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https://hdl.handle.net/11681/7437| Title: | Monongahela Dam 4 Spillway, Pennsylvania : hydraulic model investigation |
| Authors: | United States. Army. Corps of Engineers. Pittsburgh District. Cooper, Deborah R. |
| Keywords: | Broad crested weir Energy dissipation Monongahela River Riprap Spillway Stilling basin Velocities Water-surface Hydraulic structures Dams |
| Publisher: | Coastal and Hydraulics Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
| Series/Report no.: | Technical report (U.S. Army Engineer Waterways Experiment Station) ; CHL-97-10. |
| Description: | Technical Report Partial Abstract: Monongahela Dam 4 is located on the Monogahela River 34.1 km (21.2 miles) upstream of the confluence of the Ohio, Allegheny, and Monogahela Rivers, in the city of Charleroi, PA. The existing dam maintains the navigation pool between the Dam 4 and Dam 5 locks and dams. Normal upper pool elevation for the Monogahela 4 is presently at el 743.5 (all elevations cited herein are in feet referred to the National Geodetic Vertical Datum). The existing spillway section of Dam 4 consists of a gated crest (el 724.0) located within the main channel of the waterway. Energy is dissipated on a horizontal apron with baffle blocks terminated by an end sill. The U.S. Army Engineer District, Pittsburgh, developed a "two-for-three" plan for renovating locks and dams on the lower Monogahela River that would save the cost of having to reconstruct L&D 3 and reduce transportation costs by eliminating bottlenecks caused by the small locks at L&D's 3 and 4 and by reducing one lockage cycle. The plan calls for building a new gated dam at the current L&D 2, eliminating L&D 3, and replacing the locks at L&D 4 with new, larger locks. The change would also mean Pool 2 would be raised by about 1.5 m (5 ft) and the current Pool 3 would be lowered by about 1.0 m (3.2 ft) (lowering the tailwater for L&D 4 by 1.0 m (3.2 ft)). The dam consists of a navigable gated structure with three radial tainter gates and two piggyback gates. The original derrick stone placed below the structure has experienced significant scour. The future lower tailwater may result in more severe scour unless the condition is remedied. |
| Rights: | Approved for public release; distribution is unlimited. |
| URI: | http://hdl.handle.net/11681/7437 |
| Appears in Collections: | Technical Report |
