30 Sep 2025

EWN Compass: Implementation Toolbox for Natural and Nature-Based Features

Purpose: This Engineering With Nature® (EWN®) technical note introduces the EWN Compass: Implementation Toolbox for Natural and Nature-Based Features—a user-friendly, web-based application developed using Esri ArcGIS Online. Designed to support practitioners in selecting and integrating natural and nature-based features (NNBF) into infrastructure projects, the toolbox provides structured access to existing resources, case studies, and environmental data to inform resilient and sustainable design solutions.

29 Sep 2025

Understanding Hurdles to Expanded Beneficial Use of Dredged Sediment: Stakeholder Perspectives

Purpose: This technical note (TN) is the second in a series of investigative reports seeking pathways and opportunities to expand beneficial use (BU) of dredged material (DM). This TN summarizes the results of stakeholder outreach and feedback on perceptions about potential BU barriers to be overcome. The purpose of the study was to aid the US Army Corps of Engineers (USACE) dredging and DM management practices, specifically BU of DM (hereinafter BUDM), that USACE manages from various navigation channels and ports around the nation. Per the 28 January 2023 Chief of Engineers’ Command Philosophy Notice, USACE is aiming to achieve a goal of 70% BU by the year 2030 (HQUSACE 2023), hereinafter the Chief’s 70/30 goal.

29 Sep 2025

Physicochemical Kinetics of Rapid Soil Stabilization Using Calcium Sulfoaluminate-Based Cements

Abstract: Rapid stabilization of weak soil offers a promising option for quick infrastructure development and soil repair. The interaction between the rapid stabilizer and the soil is critical in defining its strength and durability. This study investigates the physicochemical effects of using Calcium Sulfoaluminate (CSA) cement-based stabilizers for rapid stabilization of weak clays, focusing on early age (<1 day) reaction kinetics and its effect on the short-term and long-term engineering characteristics. Geochemical modeling is proposed to model the chemical kinetics and predict the formation of strength-enhancing products in the stabilized soil mixtures. The study investigates the unconfined compression strength and durability (cyclic wetting and drying) of stabilized soil. Results showed stabilizers with a higher proportion (50 wt. percentage or more) of CSA (CSA-rich) achieved up to 80 % of the 28–day strength in 60 min after stabilization. Mineralogical characterization using X-Ray Diffraction, Thermogravimetric Analysis, and Scanning Electron Microscopy, identified Ettringite in CSA-rich stabilizers and Calcium-Silicate-Hydrates (C-S-H) in stabilizers with a higher (50 wt. percentage or more) proportion of Portland Cement (PC-rich) stabilizers as key strength-enhancing products. Integrating the modeling results with the engineering and mineralogical characterization provided valuable insights into the rapid stabilization mechanisms of CSA cement.

29 Sep 2025

Asset Condition and Probability of Failure Assessment–A Vision for Civil Works: A Document to Guide Collaboration and Innovation for the US Army Corps of Engineers Civil Works Asset Management System

Abstract: The US Army Corps of Engineers (USACE) is rapidly improving its asset management system through a variety of research projects and other work efforts that focus on how risk, condition, and probability of failure are conceived, communicated, and used for decision-making across the agency. As these projects move forward, it is critical that USACE defines a long-term vision for condition and probability of failure assessments across the entire asset management system. This Special Report defines that vision with the goal of achieving consensus and buy-in from a variety of participants that will need to buy-in to achieve success. An additional benefit to identifying an end vision for this work is to identify collaborative opportunities and any gaps that must be addressed to achieve it.

29 Sep 2025

State of Practice and Recommendations to Enhance Probability of Failure Estimates for Civil Works Infrastructure Components

Abstract: As the US Army Corps of Engineers (USACE) continues to improve its asset management system, it is imperative that maintenance investments across its wide infrastructure portfolio are maximizing risk reduction. A key component of risk is probability of failure. Presently, USACE estimates probability of failure for asset components in a variety of ways across business lines, activities, and decision spaces. This document explores the variations in the state of practice for probability of failure estimates across USACE and contrasts them with available best practices and methodologies. The review found several key gaps between the state of practice and best practices, including a lack of component failure and life data useful for time-to-failure parameter estimates, a lack of codified definitions of failure, no clear and consistent guidance for probability of failure estimates across business lines or decision spaces, and no methodologies that account for environmental variation at a facility. These gaps are addressed by a research strategy that compares and contrasts several probability of failure calculation methods using presently available data, identifies relevant life data for future collection, and defines a framework for investing in improved probability of failure assessments at facilities.

29 Sep 2025

Planning-Level Wetland Delineation of Fee-Owned and Trust-Held Properties of the Little Traverse Bay Band of Odawa Indians

Abstract: A planning-level wetland delineation is an important visualization tool for identifying the location and type of wetlands on the landscape, prioritizing areas for conservation and restoration practices, performing alternative analysis, and informing design and development of infrastructure needs. This study used a combination of off-site data analysis and field data collection to identify the location and extent of wetlands on 1,428 acres of fee-owned and trust-held properties of the Little Traverse Bay Band of Odawa Indians (LTBB). The study found that a wide variety of wetlands occur across approximately 313.6 acres, including 65 acres of wetland-nonwetland mosaic features. These wetlands benefit local communities by providing flood risk reduction, habitat for a wide array of species, and improved water quality. Opportunities to increase wetland functions through management activities, including restoration, were identified. This wetland delineation was conducted under the Planning Assistance to States Program, which provides technical assistance to states, tribal communities, and local governments and was administered via an agreement between the US Army Corps of Engineers–Detroit District and the LTBB. This approach has the potential to provide similar information to other tribal groups interested in identifying and delineating wetlands to improve the management of valuable natural resources.

29 Sep 2025

River Training Structure Design Study for Stabilization at Bonanza Bar

Abstract: The Huntington District (LRH) has repeatedly dredged within the navigation channel at Ohio River Mile (RM) 353, adjacent to a location known as Bonanza Bar. An in-channel bar has developed from the placement of the dredged material along the left-descending bank where a bar was historically present. Recently, the frequency of dredging in this area has decreased, suggesting that the presence of the bar is providing some degree of channel constriction. LRH approached the US Army Engineer Research and Development Center to model possible river training structures to provide channel constriction and stabilize the placement of dredged material at Bonanza Bar. A two-dimensional hydraulic numerical model was developed to test structural alternatives by estimating the impacts on the velocities within the main channel, along the length of the bar, and along the mussel habitat within the side channel. Various rock dikes with bank protection were modeled and general design guidance and modeling results are presented. Modeling results indicate increases in main channel velocities and decreases in flow behind the structure for all modeled alternatives. Rootless dikes and bullnose chevrons provide adequate space and flow for side channel presence as opposed to the continuous and notched dikes.

29 Sep 2025

Demonstration of Innovative Patching Technologies for Asphalt Pavement Sustainment

Abstract: iHMA and RapidPatch are two asphalt repair materials developed at the US Army Engineer Research and Development Center (ERDC) to provide asphalt patching materials that are readily available, support rapid return to traffic, and yield high quality, long-term performance solutions. The primary objective of this project was to complete multiple demonstrations of asphalt patching with iHMA and RapidPatch at four installations in different climate zones around the United States. These locations included Fort Wainwright (Alaska), Fort Drum (New York), Fort Huachuca (Arizona), and Bradshaw Army Airfield (Hawai‘i). Overall, demonstrations were completed successfully in all climates, providing an opportunity to evaluate patching technologies in real-world environments, some of which are considered untraditional conditions for repairing asphalt. In total, 111 tubes of iHMA and 90 buckets of RapidPatch were used to complete 55.3 ft3 and 49.8 ft3 of patching, respectively, with patch sizes ranging from 4 ft2 up to 20 ft2. Both iHMA and RapidPatch repairs performed well under accelerated trafficking at all installations, exhibiting no more than 6 mm of rutting (less than 1⁄4 in.) after 1,000 passes of heavy truck loading. After 9 to 12 months of operational traffic and environmental exposure, both iHMA and RapidPatch repairs have performed well.

29 Sep 2025

Introduction of the Pivox System—A Low-Cost, Rapidly Deployable Modular Lidar System

Abstract: Terrestrial light detection and ranging instruments can provide extremely valuable data for a multitude of applications in a wide variety of science and engineering fields. However, terrestrial lidar systems (TLS), are prohibitively expensive for many projects and require significant power and data resources to allow for the collection and transmittal of real-time lidar data, limiting their use in remote applications. To address the need for low-cost lidar data collection capabilities in remote environments, the US Army Corps of Engineers, Engineer Research Development Center, Cold Regions Research and Engineering Laboratory, and Geotechnical and Structures Laboratory (GSL) developed the Pivox System. The Pivox System integrates a Livox lidar sensor to a Raspberry Pi, allowing for real-time data collection, processing, and transmittal using a self-contained unit that also includes the power supply and communications equipment. We present data collected using the Pivox System in three diverse environments to measure changes in snow depth, the presence of lake ice, and erosion during a levee overtopping experiment.

26 Sep 2025

Rapid Assessment Tool for Channel Hydraulics and Floodplain Connectivity

Abstract: This technical note (TN) presents a rapid, nationally applicable web application for analyzing channel hydraulics and floodplain connectivity. The tool uses locally derived relative elevation models (REMs) that allow users to quantify hydraulics, like velocity and shear stress, and floodplain connectivity metrics, like inundation extent and storage volume (Haring and Dougherty, forthcoming).* By delineating cross sections directly from publicly available high-resolution terrain, the tool provides a rapid hydraulic assessment without requiring field survey data and also helps prioritize reaches for more detailed assessments.