Hearn G.,URS Scott Wilson Ltd |
Wise D.,Jacobs Engineering |
Hart A.,URS Scott Wilson Ltd |
Morgan C.,URS Scott Wilson Ltd |
O'Donnell N.,9 Elm Walk
Quarterly Journal of Engineering Geology and Hydrogeology | Year: 2012
The Sakhalin Energy Investment Company Ltd (SEIC) Sakhalin II Phase 2 oil and gas pipeline corridor is 782 km in length, and extends from landfall sites in the north of the island to a liquefied natural gas plant and oil export terminal in the south. For c. 120 km this alignment crosses the Makarov Mountains, an approximately north-south-orientated grouping of ridges and valleys formed in Cretaceous mudstones, Tertiary siltstones, sandstones, coal measures, lavas and tuffs. Situated on the NW Pacific rim, the island is prone to seismic activity, and the design and construction of the pipelines' alignment has had to take into consideration a number of existing landslides (more than 400 in total). Additionally, the continuing seismic hazard, combined with slope toe erosion by rivers and high groundwater tables brought about by spring snow melt and summer rains, creates a potential for first-time landslides to occur during the 50 year operational period of the pipelines. To assess where such failures might take place a study was undertaken that combined back-analysis and sensitivity analysis, landslide susceptibility analysis (including factor analysis) and qualitative evaluation. The qualitative evaluation allowed a judgement-based assessment to be included in the identification and prioritization of potential future first-time failure areas. Ground truthing was then undertaken in the areas of highest susceptibility, and generally supported the findings of the analysis. In c. 50% of these cases the potential for landslide initiation was considered to be sufficiently high to warrant intervention, in terms of ground investigation, slope movement and groundwater monitoring, or engineering mitigation. The study highlights the uncertainties that exist when undertaking exercises such as these where geotechnical information is insufficient to carry out rigorous modelling and where broad geological and geographical assessments have to be made in order to yield the required outputs. © 2012 The Geological Society of London.
Hearn G.,URS Scott Wilson Ltd.
Landslide Science and Practice: Social and Economic Impact and Policies | Year: 2013
Landslides pose a continuing and increasing threat to the management of rural infrastructure in many countries. In many parts of Asia this threat is compounded by limited resources and budgets and limited knowledge of ground conditions to develop and manage sustainable solutions. A 3-year programme is described that aimed to strengthen capacity in the road sector of Laos in order to manage and mitigate against landslide hazards. Trial slope stabilisation and road reinstatement measures were designed and constructed and best practice manuals produced as an aid to future practice and as a means of focusing capacity building through training. Workshops, hands-on secondments and trainer-training approaches were used to maximise the take-up of these outputs and to ensure sustainability for future applications. © Springer-Verlag Berlin Heidelberg 2013.
Hart M.B.,University of Plymouth |
Boulton S.J.,University of Plymouth |
Hart A.B.,URS Scott Wilson Ltd |
Leighton A.D.,University of Plymouth
Geoscience in South-West England | Year: 2011
Fortescue William Millett (1833-1915) was one of the leading micropalaeontologists of the late 19th Century. His work concentrated on modern and living foraminifera, some of which were collected from the marine sediments around Cornwall and Devon. He also studied the marine clays of the St Erth Formation, which contain a distinctive and diverse assemblage of foraminifera and Ostracoda together with some enigmatic bolboformid-like microfossils. The presence of these Plio-Pleistocene sands and clays perched on the Palaeozoic basement provides evidence of sea levels significantly higher than the present day.
Hearn G.J.,URS Scott Wilson Ltd. |
Hart A.B.,URS Scott Wilson Ltd.
Developments in Earth Surface Processes | Year: 2011
Landslides pose a significant risk to rural communities and infrastructure in hilly and mountainous regions and, with the expansion of development into these areas, levels of hazard and risk are increasing. Great advances have been made in the last two decades in the development of techniques to assess and map landslide susceptibility, hazard and risk, but the most reliable of these are dependent upon a level of event and impact data that are characteristically not available in many parts of the world. Where land use and infrastructure planning and engineering design are required to be carried out over relatively short time frames, and in areas where data are scarce or non-existent, a pragmatic approach is required to yield the desired outputs, maximising contributions from geological, geomorphological and geotechnical interpretation. Three case studies are presented, from Nepal, Russia and Cyprus. In each case, data were insufficient to yield truly quantified hazard and risk assessment. Geomorphological assessment, principally through the use and interpretation of geomorphological mapping and inventories, provided the means by which project outputs could be developed to match end-user requirements. Comparisons are made between the methodology developed in each case with the procedural guidelines contained in Fell et al. (2008). It is concluded that, in most project applications, data limitations mean that it is not possible to yield landslide hazard and risk assessment much beyond the class of basic and intermediate according to the definitions provided. © 2011 Elsevier B.V.