23 Feb 2026

Ice Cutting and Removal for Cold Weather Improved Ribbon Bridge (IRB) Crossings

Frozen rivers provide an obstacle for any military force, as ice impedes the use of Improved Ribbon Bridges (IRBs) or other bridging vehicles. Finding an efficient way to cut and remove ice to allow for the emplacement of bridging assets is critical. The US Army Cold Regions Research and Engineering Laboratory’s (CRREL) Cold Weather IRB team went to Camp Grafton, North Dakota, to collect data for the North Dakota National Guard who were conducting a frozen wet gap crossing in February of 2022. Both quantitative and qualitative data were collected to evaluate strategies for ice cutting, removal, and IRB placement. After ice cutting and removal, an IRB bay was successfully placed in the frozen pond. Laboratory tests were conducted in March 2022 to examine different chainsaw chains for cutting an ice sheet grown in the Geophysical Research Facility (GRF) at CRREL. Chainsaws were determined to be an effective tool for cutting ice, and the speed and comfortability of different chains were documented. The data collected from this project will help to drive the North Dakota National Guard creation of a winter bridging course and will be used to update the Army’s Tactics Techniques and Procedures (TTPs) for cold weather bridging operations.

20 Feb 2026

Demonstration Validation of Industrial Supercritical Water Oxidation (iSCWO) PFAS Destruction Technology: Aqueous Film-Forming Foam Treatment by General Atomics (GA) iSCWO System

Abstract: The Department of Defense (DoD) is confronted with a pressing environmental challenge concerning legacy aqueous film-forming foam (AFFF) concentrate, historically used in firefighting activities. Legacy AFFF contains PFAS, which are identified as persistent environmental contaminants associated with adverse health effects. Considering increasing environmental regulations and concerns regarding human health impacts, the DoD needs to properly destroy legacy AFFF. The US Army Engineer Research and Development Center (ERDC) led a project focused on the demonstration and validation of technologies for the destruction of PFAS in AFFF. Results are presented for the treatment of 100 gal. of AFFF using the General Atomics industrial Supercritical Water Oxidation system. The demonstration showed destruction removal efficiencies (DREs) for total PFAS analyzed via total oxidizable precursor (TOP) assay (S24 PFAS), ranging from 98.5% to 99.9991%. No volatile fluorinated compounds were detected in the stack emissions as analyzed via Other Test Method 50; however, up to 6,000 ppt S51 PFAS as analyzed via TOP assay was detected in demister effluent. The energy consumed per cubic meter of AFFF and order of magnitude S24 PFAS destroyed ranged from 2 to 24 MWh, while the energy consumed per gram of S24 PFAS destroyed ranged from 0.046 to 48 MWh.

18 Feb 2026

Infection Risk Assessment for Socially Structured Population Using Stochastic Microexposure Model

Abstract: Predicting infection outbreak dynamics within local microenvironments is a challenging task. Some methods assume smaller population pools and often lack the statistical power of inferences. Others are designed for larger population pools and cannot be downscaled to accommodate the details of microenvironments. Practicable infection risk assessment models should account for population size, geometry and occupancy of public places, behavioral and professional patterns of daily routines, and societal structure. This study is based on the stochastic microexposure model, which has been generalized to describe clustered populations. The methodology is demonstrated for a community of several thousand students on campus. The results indicate the social structure has the first order effect on the spread of the infection. Depending on the number, size, and degree of inner- and outer-cluster connections, the outbreak exhibits distinct durations, power, and multiple peaks of infection. Moreover, the contribution of different microenvironments to infection risk evolves during the course of the outbreak. Social structure plays a major role in infection spread and should be accounted for in risk prediction tools. The stochastic microexposure model accounts for the social structure of a population at multiple scales and can predict the dynamic contributions of different microenvironments to infection spread risks.

9 Feb 2026

Ice-Resistant Breakwater Rock Sizing at Elim, Alaska

Abstract: The Elim Subsistence Harbor project requires breakwaters capable of withstanding wave action and sea ice forces in Norton Bay, Alaska. This study analyzed meteorological data, satellite imagery, and ice formation patterns to determine appropriate armor stone sizing based on ice forces for the proposed breakwaters. Analysis revealed that Elim experiences predominantly northerly winds during winter, with southwesterly components developing during the May–June breakup period. Offshore ice breakup occurs earlier at Elim (late March) than at Nome (late April). Using the Modified Stefan Equation calibrated with field measurements, end-of-season ice thickness near shore averages 1.4 m. Ice forces at Elim are expected to be less severe than at Nome because of wind patterns and directional constraints, with primary concerns limited to ice approaching from southwest directions during breakup. Using empirical evidence from Nome Harbor and physical model studies, we recommend a zoned armoring approach using 8-ton stone for toes and 4-ton stone on slopes in ice-exposed areas as minimum protection, or 8-ton stone throughout ice-exposed zones for enhanced durability. Relatively steep slopes (1.5H:1V to 2H:1V) should be maintained to encourage protective rubble ramp development during ice interactions.

5 Feb 2026

Evaluating Snow Pavement Strength in Remote Cold Environments via California Bearing Ratio (CBR) and Russian Snow Penetrometer (RSP) Combined Testing

Abstract: Accurate assessment of compacted snow strength is critical for ensuring the safety and performance of snow runways in cold environments. The Russian Snow Penetrometer (RSP) is widely used in snow science and engineering due to its simplicity, portability, and capability for rapid field measurements under extreme conditions. Conversely, the California Bearing Ratio (CBR) test remains the benchmark for evaluating the load-bearing capacity of conventional granular materials but is seldom applied to snow because of logistical constraints and the material’s complex mechanical behavior. The relationship between these two pavement evaluation tools remains poorly defined. This work investigates how RSP strength indices relate to CBR measurements to determine whether the RSP can serve as a practical proxy for snow pavement load-bearing capacity. Side-by-side field measurements of snow pavement strength were collected over a 30 h period at two test section locations. Both methods captured temporal strength increases and spatial variability, with consistently higher values at the second site attributed to extended sintering. A moderate linear correlation (R2 = 0.44) between RSP and CBR results supports a quantifiable relationship between the two methods. These findings begin to bridge the gap between conventional pavement testing and snow-specific strength evaluation, demonstrating the potential of the RSP for rapid assessment of snow runways. Continued data collection and analysis will refine this relationship and strengthen its applicability for operational use.

5 Feb 2026

Compressed Snow Blocks: Evaluating the Feasibility of Adapting Earth Block Technology for Cold Regions

Abstract: Snow construction plays a crucial role in military operations in cold regions, providing tactical fortifications, thermal insulation, and emergency infrastructure in environments where conventional building materials are scarce or require extensive infrastructure for support. Current snow construction methods, including manual piling and compaction, are labor-intensive and inconsistent, limiting their use in large-scale or time-sensitive operations. This study explores the feasibility of adapting a compressed earth block (CEB) machine to produce compressed snow blocks (CSBs) as modular, uniform building units for cold-region applications. Using an AECT Impact 2001A hydraulic press, naturally occurring snow was processed with a snowblower and compacted at maximum operating pressure (i.e., 20,684 kPa) to evaluate block formation, dimensional consistency, and density. The machine successfully produced relatively consistent CSBs, but the initial 3–4 blocks following block height adjustment were generally unsuccessful (e.g., incorrect block height or collapsed/broke) while the machine reached its steady state cyclic condition. These blocks were discarded and excluded from the dataset. The successful CSBs had mean block heights of 7.76 ± 0.56 cm and densities comparable to ice (i.e., 0.83 g/cm ³). Variations in block height and mass may be attributed to manual snow loading and minor material impurities. While the dataset is limited, the results warrant further investigation into this technology, particularly regarding CSB strength (i.e., hardness and compressive strength) and performance under variable snow and environmental conditions. Mechanized snow compaction using existing CEB technology is technically feasible and capable of producing uniform, structurally stable CSBs but requires further investigation and modifications to reach its full potential. With design improvements such as automated snow feeding, cold-resistant components, and system winterization, this approach could enable scalable CSB production for rapid, on-site construction of snow-based structures in Arctic environments, supporting the military and civilian needs.

28 Jan 2026

Unpiloted Aerial System–Borne Ground-Penetrating Radar for Snow Depth Estimation in Mountainous Warfighter Domain

Abstract: We demonstrate the latest capability in unpiloted aerial systems (UAS) ground-penetrating radar (GPR) measurements for snow depth estimation in mountainous terrain. Several technical considerations are important for successful data collections such as aircraft radio frequency link interference. We found that a 2.4 GHz ground control station to aircraft link frequency maintains independence from the 0−1.5 GHz bandwidth of the Zond Aero 500 GPR. Between flights at 2 m and 4 m above ground level (AGL), the footprint of the radar signal on the ground increases by approximately 25%, which increases off-nadir scattering and reduces reflection coherence. We developed an automated layer detection tool to identify air-snow and snow-soil interfaces within the radar signal and estimated snow depth using these automated signal interpretation methods and user-guided interpretations for validation. We found that flights conducted at 2 m AGL resulted in more precise snow depth estimates (21 cm [7%] uncertainty) than flights conducted at 4 m AGL (34 cm [12%] uncertainty). We estimated snow depth with UAS-GPR; however, with further development, this technique can inform near-real-time retrievals of additional snow properties critical to vehicle mobility within the warfighter domain.

14 Jan 2026

Field Demonstration of Magnesium Phosphate Concrete Pavement Repairs for Resilience to Heat and Petroleum, Oils, and Lubricants Exposure

Magnesium phosphate concrete (MPC) represents a possible alternative to portland cement concrete (PCC) that may be more resilient to unique types of distress created by aircraft operated by the United States Armed Forces. Aircraft such as the V-22 Osprey expose airfield pavement to petroleum, oils, and lubricants (POL) as well as surface temperatures up to 400°F. These conditions cause damage to the surface of concrete pavements, resulting in the exposure of aggregates, erosion of the surface, and the creation of foreign object debris. The US Army Engineer Research and Development Center (ERDC) has developed a nonproprietary MPC mixture, which in this study was refined and used to implement full and partial-depth repairs of a V-22 parking apron experiencing heat and POL damage at Cannon Air Force Base.

9 Jan 2026

Review of Hydroacoustic Data Associated with Small-Diameter Vinyl and Timber Pile Driving Operations

This review investigates root-mean-square sound levels, peak sound levels, and single-strike sound exposure levels resulting from small-diameter vinyl and timber pile driving operations with sufficient supporting information to assess potential impact on endangered species identified in the NOAA acoustic impact calculator. We identify 49 relevant records associated with installing timber pilings 14 in. in diameter and smaller and one record associated with vinyl piling. While acceptable for use as proxy data within the NOAA tool, the records exhibit significant unexplainable scatter of as much as +20 dB. Example calculations show that well intentioned hypothetical proposals coordinated in the permit application process could project vastly different impacts to endangered species. We therefore conclude that, within the framework of current practices and tools, these data cannot support informed decision-making by US Army Corps of Engineers (USACE) regulators as to whether small-scale timber or vinyl pile driving operations will jeopardize the continued existence of protected species or result in the destruction or adverse modification of critical habitat to comply with the Endangered Species Act. We recommend supplementing existing data with targeted collections as well as developing pile-specific coordination and assessment guidance for use by USACE regulators during the permitting process.

16 Dec 2025

Fiber-Optic Distributed Acoustic Sensing for Nondestructive Monitoring of Permafrost

Fiber-optic distributed acoustic sensing (DAS) has gained traction in recent years as a geophysical monitoring tool. Advancements in commercially available DAS have allowed for sub-10 m data resolution and high sampling rates (over 10 kHz), leading to the use of DAS for infrastructure change detection and localization monitoring. Using this technology, a team from the US Army Engineer Research and Development Center–Cold Regions Research and Engineering Laboratory (ERDC-CRREL) built a field campaign around monitoring changes in permafrost using DAS via a dispersion analysis of surface wave propagation. In May 2024, active seismic testing was performed on a rapidly deployed, surface-laid, nondestructive DAS array above CRREL’s permafrost tunnel. Active source testing was repeated in September 2024 to collect data that may indicate changes in the seismic response due to permafrost changes. DAS response data was also collected from an unmanned aerial system (UAS) to evaluate for potential use in standoff assessment of permafrost changes. The field campaign results indicate that nondestructive DAS arrays are likely useful in detecting and localizing changes in near-surface properties of the permafrost.