Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
North America Government
Dr James D Murff, or ‘Don’ as he prefers to be called, was born in 1941 in Houston, Texas, and raised in West University Place when it was a small bedroom community on the outskirts of town. In 1963 he obtained a Bachelor of Science and Engineering from the US Military Academy at West Point. He joined the US Army Corps of Engineers and served in Texas, Panama and Vietnam. His meritorious service in South Vietnam earned him the Bronze Star Medal and the Army Commendation Medal. Upon his return to the USA, he attended Texas A&M University from which he obtained MS and PhD degrees in 1970 and 1972. He then joined the offshore division of the Exxon Production Research Company in Houston, Texas. Throughout the years, he advanced through various levels of responsibility in offshore geotechnical and earthquake engineering. In this capacity he was responsible for planning, conducting and implementing geotechnical research; developing geotechnical specifications and design methodology for major Exxon platform installations; and consulting and troubleshooting for Exxon affiliates. He eventually achieved the position of Senior Research Advisor, one of Exxon's highest technical levels. Until his retirement in 1999, Don was the goto expert and ultimate authority for all geotechnical matters for the largest publicly traded oil and gas company in the world. If Don said, ‘No’, they would not do it; if Don said, ‘Yes’, everybody felt good about doing it. In parallel with his career at Exxon, Don was very active in industry committees, particularly the American Petroleum Institute (API) Geotechnical Resource Group, of which he was a member from 1976 to 2001, and the Chairman from 1978 to 1985. He led the research project on centrifuge research for offshore piling with Prof RF Scott.
- Government > Regional Government > North America Government > United States Government (1.00)
- Government > Military > Army (1.00)
- Energy > Oil & Gas (1.00)
Abstract First-order, second-moment (FOSM) approximations provide an efficient way to assess submarine slope stability across large areas for which digital bathymetric data are available. This is demonstrated using 20m bin 3D seismic seafloor data for a deepwater area with typical geotechnical soil properties. Results are obtained in terms of a factor of safety mean and standard deviation for an infinite slope with pseudo-static seismic loading. From this the probability of sliding is calculated for each bin without the computational burden of Monte Carlo or other iterative methods. Because these types of probabilistic model incorporate parameter uncertainty into their input and output, they can be used to support decisions about the value of additional data collection, or justify more sophisticated analyses that may help to reduce output uncertainties. In addition to providing detailed maps of the probability of sliding, the analysis produces global statistics that allow insight into the broader response of the system to seismic shaking. 1. Introduction Evaluation of deepwater geohazards commonly entails assessment of slope stability either to understand the geologic history of a project area, or to anticipate the risk associated with future events, such as major earthquakes. This can be done qualitatively based on the presence or absence of past landslide deposits; semi-quantitatively using simple measures such as slope angle or gradient; or quantitatively using limit equilibrium slope stability analysis (e.g. Mackenzie et al., 2010). Limit equilibrium methods are widely known and attractive because they integrate the essential physics of sliding and allow evaluation of rare or unprecedented conditions (for example the effects of a large future earthquake). However, they also require specification of geotechnical variables, such as sediment shear strength, thickness and unit weight, in addition to some description of slope geometry (minimally the slope angle).
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.94)
ABSTRACT Subsea trenching operations are routinely performed to provide protection for pipelines, umbilicals and power cables. The increase in offshore wind farm developments and the focus on environmental impact from new regulatory bodies and the public have focused attention on trenching operations. This paper reviews the methods of trenching routinely used and their impact on the seabed. Two case studies are presented showing the actual and modelled effects of trenching operations. Consideration is given on methods that could be used for real-time monitoring of trenching operations. 1. Introduction There is frequently a requirement to bury pipelines and cables into seabed sediments to protect them from external threats. A variety of trenching techniques are used that are dependent on the seabed sediments present and the nature of the product being trenched. The trenching operations can have a potentially adverse effect on the seabed environmental conditions, through lifting sediment particles into the water column and disturbing the seabed surface sediments. This paper reviews the operation of the different trenching techniques available, including jetting, ploughing and mechanical cutting tools. It then assesses and discusses the impact of these techniques on the seabed environment. This is then placed in the context of naturally occurring events, such as sediment mobility, and anthropogenic activities, such as fishing and aggregate dredging. 2. Trenching Operations - Method and Impacts Submarine cables, umbilicals and pipelines must be protected from damage, which could be caused by accidental impact from ships anchors or trawling activities. Fatigue of products can also occur if the seabed around them is scoured by wave or tidal currents. To mitigate against these effects, pipelines, umbilicals and cables are routinely buried beneath the seabed, or lowered into an open trench that is deep enough to provide protection (Machin, 2000).
- Law > Environmental Law (1.00)
- Energy > Oil & Gas > Upstream (0.68)
- Energy > Renewable > Wind (0.55)
- Government > Regional Government > North America Government > United States Government (0.47)
ABSTRACT The importance of mitigating the impact of offshore renewable energy developments and their associated infrastructure on the marine historic environment has been widely recognised by the Crown Estate, developers and curators for a number of years. Over the last 15 years offshore renewable schemes have given archaeologists access to large areas of seafloor that would not have otherwise been subject to archaeological investigation. Marine archaeology is a constantly evolving field, and understanding of it is increasing as more offshore developments take place. The initial assessment of the archaeological resource within a development area begins at the Environmental Impact Assessment (EIA) stage. As the project progresses the archaeological mitigation works are covered by a Written Scheme of Investigation (WSI) setting out the need for further, targeted archaeological assessments using data acquired during the site investigation process. This allows archaeologists to refine their understanding of what material is present within the development area and to adjust their advice accordingly. This paper shows examples of how archaeological sites are identified and studied using standard site investigation techniques, along with possible mitigation strategies. 1. Introduction Increasingly over the last 15 years, marine planning within UK waters has routinely considered the potential impact of developments on the maritime archaeological resource, termed ‘heritage assets’ or ‘archaeological assets’ in legislation. These assets range from the remains of vessels, aircraft and associated debris to historic landscapes, as well as remains deriving from the history of the British Isles and its inhabitants' exploitation of the sea (Roberts and Trow, 2002). As a result of the 2009 Act, as well as the Marine (Scotland) Act 2010 and the Northern Ireland Marine Bill, new licensing bodies for marine planning are being introduced across the UK that will further increase the protection of historic assets (HM Government, 2011).
- Europe > United Kingdom > Scotland (0.24)
- Europe > United Kingdom > Northern Ireland (0.24)
- Energy > Renewable (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.56)
- Government > Regional Government > Europe Government > United Kingdom Government (0.48)