19 Sep 2025

Bridging the Impact Response of Polymers from the Nanoscale to the Macroscale

Abstract: Impact from a fast-moving object is a common event, but it can vary greatly in terms of scale, speed, and energy depending on the specific case. Recently, it has been suggested that scaling analysis can be used to relate the impact performance of materials at the nano- and microscale to their behavior at the macroscale, which is relevant for most applications. In this study, we explore the broad applicability of this approach by conducting micro- and macroprojectile impact tests on polymethyl methacrylate and polycarbonate films. By applying Buckingham 𝛱 dimensional analysis to all the impact test results, we demonstrate that the minimum perforation velocity is directly related to the geometric and material properties of each system across a broad range of size and energy scales. Interestingly, we find that the failure stress of the polymer, a critical material property that defines perforation resistance, can be empirically determined based on the deformation of the specific impact test.

19 Sep 2025

Design and Development of Large Format Additive Manufacturing Techniques

Abstract: This report discusses the creation of a large format additive manufacturing (LFAM) printer and initial test printing with the machine. A pellet-extruder head was attached to a computer numerical control (CNC) gantry. The team at the US Army Research and Development Center (ERDC) modified gantry arms to increase build height and designed electronic controls to allow for control of the printhead and the heated print bed. This report also covers print parameter optimization and print settings development.

19 Sep 2025

Natural and Nature-Based Features (NNBF) Design Process

Purpose: The US Army Corps of Engineers (USACE) provides water resource and river engineering technical support to a wide-ranging portfolio of projects across the country and world. To maintain state-of-the-art river engineering practice, research and development focused on updating conventional river engineering technologies and approaches is required. Incorporating Natural and Nature-Based Features (NNBF) and Natural Infrastructure (NI) strategies into the design of stable channels is one way to update river engineering practices (USACE 2017). The objective of this technical note is to provide a standard approach for incorporating NNBF-NI into the design of stable channels. Specific analysis and design details referred to herein are part of the NNBF Stabilization and Restoration (NNBF-SR) research and development (R&D) effort.

18 Sep 2025

Standard Operating Procedures for the Design, Construction, and Maintenance of Summer Roads and Trails, Drop Zones, and Firebreaks in Cold Regions

Abstact: As DoD investments across Alaska increase in response to DoD Arctic strategies, expanded training opportunities are necessary to enable the military to enhance their Arctic capabilities. In addition, wildfire management is increasingly important in the area as the summer season has expanded and warmed in recent decades. This report addresses the siting, design, construction, and maintenance of summer roads and trails, drop zones, and firebreaks on DoD lands in Alaska and other cold regions. It considers the harsh weather conditions, extreme seasonality, and remoteness of these environments, in addition to the general requirements of understanding the local environment, relevant risks, permitting, and regulations. The three types of linear infrastructure are assessed together as each involves the clearing of land and maintaining it as cleared, and therefore share common risks. This report summarizes best practices throughout the project lifecycle and synthesizes risk mitigation strategies informed by a comprehensive literature review and conversations with local training land managers. Using Fort Wainwright in Interior Alaska as an example, it provides Standard Operating Procedures (SOPs) to aid land managers and military unit leadership as they navigate challenges and opportunities in their increased use of these critical linear infrastructure types in high latitude environments.

17 Sep 2025

Validating Predicted Soil Boundaries with In Situ Collections

Abstract: This US Army Engineer Research and Development Center (ERDC) technical note describes the process used by the Intelligent Environmental Battlefield Awareness (IEBA) team to validate the spatial distribution and texture class attribution of soil boundary predictions. The predicted global soil boundary polygons will serve as a primary base layer for populating other environmental variables; thus, it is essential to assess their robustness prior to the attribution stage.

17 Sep 2025

Spring House, 666 Front Street, Lahaina, Hawaiʻi: Historic American Buildings Surveys HI-676

Abstract: The US Congress codified the National Historic Preservation Act of 1966 (NHPA), the nation’s most effective cultural resources legislation to date, mostly through establishing the National Register of Historic Places (NRHP). The NHPA requires federal agencies to address their cultural resources, which are defined as any prehistoric or historic district, site, building, structure, or object. Section 110 of the NHPA requires federal agencies to inventory and evaluate their cultural resources, and Section 106 requires them to determine the effect of federal undertakings on those potentially eligible for the NRHP. Lahaina is located in the western part of Maui County, in Hawaiʻi. The Spring House, erected circa 1823, is currently scheduled for demolition due to its major fire damages. This report documents the building to the standards of the Historic American Buildings Survey and includes a historic context, architectural descriptions, photographs, and measured drawings. This report satisfies Sections 106 and 110 of the National Historic Preservation Act of 1966 as amended and will be used by FEMA to document the building before its demolition.

17 Sep 2025

Vehicle Barrier Application for Soft Asset Protection at US Army Corps of Engineers (USACE) Dam Facilities

Abstract: The US Army Corps of Engineers (USACE) operates recreational areas at more than 400 lakes and river projects in 43 states. The rise of vehicular ramming attacks, in addition to attacks from vehicle-borne improvised explosive devices (VBIEDs), necessitates physical security measures to protect soft assets at these facilities. Therefore, a comprehensive vehicle-control plan, which includes the appropriate placement of effective vehicle barriers, is important for dam owners and operators to maintain safety at their facilities. This guide consolidates requirements, standards, and the design basis for barriers from multiple sources to provide dam owners with a resource to better protect against vehicular threats.

16 Sep 2025

Quality Control for Waterway Networks: Processing Algorithm and GIS Toolbox

Purpose: This Coastal and Hydraulics Engineering technical note (CHETN) documents the development of a US centered Geographic Information System (GIS) representation of navigable waterways for research purposes, including connections with the US Army Corps of Engineers (USACE) National Channel Framework (NCF) reaches, depths, and international connections, and the “Quality Control for Waterway Networks” processing algorithm. The algorithm is an automated method to update a waterway network created by the Coastal and Hydraulics Laboratory (CHL). After a user introduces desired changes to an input line layer representing waterways, the algorithm outputs links and nodes’ shapefiles containing a fully connected network, with geometries and depths aligned with the NCF, and controls for topology and attributes quality. In addition, spatial joins assign attributes to network nodes from other various sources of data. The product of this work is a GIS waterway network, along with a Quality Assurance and Quality Control (QAQC) script incorporated via toolbox within an open-source GIS software to maintain the waterway network updated. The algorithm has the capacity to be adapted to other transportation network needs or GIS software packages.

16 Sep 2025

Review of Threatened and Endangered Plant Species Potentially Impacting US Army Corps of Engineers Mission Areas

Abstract: This special report summarizes federally threatened and endangered plant species that have most affected recent or ongoing US Army Corps of Engineers (USACE) projects in terms of dollars spent on research, management, and mitigation. We also assess which of these highest cost-associated species are most likely to benefit from further research and conservation efforts, with the goals of species recovery and delisting.

16 Sep 2025

Standard Operating Procedures for the Design, Maintenance, and Operation of Arctic and Subarctic Winter Roads

Abstract: Operations in cold regions require vehicular maneuvering across snowpacks or frozen surfaces. Winter roads and their route determination, construction, and monitoring are widely studied. This report analyzes historical and current literature on winter road construction and operations, reviews risk assessment techniques, examines the impact of uncertain weather on road reliability, and provides a standard operating procedure for design, maintenance, and use. Winter roads, snow roads, ice roads, and ice bridges enable seasonal access in Arctic and Subarctic regions. They allow cross-country maneuverability over terrain like wetlands and bogs, which are impassable in summer. These roads are critical for training, logistics, and construction in areas without all-season access. When combined with ice bridges they can provide near-unlimited travel. Effectiveness depends on proper planning, construction, and monitoring. Snow roads require controlled compaction for strength, while ice roads require sufficient ice thickness to support loads. Both rely on tools like visual inspections, ground-penetrating radar, and unmanned aerial systems to ensure safety. With extreme seasonal variability, adaptive strategies are essential. Shortened seasons and unpredictable freeze–thaw cycles demand modern technologies, predictive weather modeling, and improved reinforcement. This report integrates historical knowledge with engineering advancements to improve winter road durability, reduce risks, and support cold-region operations.