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Papers by Craig Allan
CivilEng
This paper examines the scour problems related to piers-on-bank bridges resulting from frequently... more This paper examines the scour problems related to piers-on-bank bridges resulting from frequently flooded and/or constricted waterways. While local scour problems for bridge piers in riverine channels have been addressed extensively in the literature, there have been few studies addressing piers-on-bank scour scenarios. A comprehensive three-dimensional finite element analysis using the element removal (ER) technique has been performed on a recently constructed bridge with an observable scour problem on multiple piers. The analysis is further extended to study the effect of “combined scour” or extensive erosion of soil between adjacent piles. Three different loading cases were considered in the study, and the results demonstrated that the effects of local and combined scours on bridge drilled shaft foundations can be significant under the combined actions of axial, lateral loads and bending moments. Specifically, the most critical case of combined scour is when maximum moment effect...
Sedimentation in Brown’s Cove of Lake Wylie, North Carolina, can be reconstructed from historical... more Sedimentation in Brown’s Cove of Lake Wylie, North Carolina, can be reconstructed from historical records, cores, heavy mineral analysis, geochemical analysis, and 210Pb data. The sedimentology and sequence stratigraphy of the cores document changing sedimentary provenance, processes, and rates. Brown’s Cove was flooded in 1924, resulting in a transgressive sequence composed dominantly of suspension load deposited between 1924 and 1983. Based on air photos and cores, distributary channels on Beaverdam Creek delta supplied sediment to prograding, coarsening-upward delta lobes composed of turbidites grading up to traction load deposits. In 1983, a delta lobe began prograding into Brown’s Cove and was abandoned ca. 1993, leading to compaction, subsidence, and a second transgression. Another distributary avulsed to the site ca. 2003, resulting in a second prograding delta lobe. Prior to flooding of Brown’s Cove, mafic-rich fluvial sediments from the southern part of the watershed were a...
JAWRA Journal of the American Water Resources Association, 2010
Journal of Environmental Engineering
Frontiers of Environmental Science Engineering in China, 2010
Water Air Soil Pollut, 1998
Hydrological Processes, Mar 18, 2007
Agu Fall Meeting Abstracts, Dec 1, 2006
Agu Fall Meeting Abstracts, Dec 1, 2007
Seasonal Snowcovers: Physics, Chemistry, Hydrology, 1987
Frontiers of Environmental Science & Engineering in China, 2009
JAWRA Journal of the American Water Resources Association, 2010
Journal of the American Water Resources Association, 2005
JAWRA Journal of the American Water Resources Association, 2014
CivilEng
This paper examines the scour problems related to piers-on-bank bridges resulting from frequently... more This paper examines the scour problems related to piers-on-bank bridges resulting from frequently flooded and/or constricted waterways. While local scour problems for bridge piers in riverine channels have been addressed extensively in the literature, there have been few studies addressing piers-on-bank scour scenarios. A comprehensive three-dimensional finite element analysis using the element removal (ER) technique has been performed on a recently constructed bridge with an observable scour problem on multiple piers. The analysis is further extended to study the effect of “combined scour” or extensive erosion of soil between adjacent piles. Three different loading cases were considered in the study, and the results demonstrated that the effects of local and combined scours on bridge drilled shaft foundations can be significant under the combined actions of axial, lateral loads and bending moments. Specifically, the most critical case of combined scour is when maximum moment effect...
Sedimentation in Brown’s Cove of Lake Wylie, North Carolina, can be reconstructed from historical... more Sedimentation in Brown’s Cove of Lake Wylie, North Carolina, can be reconstructed from historical records, cores, heavy mineral analysis, geochemical analysis, and 210Pb data. The sedimentology and sequence stratigraphy of the cores document changing sedimentary provenance, processes, and rates. Brown’s Cove was flooded in 1924, resulting in a transgressive sequence composed dominantly of suspension load deposited between 1924 and 1983. Based on air photos and cores, distributary channels on Beaverdam Creek delta supplied sediment to prograding, coarsening-upward delta lobes composed of turbidites grading up to traction load deposits. In 1983, a delta lobe began prograding into Brown’s Cove and was abandoned ca. 1993, leading to compaction, subsidence, and a second transgression. Another distributary avulsed to the site ca. 2003, resulting in a second prograding delta lobe. Prior to flooding of Brown’s Cove, mafic-rich fluvial sediments from the southern part of the watershed were a...
JAWRA Journal of the American Water Resources Association, 2010
Journal of Environmental Engineering
Frontiers of Environmental Science Engineering in China, 2010
Water Air Soil Pollut, 1998
Hydrological Processes, Mar 18, 2007
Agu Fall Meeting Abstracts, Dec 1, 2006
Agu Fall Meeting Abstracts, Dec 1, 2007
Seasonal Snowcovers: Physics, Chemistry, Hydrology, 1987
Frontiers of Environmental Science & Engineering in China, 2009
JAWRA Journal of the American Water Resources Association, 2010
Journal of the American Water Resources Association, 2005
JAWRA Journal of the American Water Resources Association, 2014