The development and utilisation of engineering geological models is at the forefront of GRS’s approach to ground problems. GRS have extensive experience in the use of engineering geology and engineering geomorphology to develop geological, ground and design models for a wide range of civil engineering applications in a variety of geological and geographical settings. Models developed to characterise, quantify and analyse ground conditions for civil engineering applications allow for the documentation of uncertainty (e.g. risk registers) and enable focused site investigations at key stages of a given project. This ensures that potential ground risks are identified and assessed, minimising the occurrence of “unforeseen” ground conditions.
Re-examination of previous ground investigation by GRS during a tender proposal revealed (a) cohesive fine grained colluvium (typically a silty clay), probably originating from slope wash or numerous small landslide deposits over considerable time; and (b) clastic colluvium comprising cobbles and boulders, possibly representing debris from a large magnitude, high energy, relatively rapid landslide event(s). The clastic colluvium was >9.5m thick and in parts was interbedded with fine material suggesting that there may have been more than one episode of failure. GRS's re-interpretation of original data provided the bidding contractor additional critical information indicating that the site in question was potentially considerably more problematic than the geotechnical information provided implied.
Parry, S., Hart, J.R. & Moore, A.J. (2009). Reducing Uncertainty in Natural Terrain Hazard Studies: the Role of the Engineering Geologist. Proceedings of the 29th Annual Seminar, Geotechnical Division, Hong Kong Institution of Engineers. pp 61-70.
http://www.hkieged.org/download/proceeding.pdf
Where no information is available GRS are able to develop models from aerial photograph interpretation and/or field reconnaissance enabling a rapid evaluation of the potential risks at a site.
Parry, S. & Ng, K.C. (in press). The Assessment of Landslide Risk from Natural Slopes in Hong Kong: An Engineering Geological Perspective. Quarterly Journal of Engineering Geology & Hydrogeology.