26 Apr 2021

Houston Ship Channel Expansion Channel Improvement Project (ECIP) Numerical Modeling Report: Increased Channel Width Analysis

Abstract: The Houston Ship Channel is one of the busiest deep-draft navigation channels in the United States and must be able to accommodate larger vessel dimensions over time. The U.S. Army Engineer District, Galveston (SWG) requested the U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory perform hydrodynamic and sediment modeling of proposed modifications along the Houston Ship Channel. The modeling results are necessary to provide data for salinity and sediment transport analysis as well as ship simulation studies. SWG provided a project alternative that includes channel widening, deepening, and bend easing. After initial analysis, two additional channel widths in the bay portion of the Houston Ship Channel were requested for testing. The results of these additional channel widths are presented in this report. The model shows that the salinity does not vary significantly due to the channel modifications being considered for this project. Changes in salinity are 2 parts per thousand or less. The tidal prism increases by less than 2% when the project is included, and the tidal amplitudes increase by no more than 0.01 meter. The residual velocity vectors do vary in and around areas where project modifications are made.

26 Apr 2021

Automated Construction of Expeditionary Structures (ACES): Materials and Testing

Abstract: Complex military operations often result in U.S. forces remaining at deployed locations for long periods. In such cases, more sustainable facilities are required to better accommodate and protect forward-deployed forces. Current efforts to develop safer, more sustainable operating facilities for contingency bases involve construction activities that require a redesign of the types and characteristics of the structures constructed, that reduce the resources required to build, and that decrease the resources needed to operate and maintain the completed facilities. The Automated Construction of Expeditionary Structures (ACES) project was undertaken to develop the capability to “print” custom-designed expeditionary structures on demand, in the field, using locally available materials with the minimum number of personnel. This work investigated large-scale automated “additive construction” (i.e., 3D printing with concrete) for construction applications. This report, which documents ACES materials and testing, is one of four technical reports, each of which details a major area of the ACES research project, its research processes, and its associated results. There major areas include System Requirements, Construction, and Performance; Energy and Modeling; Materials and Testing; Architectural and Structural Analysis.

26 Apr 2021

altWIZ: A System for Satellite Radar Altimeter Evaluation of Modeled Wave Heights

Purpose: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the design and implementation of a wave model evaluation system, altWIZ, which uses wave height observations from operational satellite radar altimeters. The altWIZ system utilizes two recently released altimeter databases: Ribal and Young (2019) and European Space Agency Sea State Climate Change Initiative v.1.1 level 2 (Dodet et al. 2020). The system facilitates model evaluation against 1 Hz1 altimeter data or a product created by averaging altimeter data in space and time around model grid points. The system allows, for the first time, quantitative analysis of spatial model errors within the U.S. Army Corps of Engineers (USACE) Wave Information Study (WIS) 30+ year hindcast for coastal United States. The system is demonstrated on the WIS 2017 Atlantic hindcast, using a 1/2° basin scale grid and a 1/4° regional grid of the East Coast. Consistent spatial patterns of increased bias and root-mean-square-error are exposed. Seasonal strengthening and weakening of these spatial patterns are found, related to the seasonal variation of wave energy. Some model errors correspond to areas known for high currents, and thus wave-current interaction. In conjunction with the model comparison, additional functions for pairing altimeter measurements with buoy data and storm tracks have been built. Appendices give information on the code access (Appendix I), organization and files (Appendix II), example usage (Appendix III), and demonstrating options (Appendix IV).

23 Apr 2021

Virtual public meetings scheduled for Fort Peck Dam test flows draft environmental impact statement

OMAHA, Neb. - The U.S. Army Corps of Engineers, Omaha District will host virtual public meetings on Tuesday, May 4, and Thursday, May 6, from 6-8:30 p.m. CST, to gather input on the recently released draft Fort Peck Dam test flow environmental impact statement. The draft EIS assesses test flow capacity from Fort Peck Dam to promote growth and survival of pallid sturgeon during the free swimming, juvenile stage prior to their settling out into the headwaters of Lake Sakakawea.