22 Jan 2026

Exopolysaccharides from Rhizobium Tropici Modified the Surface Characteristics of a Mississippi River Levee Soil Clay and its Bulk Soil Properties

Abstract: Global climate change has led to the increased frequency of extreme flooding events and heightened the vulnerability of river levees to flood related damage. One promising approach to enhancing the sustainability of levee stabilization is the use of eco-friendly, biologically produced soil additives as alternatives to conventional materials for erosion control. This study investigates the effects of exopolysaccharides (EPS) produced by Rhizobium tropici on the physical and engineering properties of clayey soil from a Mississippi River levee. Specifically, the study examines how EPS affects particle size, surface charge, surface area, and key bulk soil properties, including Atterberg limits, compaction behavior, and hydraulic conductivity. Soil samples were collected from a levee embankment located in south of Vidalia LA, an area historically prone to slough slides due to highly plastic nature of its floodplain clay soils. X-ray Power Diffraction was used to characterize the mineralogy of soil clay, EPS and EPS-clay composites. Particle size distribution and Zeta potentials measurements were performed on EPS and EPS-amended clays. Engineering test included Atterberg limit determinations (liquid and plastic limits) and standard compaction tests. The addition of EPS significantly increased the aggregate particle sizes of the levee clay through formation of EPS-clay composites. A strong correlation was observed between mean particle sizes and zeta potential in the composites. EPS also increased the liquid limit and plasticity of the soil while significantly reducing its hydraulic conductivity. Overall, EPS-amended soil demonstrated improved resistance to seepage and erosion, indicating that EPS has the potential to enhance levee soil stability and contribute to more sustainable flood control infrastructure.

21 Jan 2026

Development of Tidal and Surge Forcing in Boussinesq Wave Model FUNWAVE-TVD

PURPOSE: This Coastal and Hydraulics Engineering Technical Note (CHETN) documents the development of the tidal and surge-forcing module in the Boussinesq wave model FUNWAVE–Total Variation Diminishing (TVD) for wind-wave simulations, subjected to large-scale boundary forcing conditions. In a series of recent projects undertaken by the Coastal Hydraulics Laboratory (CHL) of the US Army Engineer Research and Development Center (ERDC), there was a need to model wind waves under time-varying boundary conditions due to tides, storm surges, or strong background flows. The implications on wave runup and overtopping (flooding) around inlets, due to the interaction of tide or surge-driven flows and waves (wave-current interactions), make the need for the development of surge and tide forcing vital to modeling waves with a Boussinesq-type model like FUNWAVE-TVD. Furthermore, strong velocity flows (currents) are not only responsible for depth-limited wave transformation and breaking at inlets but also directly influence sediment transport. Most phase-resolving wave models cannot facilitate these kinds of simulations because the wavemaker cannot generate the phase-resolving wave conditions and low-frequency motions (e.g., tides) at the same time. For example, in FUNWAVE-TVD, the combination of an internal wavemaker and a sponge layer is used to generate wind waves in the shoreward direction while absorbing waves with the sponge layer in the seaward direction behind the wavemaker. However, this type of combined system of wave generation and absorption cannot readily incorporate the external low-frequency forcing into wave generation.

21 Jan 2026

Supporting Urban Sustainability Through Resilient Rail Transit Systems

Abstract: Urban rail transit is vital to supporting urban sustainability across environmental, economic, and social pillars. However, recent extreme weather events, particular flooding, have increasingly disrupted its operations, high-lighting the urgent need to strengthen system resilience. Developing comprehensive resilience assessment methods with results of practical relevance is essential for evaluating the system’s capacity to withstand and recover from such disruptions, using quantifiable impacts across physical, operational, social, and economic dimensions. While resilience and sustainability are often discussed together in the context of climate change, methodologies for integrating sustainability considerations into resilience assessments to develop informed adaptation strategies remain underdeveloped. Drawing on the UN Sustainable Development Goals, this commentary examines the relationship between resilience and sustainability in the urban rail transit sector under disruptions related to natural disasters and climate change. Following this, it proposes a three-tier network modelling roadmap for assessing the resilience of urban rail transit, illustrating how sustainability concerns can be incorporated into resilience planning. This roadmap progresses from current mainstream topology-based approaches to a state-of-the-art performance-oriented method, and ultimately to a forward-looking vision that integrates socio-demographic considerations and prioritises equity. Positioned at the infrastructure-disaster- society nexus, this commentary advocates embedding a systemic view in transport network modelling to yield actionable resilience strategies that address extreme weather events while promoting urban sustainability.

14 Jan 2026

Fiscal Year 24 Sustainable Design and Development Support Order: Identifying Building Electrification and Decarbonization Opportunities for Army Leadership in Energy and Environmental Design (LEED) Projects

Abstract: In fiscal year 2024, the Army advanced its strategic goals for resilient and sustainable building design, certifying 12 new Leadership in Energy and Environmental Design (LEED) projects and reaching a total of 899 LEED-certified projects since 2006. Key findings of this report reflect the Army’s alignment with updated LEED prerequisites, including increased energy performance standards and new green-house gas emissions metrics. The ongoing challenges in decarbonization and electrification, including increased construction costs and maintenance uncertainties, underscore the need for early integrative planning and improved data collection. The report highlights the best practices and technology solutions that are critical for reducing carbon footprints and enhancing operational resilience for the purpose of closing implementation gaps in complying with new policy, such as the Department of the Army Policy Guidance on Resilient Buildings released 27 March 2024 and the 29 March 2023 DoD memorandum on Electrification of Standard Building Operations. The report also emphasizes the importance of early LEED documentation to improve certification outcomes. With the upcoming LEED v5 release and evolving Army policies, this year’s progress sets a strong foundation for further implementation of electrification and sustainability efforts in alignment with Army resiliency goals.

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.

13 Jan 2026

Wave Information Study ERA5 Wind-Field Evaluation

Abstract: The Wave Information Study (WIS) provides continuous wave hindcasts along US coastlines, including the Great Lakes and US Territories. As wave modeling and wind-field technologies have advanced, WIS is now positioned to transition to the new long-term archived hindcast wind fields available from ERA5, the fifth-generation global atmospheric reanalysis from the European Centre for Medium-Range Weather Forecasts. Before adopting ERA5 operationally within the WIS hindcast, formal testing compared ERA5 wind-forced hindcasts to the existing WIS hindcasts using Nation Center for Atmospheric Research Reanalysis 1 (NCAR-R1) winds. Results were validated against collocated and concurrent point-source and altimeter-based wave measurements from 2015 to 2018. ERA5 showed a 53% improvement in significant wave-height bias in the Atlantic and 76%–77% improvements in the Pacific. While improvements in average wave period were less consistent, ERA5 still showed better correlation across all domains. Hawaii showed modest improvements, except for bias. ERA5 also outperformed NCAR-R1 in mean wave direction at peak frequency, with bias reductions of 5%–72%, most notably in Hawaii, where wave modeling is typically challenging. Overall, it was concluded that the ERA5 forced WIS estimates were more accurate than the NCAR forced WIS estimates, supporting the operational transition of WIS to ERA5.

13 Jan 2026

Major Freight Corridors in the US: Mapping of Commodity Flows on Waterborne, Rail, and Truck Networks

Abstract: Within the context of complex, interconnected, multimodal transportation, the US Army Corps of Engineers (USACE) provides safe, reliable, efficient, effective, and environmentally sustainable waterborne transportation systems for the movement of commerce, national security needs, and recreation. Understanding the role of waterways within the multimodal transportation system would allow for comprehensive resource allocation, including dredging prioritization. In 2022, approximately 19,810 million tons of goods were transported within, to, and from the US, with truck being the dominant mode for the domestic portion of the trip (64 percent). Relatively recent legislation calls for a multimodal representation of freight, one that facilitates transportation planning and asset management. However, traditional data collection and analysis has focused on single modes, preventing nationwide, multimodal representations of commodity flows. This report presents major commodity corridors within, to, and from the US by combining diverse sources and homogenizing data dimensions. The resulting information and commodity-specific maps help to contextualize waterborne navigation’s role within the broader multimodal transportation system. A key finding from the study indicates that the mouth of the Mississippi River in Louisiana carried in 2019 more volume of freight annually than any other waterway, railroad, or highway segment in the US.

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.

9 Jan 2026

Design of River Training Structures Using Isogeomorphic Constraints

Abstract: Prepared for the Mississippi River Geomorphology and Potamology program of the United States Army Corps of Engineers (USACE), through the Coastal and Hydraulics Laboratory (CHL), this report introduces the concept of river control structure design using isogeomorphic constraints. The report defines isogeomorphic design methodology and demonstrates the application of the methodology using both analytic and numerical examples. The examples investigated herein are idealized, and application to real-world conditions (such as a dike-field) would be far more complex than what is demonstrated herein. This report merely serves as an introduction to a novel design paradigm that future studies can further investigate and refine with the ultimate objective of developing improved design guidance for USACE.

7 Jan 2026

Evaluation of Seven Bridges at Fort Hunter Liggett, California, for Eligibility to the National Register of Historic Places

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 re-sources, 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. Fort Hunter Liggett is in central California, within Monterey County. It was first established as the Hunter Liggett Military Reservation in 1941. The post was renamed Fort Hunter Liggett in 1975. This report provides a determination of eligibility for the NRHP for seven properties (Bridges 749, 750, 753, 760, 767, 779, and 781) constructed between 1965 and 2010 and recommends that none are eligible under the NRHP and the California Register of Historic Resources (CRHR) criteria.