventnor Isle of Wight. Taylor & Francis, London, pp 365–375
Moore R, Carey JM, McIness RG (2010) Landslide behavior and climate change: predictable consequences for the Ventnor Undercliff, Isle of Wight. Q J Eng Geol Hydrogeol 43:447–460
Ng K-Y, Petley DN (2009) A process approach towards landslide risk management in Hong Kong. Q J Eng Geol Hydrogeol 42(4):487–498
Pankow KL, Moore JR, Hale JM, Koper KD, Kubacki T, Whidden KW, McCarter MK (2014) Massive landslide at Utah copper mine generates wealth of geophysical data. GSA Today 24(1):4–9
Petley DN (2012) Remote sensing techniques and landslides. In: Clague J, Stead D (eds) Landslides types, mechanisms and modeling. Cambridge University Press, pp 159–71
Petley DN, Bulmer MHK, Murphy W (2002) Patterns of movement in rotational and translational landslides. Geology 30(8):719–722
Petley DN, Mantovani F, Bulmer MHK, Zannoni F (2005a) The interpretation of landslide monitoring data for movement forecasting. Geomorphology 66(1–4):133–147
Petley DN, Higuchi T, Petley DJ, Bulmer MH, Carey J (2005b) The development of progressive landslide failure in cohesive materials. Geology 33(3):201–204
Saito M (1965) Forecasting the time and occurrence of a slope failure. Proceedings of the 6th international conference on soil mechanics and foundation engineering. 2. pp 537–541
Saito M (1980) Semi-logarithmic representation for forecasting slope failure. Proceedings of the international symposium on landslides, 1, 321–324
Woodruff M (1986) Monitoring of ground movement in Ventnor. Unpublished report to South Wight Borough Council
Yin Y, Zheng W, Lui Y, Zang J, Li X (2010) Integration of GPS with InSAR to monitoring of the Jiaju landslide in Sichuan, China. Landslides 7(3):359–365
Zhou YD, Tham LG, Kwong AKL, Tang XW (2010) Mechanism of drying induced rebound movements in a soil slope in Sai Kung, Hong Kong. Eng Geol 116:86–94