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  • PUBLICATION NOTICE: Sediment Sorting by Hopper Dredging and Pump-Out Operations: Sampling Methods and Analysis

    Abstract: Hopper dredging operations for beach and nearshore placement typically include periods of overflow, which produces some degree of separation between the size fractions of the dredged sediment. The degree of separation and the controlling factors are presently poorly known. This report focuses on laboratory experiments aimed at determining (1) suitable sampling methods on a dredge, (2) composite sampling techniques to reduce analysis cost, (3) associated sampling intervals to achieve suitable sediment representation of a hopper load, and (4) a hydraulic means of sample splitting. Results showed that no statistical difference exists among the three methods used to sample the hopper weir overflow. The method used to sample deposited hopper sediment identified a bias in the percent fines that resulted from flow sheltering. Further, it was found that composited samples were able to quantify the concentration and percent fines accurately, although an analytical data experiment showed that the accuracy of a composited sample is dependent on the sampling intervals. The accuracy of the fines and concentration from a hydraulic sample splitter was found to be dependent on median grain size, with fine sediment being evenly distributed and coarser sediment increasing the error in concentration and grain size distribution.

  • Statement on barges/676 Bridge

    On the afternoon of August 4th, high flows along the Schuylkill River dislodged the Crane Barge LEHIGH and two associated hopper barges from their moorings. The barges, which were secured between the Spring Garden Bridge and the Vine Street Expressway/676 Bridge, were pushed up against the Vine Street Expressway/676 Bridge. The Pennsylvania Department of Transportation (PennDOT) closed the bridge to traffic in both directions. The U.S. Army Corps of Engineers and its contractor Atlantic Subsea, Inc. assessed the situation and worked on a plan to resolve the matter in coordination with the U.S. Coast Guard and the City of Philadelphia. When water levels subsided on Aug. 6, multiple tugboats were used to move the barges upriver just south of the Martin Luther King Jr. Bridge. The operation was successfully completed around noon on Aug. 6. PennDOT then reopened the bridge to vehicle traffic in the afternoon. The barges were being used as part of a project to dredge portions of the Schuylkill River above the Fairmount Dam.

  • Jacksonville District awards contract to repair Ponce de Leon North Jetty

    JACKSONVILLE, Fla. (Aug. 4, 2020) – The U.S. Army Corps of Engineers Jacksonville District awarded a $7,015,443 contract July 28, 2020, to Kiewit Infrastructure South Co. of Omaha, Neb., for the Ponce De Leon Inlet North Jetty Rehabilitation and Aid to Navigation Replacement Project at Ponce de Leon Inlet in Volusia County, Fla.

  • Army Corps awards contract for Absecon Island beach nourishment

    The U.S. Army Corps of Engineers’ Philadelphia District awarded a contract to Great Lakes Dredge & Dock Company of Oak Brook, Illinois for $23.8 million to complete periodic nourishment of the Absecon Island Coastal Storm Risk Management project in Atlantic County, N.J. The contract calls for placing approximately two million cubic yards of sand onto the beach in Atlantic City, Ventnor City, Margate City, and the borough of Longport.   

  • PUBLICATION NOTICE: Erosion Thresholds and Rates for Sand-Mud Mixtures

    Abstract: Differences in erosion behavior of non-cohesive and cohesive sediments are widely recognized. In many natural environments, sand and mud are not completely separated and occur as mixtures. Significantly less research has been conducted on the erosion behavior of sand-mud mixtures compared to the separate treatment of sand and mud erosion. Sedflume erosion experiments were conducted on sand-mud mixtures with varying mud content to define the relationships between mud content, critical stress for erosion (τc), and erosion rate. Sand-mud mixtures were prepared with three mud sources: (1) non-swelling clay (kaolinite), (2) swelling clay (kaolinite/bentonite), and (3) a swelling, natural mud from the Mississippi River. Test results showed that critical shear stresses of the mixed sediments departed from that of pure sand with mud fractions on the order of 2% to 10%. Peak τc was observed between 30% to 40% mud content, with swelling muds achieving a ten-fold increase in τc while a five-fold increase in τc was measured for kaolinite. Additionally, this study demonstrated that the introduction of small amounts (≤5%) of mud to sand reduced erosion rates by a factor of 10 to 100. This observed abatement of erosion rate has implications for the use of dredged materials in civil and environmental engineering projects.

  • PUBLICATION NOTICE: Investigation of Shoaling in the Federal Navigation Channel, Waukegan Harbor, Illinois

    Abstract: Persistent and excessive shoaling occurs in the Outer Harbor and Approach Channel of the Waukegan Harbor, Illinois. This report describes a numerical modeling study performed for the US Army Corps of Engineers, Chicago District, to evaluate the existing harbor and 11 structural alternatives for three crest elevations. This report provides details of numerical modeling study, analysis of field data, and estimates of shoaling. The focus of the study is the investigation of a variety of structural solutions intercepting and/or diverting sediments to reduce shoaling in the navigation channel. These include breakwaters, groins, spurs, and structural extensions with varying length and crest elevation connecting to the north beach and existing north breakwater. Estimates of both shoaling volume and height are developed with and without project using an integrated wave-flow-sediment transport numerical modeling approach. Quantitative reduction estimates are provided for each structural alternative investigated.

  • Corps awards beach restoration contract for St. Johns County Coastal Storm Risk Management Project

    The Jacksonville District, U.S. Army Corps of Engineers awarded a $15,179,050 contract July 7, 2020, to Great Lakes Dredge & Dock Company, LLC, of Oak Brook, Ill., to restore critically eroded shoreline along the coast of St. Johns County, Florida. The Coastal Storm Risk Management Project will include both dune and beach berm construction along approximately 2.6 miles of the St. Johns County coastline from Vilano Beach to South Ponte Vedra Beach. The initial construction will include placement of approximately 1.3 million cubic yards of sand that will be dredged from shoals located within St. Augustine Inlet. Future periodic nourishment events are planned at multi-year intervals.

  • U.S. Army Corps of Engineers awards contract to dredge Maumee Bay

    The U.S. Army Corps of Engineers, Buffalo District has awarded a $2.1 million contract to Ryba Marine and Construction to conduct dredging of the federal navigation channel in Maumee Bay, located along Lake Erie in Toledo Harbor, in the City of Toledo, Lucas County, Ohio.

  • Corps completes Dredged Material Management Plan for the Bull’s Island and Milliken Creek area

    The U.S. Army Corps of Engineers, Rock Island District has completed the Dredged Material Management Plan for the Bull’s Island and Milliken Creek dredge cuts on the Illinois Waterway.

  • Corps continues legacy of dredging at Port of Alaska

    All summer long, a crimson and white boat moves back and forth through the waters near the Port of Alaska collecting silt, sand and gravel off the seafloor to allow vessels to navigate the harbor in Anchorage. The boat is a dredging vessel called the Westport, operated by Manson Construction of Seattle, Wash., which the U.S. Army Corps of Engineers – Alaska District contracted to maintain the mooring areas for the past three years.