3 Jul 2025

Inner Harbor Navigation Canal Lock Replacement Study: Hydrodynamic Modeling and Ship Simulation

Abstract: The Inner Harbor Navigation Canal (IHNC) Lock connects the Mississippi River to the Gulf Intracoastal Waterway, surrounded by developed areas in New Orleans, Louisiana. Tow transit times through the current IHNC lock take up to 20 hours. The US Army Corps of Engineers, New Orleans District, has proposed constructing a new lock to reduce tow transit times significantly. However, the new lock will have potential effects on vehicle traffic patterns due to the three bridges across IHNC. To address potential navigation issues, hydrodynamic modeling and ship simulations of the study area were conducted for the three phases of the project: new lock construction, present lock deconstruction, and proposed new lock design. The hydrodynamic model was developed and validated to present conditions, simulating various water levels across the lock structure to provide water levels and currents for ship simulation. The ship simulation was used to record transit times to determine impacts of the waterborne vessel traffic on vehicular traffic due to bridge raising and lowering, as well as navigability of the bypass channels associated with lock construction and existing lock deconstruction. Elicitation from the towing industry was used to inform final design of the new IHNC lock and bypass channels.

2 Jul 2025

Remote Detection of Soil Shear Strength in Arctic and Subarctic Environments

Abstract: Soil shear strength affects many military activities and is affected significantly by plant roots. Unfortunately, root contribution to soil shear strength is difficult to measure and predict. In the boreal forest ecosystem, soil and hydrologic dynamics make soil shear strength less predictable, while the need for prediction grows due to the rapid changes occurring in this environment. Our current study objectives are to (1) observe possible aboveground vegetation indicators of soil shear strength variation across soils and other environmental heterogeneity, (2) observe possible image-based indicators of soil shear strength variation, and (3) identify the best remote-sensing data source for predicting soil shear strength variation. A total of 65 sites were sampled from a diversity of soil and vegetation types across interior Alaska and Ontario, Canada. Ground-collected data were analyzed to develop a predictive model, while a similar approach was undertaken with Sentinel-2 imagery. Results indicate that both ground-collected data and satellite imagery can reasonably predict boreal forest soil shear strength, with satellite imagery providing the higher predictive ability. A comparison of 10 m Sentinel-2 and submeter Maxar imagery indicated that Sentinel-2 provides a better prediction of soil shear strength.

1 Jul 2025

Bruce Goff and the Camp Parks Entrance Sign: Bruce Goff’s Life, Achievements, Design Philosophy, and Military Contributions at Camp Parks, California

The Camp Parks entrance sign in Camp Parks, California was recommended eligible by the Army for the National Register of Historic Places (NRHP) in 1998 under Criterion C and the California Office of Historic Preservation concurred with that decision in 1999. Designed by renowned architect Bruce Goff while stationed by the Navy at Camp Parks, the sign holds a significant value in the architectural industry, although the sign is no longer used for its initial purpose. All structures, especially historic ones, require regular planned maintenance and repair. The most notable cause of historic structure element failure or decay is not the fact that the historic structure is old, but rather, it is caused by incorrect or inappropriate repair or basic neglect of the historic building fabric. This document is a report detailing historic information regarding Camp Parks, the life and success of Goff, as well as the 3D scanning, and the subsequent relocation of the Camp Parks entrance sign. This report satisfies Section 110 of the National Historic Preservation Act (NHPA) of 1966 as amended and will aid in management of the sign by personnel at Fort Hunter Liggett and Camp Parks.

26 Jun 2025

Preliminary Study for Rapid Ground Stabilization

Abstract: The Army has a need to rapidly repair heavily damaged low-volume roads. This report describes the literature review, laboratory study, and preliminary technology evaluation for potential rapid road rehabilitation materials and equipment. The objective was to identify and evaluate equipment, materials, and techniques for rapid road repair. This phase of the study focuses on rapid stabilizers that, when added to native soil, could improve bearing capacity. Lightweight equipment and attachments were assessed for their ability to effectively excavate and place geomaterials. Several commercial soil stabilizers were identified that could meet strength requirements. Equipment attachments for a compact track loader were deemed most suitable for executing rapid repairs.

25 Jun 2025

Bioconcentration, Maternal Transfer, and Toxicokinetics of PFOS in a Multi-Generational Zebrafish Exposure

Abstract: To enable risk characterization of perfluorooctane sulfonic acid in extended chronic and multi-generational exposures, we assessed PFOS bioconcentration in zebrafish exposed continuously to environmentally-relevant PFOS concentrations through 180 days postfertilization in parental and first filial generation fish. Exposures included five replicate tanks per treatment where whole-body PFOS concentrations were measured. Perfluorooctane sulfonic acid accumulation reached an apparent steady state at ≤ 14 dpf where whole-body wet-weight concentrations remained constant through 180 dpf in the P and F1 generations. The median bioconcentration factor of 934 L/kg was observed for all PFOS exposures with a range from 255 to 2,136 L/kg which varied with PFOS exposure concentration and sex of adult fish. Maternal transfer of PFOS was observed from P females to F1 eggs where maternal whole-body and egg PFOS burdens were equivalent, suggesting PFOS transfer to eggs was not a depuration pathway. Finally, a toxicokinetic model was developed that reliably reproduced PFOS whole-body burdens across all exposure durations spanning the P and F1 generations, providing a tool for PFOS bioaccumulation predictions relevant for risk assessment of acute, chronic, and multi-generational exposures.

25 Jun 2025

Evaluating the Influence of Flexural Strength on Rigid Pavement Performance Under Simulated Aircraft Traffic

Abstract: A full-scale airfield pavement test section was constructed and trafficked by ERDC to investigate the impact of substandard flexural strength portland cement concrete on pavement structural support requirements under simulated aircraft loading conditions. The substandard pavements were representative of ones encountered in remote locations where there may be a lack of locally available competent materials, standard construction equipment, or a skilled labor force. The test section consisted of two PCC surface thicknesses constructed with a standard airfield flexural strength PCC mixture and a low flexural strength PCC mixture and a dowelled and non-dowelled joint. The test items were trafficked with a dual-wheel P-8 aircraft test gear mounted on a heavy-vehicle simulator. The outcomes of the tests showed a significant reduction in PCC pavement cracking performance resulting from the reduction in flexural strength. Instrumentation response data were analyzed to corroborate observed surface cracking. The field data were compared to DoD pavement design and evaluation procedures, and it found current procedures underpredicted observed performance in excess of 90 percent. These estimations may be overly conservative and may exceed a level of conservatism appropriate in a remote environment. The observed conservatism was attributed to simplifying assumptions and empirical correlations made in early development.

24 Jun 2025

A Field Sampling and Analysis Protocol for Assessing Occupational Exposure and Risk from Military Munition Storage Magazines

Abstract: An occupational health study was conducted inside reinforced-concrete earth-covered munitions storage magazines at Fort Wingate Depot Activity. HEPA vacuuming of bulk dust and wipe sample verification post-vacuuming was used. In Phase 1, no explosives detections exceeded site-specific screening criteria. In Phase 2, no exceedances were noted for detected explosives with criterion. Using structure/ reactivity characteristics within the explosives category, surrogates were assigned to the six explosives without occupational health screening criteria. Based upon structural similarities within the analysis category, assignments of surrogates to explosives without criteria did not adversely impact the conclusions. In Phase 1, lead was detected in bulk dust in all igloos, and all exceeded the applicable criterion for commercial/industrial workers. In Phase 2, all lead detections in wipe samples were below the wipe screening criteria. Results indicated the ECM interiors posed no unacceptable dermal occupational risk for explosives or lead residues following bulk dust removal. HEPA filter vacuuming of interior bulk dust in ECMs at FWDA reduced occupational risk/hazard for exposure via inhalation and dermal contact under worst-case exposure conditions. Both phases of sampling are widely applicable, provided the site-specific assumptions made for this study are evaluated for suitability to another specific application and adjusted if needed.

24 Jun 2025

Graphene-Coated Sand for Enhanced Water Reuse: Impact on Water Quality and Chemicals of Emerging Concern

Abstract: This paper investigates the potential of graphene-coated sand as an advanced filtration medium for improving water quality and mitigating chemicals of emerging concern in treated municipal wastewater, aiming to enhance water reuse. The study utilizes three types of sand coated with graphene to assess the impact of surface morphology, particle shape, and chemical composition on coating and filtration efficiency. Additionally, sand coated with graphene and activated graphene coated sand were both tested to understand the effect of coating and activation on the filtration process. The materials were characterized using digital microscopy, Raman spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. The material’s efficiency in removing turbidity, nutrients, chemical oxygen demand, bacteria, and specific CECs was studied. Our findings indicate that GCS significantly improves water quality parameters, with notable efficiency in removing turbidity, COD, and bacterial contaminants. The study also highlights the material’s capacity to remove challenging CECs like Sulfamethoxazole and Diphenhydramine, showcasing its potential as a sustainable solution for water reuse applications. This research contributes to the field by providing a comprehensive evaluation of GCS in water treatment, suggesting its potential for removing CECs from treated municipal wastewater.

24 Jun 2025

Analytical Solutions for Coupled Hydromechanical Modeling of Lateral Earth Pressures in Unsaturated Soils

Abstract: Lateral earth pressures in unsaturated soils undergo variations with changes in suction due to infiltration. The infiltration-induced alterations in the pressure head present a coupled hydromechanical problem, where interactions between solids and fluids influence the outcomes. However, existing analytical solutions for determining lateral earth pressures in unsaturated soils do not consider the effects of hydromechanical modeling. This paper presents analytical solutions for coupled hydromechanical modeling of lateral earth pressures in unsaturated soils. For this purpose, an analytical solution for coupled hydromechanical modeling of one-dimensional (vertical) infiltration is integrated into effective stress-based formulations for at-rest, active, and passive earth pressures of unsaturated soils. The solutions are presented for two cases: with and without a consequential drop in groundwater levels during infiltration. The results are verified by comparing them against those obtained from the finite difference method. The findings demonstrate significant differences between coupled and uncoupled results for pressure head and lateral earth pressures for fine-grained soils (characterized by small Gardner’s coefficients) and during transient (short time) conditions. The comparison of analytical and numerical results was very close for both cases and thus illustrates that the Laplace Transform is an accurate and robust method for determining analytical solutions for this problem.

18 Jun 2025

Evaluation of Commercial Cementitious Rapid-Setting Materials and Testing Protocol for Repairing Airfield Spalls

Abstract: The Pavement Repair Material Certification Program assists the US Air Force Civil Engineer Center by executing independent testing on select commercial cementitious proprietary products to repair partial-depth spalls in airfield concrete pavements. The selection of cementitious rapid-setting repair products can be difficult for military personnel considering the number of commercially available proprietary products. Too often, many product manufacturers highlight product strengths while masking undesirable properties. The purpose of this research was to evaluate selected commercially manufactured cementitious products through a series of laboratory testing protocols. These protocols were established to aid airfield managers and repair teams in selecting optimal airfield pavement spall repair materials by maintaining a database of approved products. Under the program, approximately four to six repair products are tested annually. This report presents the laboratory test methods and results of cementitious rapid-setting repair products tested at the US Army Engineer Research and Development Center from 2018 to 2022. The report also evaluates the overall test methods for assessing a material’s suitability for airfield spall repairs. Using the laboratory evaluation, eight products were identified as compatible for partial-depth airfield pavement concrete spall repairs.