Emsworth Dam Scour 3D Model
USACE multibeam/Sidescan Sonar, Seabed Classification, IENC Mapping; Ohio, Allegheny and Monongahela Rivers PA, OH, WV
Project Owner - USACE Pittsburgh District
Project Classification - Navigation & Dredging Support Surveys, 100% Minimum Survey Coverage Density for Items 1, 3 & 4, and 200% Minimum Survey Coverage Density (50% overlap) for Items 2 & 5
SCOPE OF WORK:
Item 1, consisted of IENC feature collection and chart validation of 14 miles of the Allegheny River. The hydrographic multibeam survey covered 7 miles of Allegheny and 11 miles of the Monongahela river. Item 2, required multibeam surveys below the dam and manual cross sections with RTK from a work flat of the dam apron and out to ±10 depth. Item 3, multibeam surveys at Emsworth, Dashields, Montgomery, Pike Island, New Cumberland and Hannibal Locks and Dams, Ohio River; at Braddock, Lock 3, Charleroi, Maxwell, Grays Landing, Point Marion, Morgantown, Hildebrand, and Opekiska Locks and Dams Monongahela River and Lock & Dam 2 Allegheny River. These Locks & Dams are spread out over 250 miles of the Ohio, Monongahela and the Allegheny Rivers. The survey limits were from downstream Arrival Point to upstream Arrival Point including lock chambers and above and below dams. Item 4, The Multibeam Dam Scour surveys were performed at Emsworth, Dashields and Montgomery Locks and Dams. The coverage requirement for the multibeam surveys was 200% (50% overlap). The locks and dams were drawn in 3D and georeferenced from construction/as-built plans provided by Pittsburgh District. 3D models were produced incorporating the multibeam data and the Lock and Dam data as a scour analysis tool for Pittsburgh District Engineers. Item 5, The Multibeam / Sidescan survey of 55 miles of the Ohio River started at the point (mile 0.0) and ended at New Cumberland Locks and Dam (mile 55). The average width of the Ohio River was 1,600 feet and average depth was 20 feet. Sidescan data was collected simultaneously with the RESON 8124. RTK and the water surface were used as the project vertical datum. Gauge readings were taken hourly at upstream and downstream Locks and Dams and pool surface elevations were interpolated for data processing.
Position and heading for the survey was obtained using a Trimble Navigation MS860II dual frequency, dual antenna GPS receiver on-board the survey vessel. Trimble Navbeacon XL receiver provided U.S. Coast Guard Beacon DGPS correction for portions of the pool surveys. All Lock & Dam surveys were performed using RTK GPS positioning. Geodetic Control at each site was used for RTK GPS reference stations. SEAS Moving Asset Collection System (SMACS) was used for IENC feature collection. Multi-beam surveys were performed using a RESON SeaBat 8124 Multi-beam System with a TSS DMS-10 motion reference unit providing attitude correction. A RESON SVP14 was used to accurately measure and create sound velocity profiles.
DATA PROCESSING & DELIVERABLES:
Data processing software: MicroStation, AutoCAD, ArcView, Quester Tangent Multiview and HYPACK/HYSWEEP. AutoCAD and ArcView were used to create the final product in shape file with IENC S-57 attributes. HYPACK/HYSWEEP 2008 for hydrographic data collection and data processing. MicroStation V8 used to produce 50 scale planview drawings with Lock & Dam features, hydrographic depth data, 1 foot contours, 9 foot depth contour, and project pool shoreline. Microstation Inroads was used to produce DTM files. The planviews were delivered in shape file and MicroStation V8 format. Quester Tangent Multiview was used to process the multibeam sidescan backscatter and create GIS maps of seafloor substrate.