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.

16 Dec 2025

Procedures for Obtaining US Air Force Global Air-Land Weather Exploitation Model (GALWEM) Data for Hydrological Modeling Applications: An Overview of the GALWEM Acquisition System (GAS) v1.0 and v2.0

Abstract: The Global Air Land Weather Exploitation Model (GALWEM) Acquisition System (GAS) is a software platform that serves to automate and simplify the procurement of numerical weather prediction model data from the 557th Weather Squadron. GAS allows for the download of meteorological and other environmental parameters from the GALWEM, an operational Numerical Weather Prediction capability operated by the 557th Weather Squadron for use by both Air Force and Army interests. GAS provides the ability to archive GALWEM data so that it may be used by the US Army Engineer Research and Development Center (ERDC) and other researchers. The report describes multiple methodologies for data access as well as suggestions for future work to improve computational efficiency and customer access.

8 Dec 2025

Improved Prediction of Soil Thermal Properties Using Gated Recurrent Unit Neural Networks

Abstract: Frost actions, such as frost depth penetration and thaw weakening, are damaging to airfields and roadways in cold regions. Machine learning techniques, such as recurrent neural networks, have been applied to this problem, but with a large focus on long short term memory (LSTM) neurons. Gated recurrent units (GRUs) are similar to LSTM neurons in terms of accuracy, but are more computationally efficient, and have yet to be applied to predicting soil thermal properties. Using a hyperparameter search, an optimal architecture for a recurrent neural network based on gated recurrent units was identified. A general model using temperature, thermal conductivity, and volumetric moisture content was found to predict temperatures effectively, having an error of less than 0.25°F across all depths. For predicting thermal conductivity, a model including temperature but not moisture content was found to be effective. For moisture content, the results were inconclusive as both models were affected by similar errors. Overall, the GRU-base recurrent neural networks were found to work well for predicting soil thermal properties in high-plasticity clays, and it is recommended to further expand the training datasets to include other frost-affected soil types.

24 Nov 2025

Ice Demolition Techniques—Rapid Improved Ribbon Bridge Placement and Enemy Forces Denial: Using Traditional Military Explosives Under Ice

Abstract: As the United States military focuses on furthering their lethality across cold regions, developing new techniques for equipment usage is necessary. On 19 March 2025, the US Army Engineer Research and Development Center–Cold Regions Research and Engineering Laboratory (ERDC-CRREL) collaborated with the Army Engineers from the 50th Multi-Role Bridge Company (MRBC), 6th Brigade Engineer Battalion (BEB), and Sapper Leader Course (SLC) to determine whether explosives can be used for Improved Ribbon Bridge (IRB) placement in ice-laden environments. As the US Army adapts to meet the evolving threats from foreign adversaries, there is an increased tactical necessity for enhanced bridging capabilities in frozen terrain. Developing an expedient method of removing ice from these waterways and placing IRBs for easy crossing of heavy military equipment is essential. Through this experiment it was determined that the use of a 40 lb cratering charge primed with M152 boosters significantly fractures the ice cover expeditiously. However, the ice expulsion rate found in this experiment was insufficient for IRB deployment which requires 60% expulsion rate. Although the experiment fell short of IRB requirements, it proved to be an efficient and effective countermobility tool for units who use frozen water ways as avenues of approach.