3 Jun 2021

Finite element analysis of quoin block deterioration and load transfer mechanisms in miter gates: pintle and pintle connections

Abstract: The U.S. Army Corps of Engineers (USACE) currently operates and maintains approximately 193 commercially active lock sites with 239 locks and dams spanning nearly 12,000 miles. These networks of water channels are used to transport 600 million tons of domestic cargo, generating $405 billion in revenue annually. Nearly 60% of these structures in operation are over 50 years old and have reached design life. A failure of the miter gates could result in a major negative impact on the economy and on the ability to maintain flood control. Administrators need recommendations to better prioritize maintenance and repair of the USACE miter gates. This work investigated the influence of miter gate’s quoin block degradation on load transfer to the pintle and/or pintle connections. Results of finite element analysis are reported for the quoin block degradation simulated levels of 0%, 25%, 50%, and 75%. The parametric study shows the overstressed regions are the pintle neck and bolt-hole regions. To improve pintle designs so they may better mitigate detrimental environmental based deterioration effects, this work recommends (1) increasing the thickness of the bolt-hole connection region and (2) adding ribbing reinforcement around the neck area of the pintle.

3 Jun 2021

In situ analysis and visualization to enable better workflows with CREATE-AV™ Helio

Abstract: The CREATE-AV™ Helios CFD simulation code has been used to accurately predict rotorcraft performance under a variety of flight conditions. The Helios package contains a suite of tools that contain almost the entire set of functionality needed for a variety of workflows. These workflows include tools customized to properly specify many in situ analysis and visualization capabilities appropriate for rotorcraft analysis. In situ is the process of computing analysis and visualization information during a simulation run before data is saved to disk. In situ has been referred to with a variety of terms including co-processing, covisualization, coviz, etc. In this paper we describe the customization of the pre-processing GUI and corresponding development of the Helios solver code-base to effectively implement in situ analysis and visualization to reduce file IO and speed up workflows for CFD analysts. We showcase how the workflow enables the wide variety of Helios users to effectively work in post-processing tools they are already familiar with as opposed to forcing them to learn new tools in order post-process in situ data extracts being produced by Helios. These data extracts include various sources of information customized to Helios, such as knowledge about the near- and off-body grids, internal surface extracts with patch information, and volumetric extracts meant for fast post-processing of data. Additionally, we demonstrate how in situ can be used by workflow automation tools to help convey information to the user that would be much more difficult when using full data dumps.

3 Jun 2021

Elevation of underlying basement rock, Ogdensburg Harbor, NY

Abstract: Over six linear miles of shallow acoustic reflection geophysical data were collected in an 800 ft by 300 ft survey region at Ogdensburg Harbor, Ogdensburg, NY. To better accommodate modern commercial vessels and expand the harbor’s capacity, the current navigable depth of -19 ft Low Water Depth (LWD) needs to be increased to -28 ft LWD, and an accurate map of the nature of the riverbed material (e.g., unconsolidated sediment, partially indurated glacial till, or bedrock) is required to effectively plan for removal. A total of 28 boreholes were previously collected to map the stratigraphy, and the effort revealed significant spatial variability in unit thickness and elevation between adjacent boreholes. To accurately map this variable stratigraphy, chirp sub-bottom profiles were collected throughout the region, with an average line spacing of 13 ft. These sub-bottom data, validated and augmented by the borehole data, resulted in high-resolution spatial maps of stratigraphic elevation and thickness for the study area. The data will allow for more accurate assessment of the type and extent of different dredging efforts required to achieve a future uniform depth of -28 ft LWD for the navigable region.

2 Jun 2021

AIS data case study: quantifying connectivity for six Great Lakes port areas from 2015 through 2018

Abstract: This Coastal and Hydraulics Engineering Technical Note presents results from a preliminary examination of commercial vessel traffic connectivity between six major port areas on the Great Lakes using Automatic Identification System data collected from 2015 to 2018. The six port areas included in this study are Calumet Harbor, IL and IN; Cleveland, OH; Detroit, MI; Duluth-Superior, MN and WI; Indiana Harbor, IN; and Two Harbors, MN. These six locations represent an important subset of the more than 100 federally authorized navigation projects in the Great Lakes maintained by the US Army Corps of Engineers. The results are presented in the context of USACE resilience-related policy initiatives as well as the larger topic of maritime system resilience.

2 Jun 2021

Multi-objective source scaling experiment

Abstract: The U.S. Army Engineer Research and Development Center (ERDC) performed an experiment at a site near Vicksburg, MS, during May 2014. Explosive charges were detonated, and the shock and acoustic waves were detected with pressure and infrasound sensors stationed at various distances from the source, i.e., from 3 m to 14.5 km. One objective of the experiment was to investigate the evolution of the shock wave produced by the explosion to the acoustic wavefront detected several kilometers from the detonation site. Another objective was to compare the effectiveness of different wind filter strategies. Toward this end, several sensors were deployed near each other, approximately 8 km from the site of the explosion. These sensors used different types of wind filters, including the different lengths of porous hoses, a bag of rocks, a foam pillow, and no filter. In addition, seismic and acoustic waves produced by the explosions were recorded with seismometers located at various distances from the source. The suitability of these sensors for measuring low-frequency acoustic waves was investigated.

28 May 2021

Challenges in evaluating efficacy of scientific visualization for usability and aesthetics

Abstract: This paper presents the results of a study to evaluate the efficacy of scientific visualization for multiple categories of users, including both domain experts as well as users from the general public. Efficacy was evaluated for understanding, usability, and aesthetic value. Results indicate that aesthetics play a critical, but complex role in enhancing both user understanding and usability.

27 May 2021

Long-term performance of sustainable pavements using ternary blended concrete with recycled aggregates

Abstract: Dwindling supplies of natural concrete aggregates, the cost of landfilling construction waste, and interest in sustainable design have increased the demand for recycled concrete aggregates (RCA) in new portland cement concrete mixtures. RCA repurposes waste material to provide useful ingredients for new construction applications. However, RCA can reduce the performance of the concrete. This study investigated the effectiveness of ternary blended binders, mixtures containing portland cement and two different supplementary cementitious materials, at mitigating performance losses of concrete mixtures with RCA materials. Concrete mixtures with different ternary binder combinations were batched with four recycled concrete aggregate materials. For the materials used, the study found that a blend of portland cement, Class C fly ash, and blast furnace slag produced the highest strength of ternary binder. At 50% replacement of virgin aggregates and ternary blended binder, some specimens showed comparable mechanical performance to a control mix of only portland cement as a binder and no RCA substitution. This study demonstrates that even at 50% RCA replacement, using the appropriate ternary binder can create a concrete mixture that performs similarly to a plain portland cement concrete without RCA, with the added benefit of being environmentally beneficial.

25 May 2021

Holistic and Reductionist Thinker: A Comparison Study Based on Individuals’ Skillset and Personality Types

Abstract: As organizations operate in turbulent and complex environments, it has become a necessity to assess the systems thinking (ST) skills, personality types (PTs), and demographics of practitioners. In this study, we investigated the relationship between practitioners’ ST profile, their PTs profiles and demographic characteristics in the domain of complex system problems. The objective of this study is to address the current gap in the literature – lack of studies dedicated to predicting practitioners’ ST profile based on their PTs and demographics characteristics. A total of 258 practitioners with different demographics and PTs provided the data. The results show that (1) practitioners can be classified based on their ST skills scores into two clusters: holistic and reductionist (that is, ST profile), (2) each cluster has different PTs profiles and demographic characteristics, and (3) practitioner’s ST profile can be predicted, with good accuracy, based on their PTs profile and demographic characteristics.

25 May 2021

Applying Resilience Concepts to Inland River Systems

Abstract: As environmental uncertainty increases, incorporating resilience into project assessments, research recommendations, and future plans is becoming even more critical. This US Army Engineer Research and Development Center special report (SR) demonstrates how the concepts of resilience can be applied in a uniform framework and illustrates this framework through existing case studies on large inland river systems. This SR presents the concepts of resilience in inland river systems, the application of these concepts across disciplines, basic parameters of a resilience assessment, and the challenges and opportunities available for incorporating a more holistic approach to understanding resilience of the US Army Corps of Engineers mission areas on inland rivers. Finally, these concepts are demonstrated in several case studies in the United States to exemplify how these parameters have been applied to improve the overall performance of the system.

21 May 2021

Approaches for Assessing Riverine Scour

Abstract: Calculating scour potential in a stream or river is as much a geomorphological art as it is an exact science. The complexity of stream hydraulics and heterogeneity of river-bed materials makes scour predictions in natural channels uncertain. Uncertain scour depths near high-hazard flood-risk zones and flood-risk management structures lead to over-designed projects and difficult flood-risk management decisions. This Regional Sediment Management technical report presents an approach for estimating scour by providing a decision framework that future practitioners can use to compute scour potential within a riverine environment. This methodology was developed through a partnership with the US Army Engineer Research and Development Center, Hydrologic Engineering Center, and St. Paul District in support of the Lower American River Contract 3 project in Sacramento, CA.