posted on 2015-11-26, 12:05authored byS. Uhlemann, Alister SmithAlister Smith, J. Chambers, Neil Dixon, Tom DijkstraTom Dijkstra, Edward Haslam, Philip Meldrum, A. Merritt, David Gunn, Jonathan Mackay
A landslide complex in the Whitby Mudstone Formation at Hollin Hill, North Yorkshire, UK is periodically re-activated in response to rainfall-induced pore-water pressure fluctuations. This paper compares long-term measurements (i.e., 2009 – 2014) obtained from a combination of monitoring techniques that have been employed together for the first time on an active landslide. The results highlight the relative performance of the different techniques, and can provide guidance for researchers and practitioners for selecting and installing appropriate monitoring techniques to assess unstable slopes. Particular attention is given to the spatial and temporal resolution offered by
the different approaches that include: Real Time Kinematic-GPS (RTK-GPS) monitoring of a ground surface marker array, conventional inclinometers, Shape Acceleration Arrays (SAA), tilt meters, active waveguides with Acoustic Emission (AE) monitoring, and piezometers. High spatial resolution
information has allowed locating areas of stability and instability across a large slope. This has enabled identification of areas where further monitoring efforts should be focused. High temporal resolution information allowed the capture of S’-shaped slope displacement-time behaviour (i.e.
phases of slope acceleration, deceleration and stability) in response to elevations in pore-water pressures. This study shows that a well-balanced suite of monitoring techniques that provides high temporal and spatial resolution on both measurement and slope scale is necessary to fully understand failure and movement mechanisms of slopes. In the case of the Hollin Hill landslide it
enabled detailed interpretation of the geomorphological processes governing landslide activity. It highlights the benefit of regularly surveying a network of GPS markers to determine areas for installation of movement monitoring techniques that offer higher resolution both temporally and spatially. The small sensitivity of tilt meter measurements to translational movements limited the
ability to record characteristic ‘S’-shaped landslide movements at Hollin Hill, which were identified using SAA and AE measurements. This high sensitivity to landslide movements indicates the applicability of SAA and AE monitoring to be used in early warning systems, through detecting and quantifying accelerations of slope movement.
Funding
This paper was funded by The Engineering and Physical Sciences Research Council (EPSRC), UK.
History
School
Architecture, Building and Civil Engineering
Published in
Geomorphology
Citation
UHLEMANN, S. ...et al., 2016. Assessment of ground-based monitoring techniques applied to landslide investigations. Geomorphology, 253, pp.438–451.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC-BY 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by/4.0/
Publication date
2016
Notes
This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/