17 Jun 2020

PUBLICATION NOTICE: Theory, Formulation, and Implementation of The Cartesian and Spherical Coordinate Two-Dimensional Depth-Averaged Module of the Adaptive Hydraulics (AdH) Finite Element Numerical Code

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, has undertaken the development of the multi-module Adaptive Hydraulics (AdH) hydrodynamic, sediment, water quality, and transport numerical code. This report documents the mathematical formulation and numerical implementation of the two-dimensional depth-averaged module of AdH.

17 Jun 2020

PUBLICATION NOTICE: Sediment Sorting by Hopper Dredging and Pump-Out Operations: Conceptual Model and Literature Review

Abstract: Dredged sediment placed on beaches or nearshore environments is customarily evaluated for compatibility with the native beach sediment to avoid unintended impacts to economic, environmental, or recreational resources. Consequently, some state regulatory authorities establish limits upon the fine-grained content for sediment designated for placement on certain beaches and nearshore environments. Hopper dredging operations for beach and nearshore placement typically include periods of overflow, which is recognized to produce some degree of separation between the size fractions of the dredged sediment. The degree of separation and the controlling factors of separation are presently poorly known and are the subject of this research. This report provides a conceptual model of the hopper dredging and placement processes, including the relevant processes associated with hopper dredge-associated sediment dynamics, generation and transport of the overflow sediment plume, and sediment winnowing at the beach outflow. Prior research is described, and knowledge gaps are identified. Finally, a research plan to validate prior research and to address knowledge gaps is presented. An annotated bibliography of relevant literature is given in an appendix. Documentation of the planned research presented herein will appear in future publications associated with this study.

10 Jun 2020

PUBLICATION NOTICE: Nearshore Placement Workshop 2019: Sediment Nourishment of the Nearshore Environment

Abstract: The Coastal Inlets Research Program and the Regional Sediment Management Program co-sponsored the 2019 Nearshore Placement Workshop. Thirty-four participants from the US Army Engineer Research and Development Center (ERDC) and numerous districts met in Vicksburg on January 29–30, 2019, as a part of the workshop. This workshop was convened to facilitate discussions on concerns districts face regarding nearshore placements from resource agencies and stakeholders, challenges to placing sediment in the nearshore, and future research needs. The workshop included ERDC presentations on the state of the science regarding nearshore placements; specific implementations of nearshore placements within various US Army Corps of Engineers districts; break-out-style discussions on nearshore placement challenges and potential paths forward; and group discussions on metrics for success, quantification of benefits, Statements of Need (SON), and research priorities. A few of the major recurring themes throughout the workshop were the importance of monitoring, concerns over the fate of fine-grained sediment, and difficulties conveying the benefits of nearshore placements to a wide range of audiences. The workshop culminated in a discussion of possible SON to be put forth to the ERDC research and development community. This special report describes the discussions and outcomes of the 2019 Nearshore Placement Workshop.

10 Jun 2020

PUBLICATION NOTICE: Projecting Changes in Food Security Throughout Central America

Abstract: Climate non-stationarity continues to change the productivity of local food and water supply. These changes in supplies could result in starvation or surpluses, greatly affecting the surrounding populations and causing adverse effects such as malnutrition, mass migration, and political unrest. This study addresses the following questions regarding the future potential of land resources to support local populations with food and water: How will crop production be affected by changing environmental conditions? Which specific regions are expected to experience the greatest pressure? How might we expect land use to shift through the end of the 21st century, based on future environmental conditions? Current crop growth is analyzed, along with projected crop growth based on future climate scenarios. Recent historic anthropogenic biome maps are statistically correlated with recent historic climate data to generate models and are applied to anticipated future climates to generate future anthrome maps. The crop analysis is then coupled with the anthromes results, yielding a crop suitability forecast. This analysis is constrained to the area of Central America over the course of the 21st century for this study.

10 Jun 2020

PUBLICATION NOTICE: Full-Scale Testing of Commercially Available Cementitious Backfill and Surface Capping Materials for Crater Repairs

Abstract: The Air Force Civil Engineer Center (AFCEC) Rapid Airfield Damage Recovery (RADR) program currently utilizes rapid-setting flowable fill (RSFF) and rapid-setting concrete (RSC) for backfilling and capping crater repairs. These materials have been proven successful through many full-scale tests, troop demonstrations, and live flight trafficking. However, only one proprietary product is currently approved for each material. Two candidate capping materials and one backfill material were evaluated by conducting simulated crater repairs and collecting appropriate data. For capping products, both small (8.5 ft x 8.5 ft) and large (15 ft x 15 ft) repairs were conducted and trafficked with simulated F-15E aircraft traffic. For the backfill material, three small repairs were backfilled and the California Bearing Ratio (CBR) was estimated at cure times of 0.5, 2, and 24 hr. Overall, repairs capped with Western Materials Fastrac 246 failed after only 2,000 passes, so the material is not currently recommended for approval. Repairs capped with Buzzi Unicem Ulti-Pave3® were able to sustain 3,500 passes before trafficking was ceased, so this material is recommended for approval as a crater repair capping material. CTS rapid-setting flowable fill backfill exhibited lower than expected CBR values and did not allow timely percolation of mix water, so it is not currently recommended for approval at this time.

10 Jun 2020

PUBLICATION NOTICE: Investigation of Materials for Charleroi Lock and Dam Monongahela River Reconstruction Project

Abstract: The investigation described in this report was conducted for the U.S. Army Engineer District, Pittsburgh as part of a preliminary investigation of cementitious materials and concrete design pursuant to construction of Charleroi Lock and Dam Monongahela River Reconstruction Project. Local materials provided to the U.S. Army Engineer Research Development Center (ERDC) for testing included three different coarse aggregate gradations, two fine aggregate sources, a type II (MH) cement, four fly ash sources, a slag cement, a silica fume, a limestone powder, five admixtures, and two water sources. Aggregate tests consisted of sieve analysis, specific gravity, absorption, materials finer than No. 200, organic impurities, soundness, LA abrasion, clay lumps and friable particles, flat and elongated particles, lightweight particles, and petrography. All cementitious, admixtures, and water-source materials were tested for chemical and physical properties based on appropriate specifications. In addition, four mixture proportions developed by the ERDC for this project in 2005 were scaled to determine the early stiffening of mortar, freezing and thawing, and heat of hydration. This report presents the material characteristic results determined by laboratory testing in accordance with American Society for Testing and Materials procedures or regulating specification criteria.

5 Jun 2020

Cold Regions Research and Engineering Laboratory announces closure of child development center

The Cold Regions Research and Engineering Laboratory (CRREL) announced June 5 that the child development center currently located at the laboratory in Hanover, New Hampshire, is scheduled to permanently close Sept. 15.

2 Jun 2020

PUBLICATION NOTICE: An Assessment of an Inexpensive COTS 360-degree Camera for Mapping and Localization in a GPS-denied Area

Purpose: The efficacy of using a low Size, Weight, Power, and Cost (SWAP-C) Commercial off the Shelf (COTS) 360-degree camera was evaluated for localization and positioning in a GPS-denied environment. Specifically, OpenVSLAM was utilized to generate point clouds with negligible drift using a RICOH THETA S 360-degree field of view camera without the aid of an Inertial Measurement Unit (IMU). OpenVSLAM is also demonstrated to show that it can localize and position with a pre-generated map.

2 Jun 2020

PUBLICATION NOTICE: Parallel File I/O for Geometric Models: Formats and Methods

Abstract: Processing large amounts of data in a High-Performance Computing (HPC) environment can be throttled quickly without an efficient method for utilizing disk I/O. The Geometry Engine component of the Virtual Environment for Sensor Performance Assessment (VESPA) uses MPI-IO to load the geometric data in parallel and avoid creating a bottleneck on disk I/O interactions. This parallel I/O method requires formatting the data into specific binary file formats so each MPI process of the parallel program can determine where to read or write data without colliding with other MPI processes. Addressing the collision problem resulted in the development of two binary file formats, the Mesh Binary file (.mb) and the Scene Chunk Pack file (.scp). The Mesh Binary file contains the essential data required to recreate the landscape and vegetation geometry used by the Geometry Engine. The Scene Chunk Pack file is used to write the partitioned geometry to disk, so the ray casting engine can reload the distributed geometry without repeating the partitioning process. Both of these files together support reading and writing for the partitioning phase and the ray casting phase of the Geometry Engine. This report discusses these formats in detail and outlines how the Geometry Engine reads and writes these files in parallel on HPC.

2 Jun 2020

PUBLICATION NOTICE: AIS Data: Real-Time Operation Support, Incident Investigations, and Waterway Use Analysis

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents examples of Automatic Identification System (AIS) data and capabilities used to support real-time operations, assist in incident investigations, and contribute to waterways usage analysis projects for a variety of infrastructure management needs across the US Army Corps of Engineers (USACE). These case study presentations serve as examples for those who are new to AIS technology or navigation infrastructure operations.