30 Jan 2025

Investigation of Bioplastic Degradation for Military In-Field Applications Implementation of Sustainable Practices into the US Military for Rapid Biodegrading Polylactic Acid (PLA) Plastic in Compostable Environments

Abstract: The Army Climate Strategy has identified goals to reduce greenhouse gas (GHG) emissions to reach net-zero Army GHG emissions by 2050. Producing fossil-fuel-based plastics releases GHG emissions and plastic bottles are difficult to dispose, especially in contingency locations. Soldiers prefer hydrating with plastic water bottles, which leads to GHG emissions. This project investigates using bioplastics for water bottles. These bioplastics are produced from natural materials and can break down faster with alternative disposal methods, such as composting. Challenges include finding a material with a stable shelf life and the capability to hold water, but also one that that degrades with ease in the right composting environment. As part of this project, partners at the University of Minnesota are developing a new polylactic acid (PLA) material to fit the material properties needed for this application. Their research is ongoing. Construction Engineering Research Laboratory (CERL) researchers tested commercial PLA in calorimeter and incubator studies and with a full-scale demonstration of the commercial composting Sustainable Generation Mobile System. The PLA did not completely degrade, and testing showed mixed results on finished compost quality. Recommendations included continued testing, experimenting with other bioplastics, and changing compost feedstock variables.

30 Jan 2025

Rapid Assessment Tools for Estimating Trafficability of Low Volume Roads

Abstract: Rapid assessment of low-volume road surfaces remains a challenge when attempting to forecast allowable vehicle crossings. Variations in soil type, compaction effort, and moisture content of the soil can greatly affect trafficability, and predictive equations for soil deformation under vehicle loads often have reduced reliability for low-strength materials. Portable tools to characterize soil stiffness and corresponding relationships to load-induced deformation are needed. In this effort, researchers performed comparative testing of multiple rapid assessment tools as potential devices for giving estimations of vehicle trafficability. The test devices included a Clegg hammer and light weight deflectometer as instruments that measure response from impulse loading. Silty sand with and without chemical stabilization (using cement) at varying moisture content were used for testing. These soil states represented very weak conditions capable of supporting fewer than 50 vehicle passes to moderate strength conditions capable of supporting several thousand vehicle passes. Data from full-scale tests were used to correlate allowable traffic with data obtained from the rapid assessment tools. Recommendations from the effort include ranges of response data to categorize low-volume road surfaces based on their ability to handle ranges of vehicle loadings.

30 Jan 2025

Improved Trafficability Over Soft Soils Using Ground Matting

Abstract: Soft soils pose mobility challenges, even for vehicles designed with superior off-road capabilities. When numerous vehicles travel the same path, permanent deformation of the soil can result in rut depths that exceed vehicle ground clearance. These challenges can be overcome by modifying ground conditions to improve bearing capacity or spreading wheel loads over a greater area. Researchers at the U.S. Army Engineer Research and Development Center conducted field tests to quantify the performance benefits of a ground matting system made of connected fiberglass panels designed to improve vehicle mobility on soft soils. Soil conditions included silt, sand, and highly organic soil with varying strength. Test vehicles included wheeled trucks with gross weights of approximately 6350 kg per axle. Performance of the matting system was assessed by the number of allowable vehicle crossings with and without matting present. Results from testing showed that allowable number of vehicles increased by at least a factor of ten on the weakest soils. Data presented herein includes geotechnical site characterization, soil deformation as a function of traffic, and material characteristics for the fiberglass matting system.

28 Jan 2025

Montgomery Locks and Dam, Ohio River: Navigation Approach Physical Model

Abstract: A physical model study of the Montgomery Locks and Dam was conducted to optimize the navigation conditions for the new riverside lock and guard wall design developed by the Pittsburgh District. A 1:100 Froude scale physical model was built to evaluate the navigation conditions for tows entering and exiting the locks in the upstream and downstream approaches. Conditions tested were Existing Conditions, Deconstruction Sequences, Construction Sequences, and Proposed Design. Data were also collected for impact analysis on the upstream and downstream riverside guard walls. The final design consisted of an upstream ported guard wall that is 1,000 ft in length and a downstream solid guard wall that is 800 ft in length. The implementation of submerged dikes in the upstream and downstream approaches improve navigation conditions significantly and are an essential part of the final design. Details are shown in Section 3.5 of this report.

28 Jan 2025

“One Grand, Glorious National Cause”: A Cultural Geography of the Veterans Affairs Built Environment

Abstract: The United States government has a long history of providing medical, financial, and burial benefits to American Veterans. The Department of Veterans Affairs (VA) and its predecessor agencies constructed much of the built environment that served as a conduit for these benefits. Today, the VA manages and maintains more than 15,000 buildings and structures to serve the Veteran community. To facilitate the transfer of property rights of its vacant and underutilized properties and ensure compliance with Section 106 of the National Historic Preservation Act, the Advisory Council on Historic Preservation issued a Program Comment at the request of the VA on 26 October 2018. The Program Comment mitigation requires the VA to produce a readily accessible public-benefit document of interest to a wide audience composed of Veterans and lay people. This book provides that public-benefit document through a cultural geography of the built environment of VA facilities. This book focuses on the sense of place developed by Veterans toward VA facilities and covers three generational periods as defined by the VA: post–Civil War through World War I, World War I through the end of World War II, and post–World War II through 1958.

21 Jan 2025

Moffett Field Naval Chapel (Building 86) and Boiler House (Building 87): Historic Materials Maintenance Manual

Abstract: The Moffett Field Naval Chapel and boiler house are located on the Moffett Federal Airfield, Santa Clara, California. Constructed circa 1945, both buildings are eligible for the National Register of Historic Places (NRHP) under Criterion A for associations with the post–WWII Moffett Field expansion and under Criterion C as a representative example of Navy Bureau of Yards and Docks chapel construction and as a true representative example of the Spanish colonial revival style in the region. Their period of significance is 1945–1986, before major renovations were completed at the site. All buildings, especially historic ones, require regular planned maintenance and repair. The most notable cause of historic building element failure or decay is not the fact that the historic building is old, but rather it is caused by incorrect or inappropriate repair and basic neglect of the historic building fabric. This document is a maintenance manual compiled with as-is conditions of construction materials of the Moffett Field Naval Chapel. The Secretary of Interior Guidelines on rehabilitation and repair per material are discussed to provide a guide to maintain this historic building. This report satisfies Section 110 of the National Historic Preservation Act (NHPA) of 1966 as amended and will help to manage this historic building.

21 Jan 2025

Engineering With Nature: Natural Infrastructure for Mission Readiness at U.S. Navy and Marine Corps Installations

Abstract: This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at eight U.S. Navy and Marine Corps military installations to achieve increased resilience through natural infrastructure.

9 Jan 2025

National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams: Final Version

Abstract: The ordinary high water mark (OHWM) defines the lateral extent of non-tidal aquatic features in the absence of adjacent wetlands in the United States. The federal regulatory definition of the OHWM, 33 CFR 328.3(c)(4), states the OHWM is “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as [a] clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” This is the first manual to present a methodology for nationwide identification and delineation of the OHWM. A two-page data sheet and field procedure outline a weight-of-evidence (WOE) methodology to organize and evaluate observations at stream sites. This manual presents a consistent, science-based method for delineating the OHWM in streams. It also describes regional differences and challenges in identifying the OHWM at sites disturbed by human-induced or natural changes and illustrates how to use remote data to structure field inquiries and interpret field evidence using the principles of fluvial science. The manual demonstrates that, in many landscape settings, the OHWM may be located near the bankfull elevation.

7 Jan 2025

Exploring Lidar Odometry Within the Robot Operating System

Abstract: Here, we explore various lidar odometry approaches (with both 3 and 6 degrees of freedom) in simulation. We modified a virtual model of a TurtleBot3 robot to work with the various odometry approaches and evaluated each method within a gazebo simulation. The gazebo model was configured to generate an absolute ground truth for comparison to the odometry results. We used the evo package to compare the ground truth with the various lidar odometry values. The results for KISS-ICP and laser scan matcher (LSM), including two simultaneous localization and map-ping (SLAM) approaches, Fast Lidar-Inertial Odometry (FAST-LIO), and Direct Lidar Odometry (DLO), are provided and discussed. We also tested one of the approaches on our physical robot.

7 Jan 2025

Geomorphic Assessment of the St. Francis River Phase II

Abstract: Significant sedimentation issues persist within the St. Francis Basin as a result of extensive drainage alterations. The objective of this study is to characterize the bed and bank sediment throughout the study reach and identify potential sources of sediment contributing to the sanding issues below Holly Island. The sedimentation below Holly Island increases the Memphis District’s maintenance needs in the St. Francis River Basin by requiring millions of dollars for channel cleanout and bank stabilization projects. This effort synthesizes prior geomorphic studies and existing survey data to break the study reach into seven geomorphic reaches of interest. Simultaneously, 151 bed samples and 137 bank samples were collected to characterize the sediments within the study reach to develop a data dictionary for future sediment budget development. Results show the St. Francis River is a poorly sorted, sand-bed river overlain by 10 to 20 feet of silts and clays along the banks. Iron Bridge to Highway U (Reach 1-3) may reach pseudo-stability so long as existing grade-control structures and bank stabilization features remain. Reach 6, between St. Francis and Brown’s Ferry, is evolving with one cutoff forming and one cutoff recently complete. This reach may be a source of sediment to downstream reaches.