Landslide characterization using P- and S-wave seismic refraction tomography: the importance of elastic moduli

Uhlemann, S.; Hagedorn, S.; Dashwood, B.; Maurer, H.; Gunn, D.; Dijkstra, T.; Chambers, J.. 2016 Landslide characterization using P- and S-wave seismic refraction tomography: the importance of elastic moduli. Journal of Applied Geophysics, 134. 64-76. https://doi.org/10.1016/j.jappgeo.2016.08.014

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Official URL: http://dx.doi.org/10.1016/j.jappgeo.2016.08.014

Abstract/Summary

In the broad spectrum of natural hazards, landslides in particular are capable of changing the landscape and causing significant human and economic losses. Detailed site investigations form an important component in the landslide risk mitigation and disaster risk reduction process. These investigations usually rely on surface ob- servations, discrete sampling of the subsurface, and laboratory testing to examine properties that are deemed representative of entire slopes. Often this requires extensive interpolations and results in large uncertainties. To compliment and extend these approaches, we present a study from an active landslide in a Lias Group clay slope, North Yorkshire, UK, examining combined P- and S-wave seismic refraction tomography (SRT) as a means of providing subsurface volumetric imaging of geotechnical proxies. The distributions of seismic wave velocities determined fromSRT at the study site indicated zones with higher porosity and fissure density that are interpreted to represent the extent and depth of mass movements and weathered bedrock zones. Distinguishing the lithological units was facilitated by deriving the Poisson's ratio fromthe SRT data as saturated clay and partially saturated sandy silts showed distinctively different Poisson's ra- tios. Shear and Young's moduli derived from the SRT data revealed the weak nature of the materials in active parts of the landslide (i.e. 25 kPa and 100 kPa respectively). The SRT results are consistent with intrusive (i.e. cone penetration tests), laboratory, and additional geoelectrical data from this site. This study shows that SRT forms a cost-effective method that can significantly reduce uncertainties in the conceptual ground model of geotechnical and hydrological conditions that govern landslide dynamics.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.jappgeo.2016.08.014
ISSN:	09269851
NORA Subject Terms:	Earth Sciences
Date made live:	09 Jan 2017 10:00 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/515701

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.jappgeo.2016.08.014

ISSN:

09269851

NORA Subject Terms:

Earth Sciences

Date made live:

09 Jan 2017 10:00 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/515701