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Portland State University

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Full-Text Articles in Civil Engineering

Fuel Tank Seismic Stability Program-Informed Displacement Maps Of Portland's Critical Energy Infrastructure Hub, Ana Tijerina Esquino Jul 2026

Fuel Tank Seismic Stability Program-Informed Displacement Maps Of Portland's Critical Energy Infrastructure Hub, Ana Tijerina Esquino

Dissertations and Theses

Oregon's Critical Energy Infrastructure (CEI) Hub in northwest Portland contains a large portion of the state's liquid fuel storage and distribution capacity and is located in an area susceptible to liquefaction and earthquake-induced permanent ground deformation during a Cascadia Subduction Zone earthquake. Initial Seismic Vulnerability Assessments submitted under Oregon's Fuel Tank Seismic Stability program provide valuable facility-specific information, but the assessments vary in subsurface characterization, treatment of fine-grained soils, ground motion selection, and deformation estimation methods. This variability complicates interpretation of regional seismic risk and motivates a consistent corridor-scale analysis.

This thesis develops CPT-informed displacement estimates for representative cross sections …


Scale-Dependent Particle Transport Over Urban-Like Roughness In Turbulent Flow, Rae Riddle Apr 2026

Scale-Dependent Particle Transport Over Urban-Like Roughness In Turbulent Flow, Rae Riddle

Dissertations and Theses

This study employs direct numerical simulation (DNS) to investigate the dispersion of inertial particles in turbulent flow over three-dimensional urban-like roughness at Reτ = 200. Particles with Stokes numbers St = 5, 25, and 100 are tracked over cubic arrays with spanwise spacings Sy from 2h to 32h, where h = δ/8 and δ is the half-channel height, alongside a smooth-wall reference case. The results reveal scale-dependent particle responses characterized by three distinct regimes. First, high-inertia particles (St = 100) align strongly with mean secondary flows, exhibiting organized plumes above roughness elements. Their vertical transport peaks at intermediate spacing …


Effect Of Degree Of Saturation On The Liquefaction Resistance Of Non-Plastic And Low-Plastic Soils, Kayla Rae Sorenson Feb 2026

Effect Of Degree Of Saturation On The Liquefaction Resistance Of Non-Plastic And Low-Plastic Soils, Kayla Rae Sorenson

Dissertations and Theses

Liquefaction and cyclic softening of fine-grained soils pose a significant hazard during earthquakes, yet the cyclic behavior of transitional soils such as silts remains poorly understood. Existing empirical liquefaction evaluation frameworks and ground improvement techniques are largely developed for sands and are not directly applicable to silts, particularly beneath existing infrastructure where conventional mitigation methods are often impractical or cost prohibitive. This knowledge gap is critical in regions such as the Pacific Northwest, where young, loosely deposited silts are prevalent and susceptible to seismic loading.

Microbially induced desaturation (MID) has emerged in recent years as a promising, minimally invasive ground …


Characterizing The Effect Of Plasticity Index On Monotonic And Cyclic Shear Behavior Of Natural Low-Plastic Silt Mixtures, Amir Barati-Nia Feb 2026

Characterizing The Effect Of Plasticity Index On Monotonic And Cyclic Shear Behavior Of Natural Low-Plastic Silt Mixtures, Amir Barati-Nia

Dissertations and Theses

Low-plasticity silts are "transitional" soils prevalent in many seismically active regions, including the Pacific Northwest. Most research in the literature has historically focused on sand materials or clay materials, while low plastic silt does not fit either traditional "sand-like" or "clay-like" frameworks, resulting in a knowledge gap regarding this type of soil. Knowing the behavior of this type of soil is more important because it is susceptible to liquefaction or cyclic softening. Existing research on low-plastic silts is mostly based on either intact soil, where some parameters, such as the overconsolidation ratio (OCR) and plasticity index (PI), cannot be accurately …


An Integrated Multivariate Econometric Modeling Framework For Risky Driving Behavior Related Crashes: Evaluating Crash Risk And Severity Across Zones, Pabitra Kumar Roy Dec 2025

An Integrated Multivariate Econometric Modeling Framework For Risky Driving Behavior Related Crashes: Evaluating Crash Risk And Severity Across Zones, Pabitra Kumar Roy

Dissertations and Theses

Rapid advancements in crash modeling have yet to fully integrate multiple behavior-driven crash types and their severity outcomes within a single, scalable framework, specially in a way that captures the sequential nature of these behaviors where one risky action may amplify another. This study proposed an integrated multivariate econometric framework to jointly model crash frequency and severity outcomes for three major behaviorally driven crash types: alcohol-related, distraction-related, and aggressive-driving-related crashes. Specifically, using Oregon's 2022 census block group-level crash data, we propose an Integrated Multivariate Negative Binomial – Generalized Ordered Probit Fractional Split (IMNB–GOPFS) model to analyze these dimensions simultaneously while …


Seismic Fragility Analysis Of Above-Ground Liquid Storage Tanks, Pooyan Khajeh Shahzanian Sep 2025

Seismic Fragility Analysis Of Above-Ground Liquid Storage Tanks, Pooyan Khajeh Shahzanian

Dissertations and Theses

Liquid storage tanks are critical infrastructure, serving as key storage facilities for various products. As the contents in these tanks are usually highly toxic and flammable, damage to these structures under earthquakes can cause severe consequences, including energy shortage, fire and explosion, and spilling and long-term environmental damages.

Although new liquid storage tanks are designed according to the updated seismic design codes, large numbers of existing storage tanks were built before modern seismic design codes and did not undergo necessary seismic retrofitting. Observations and reports from past earthquakes demonstrate that these older tanks can be highly vulnerable to seismic excitation. …


Geotechnical Centrifuge Test Of A Pile-Supported Wharf In Silt (Test Aep01), Andrew Earl Parrott Mar 2025

Geotechnical Centrifuge Test Of A Pile-Supported Wharf In Silt (Test Aep01), Andrew Earl Parrott

Dissertations and Theses

There have been many documented cases in the U.S. and elsewhere of failure to ports, wharves, and bridges during seismic events due to liquefaction of soils adjacent to foundations. The major design guidelines for surface and maritime transportation structures, such as those offered in ASCE 61-14, Port of Anchorage Seismic Design Manual (POA 2017), AASHTO (2020), Caltrans (2012), and many others, differ considerably on the recommendations for combining the expected inertial and kinematic loads on the pile system. This knowledge gap becomes wider for pile foundations embedded in low plasticity silt, as varying opinions exist on the appropriate characterization of …


Structural Earthquake Resiliency Of Rocking Core Systems With Floor Enabled Recentering, S. Taban Hajimirza Jan 2025

Structural Earthquake Resiliency Of Rocking Core Systems With Floor Enabled Recentering, S. Taban Hajimirza

Dissertations and Theses

The growing need for structural earthquake resiliency, coupled with increasing demands for environmentally sustainable construction, has driven architects and engineers to emphasize the importance of earthquake-resistant mass timber multistory construction in regions prone to high seismic activity. With advancements in building technologies, cross-laminated timber (CLT) has emerged at the forefront of this movement by unlocking new potentials for urban development.

Motivated by the aforementioned demands, this PhD dissertation investigated lateral behavior and earthquake response of a novel lateral force-resisting structural system, known as Floor Recentering Rocking Core (FLR-ROCR). FLR-ROCR is a low-damage recentering mass-timber system that leverages restoring interactions between …


Numerical Study Of Cone Penetration In Calcareous Sands: Investigating Cone Tip Resistance Correction Factors For Crushable Soils, Stephanie Michelle Hyder Mar 2024

Numerical Study Of Cone Penetration In Calcareous Sands: Investigating Cone Tip Resistance Correction Factors For Crushable Soils, Stephanie Michelle Hyder

Dissertations and Theses

The cone penetration test (CPT) is used to characterize the behavior and properties of soils, including the susceptibility to earthquake liquefaction triggering. The cone tip resistance relates to liquefaction susceptibility through relative density, where relative density is closely related to both cone tip resistance and liquefaction susceptibility. Currently, published methods of estimating liquefaction potential (i.e., cyclic resistance ratio) are based on silica sands and do not properly characterize calcareous sands. The measured cone tip resistance in calcareous sands is lower than in silica sands at the same relative density; this difference is generally attributed to the higher compressibility of calcareous …


Uncertainty Quantification Of Live Load Effect In Buried Rc Box Culverts, Mohd Firoj Dec 2023

Uncertainty Quantification Of Live Load Effect In Buried Rc Box Culverts, Mohd Firoj

Dissertations and Theses

Although buried and mostly invisible to the traveling public, bridge-sized culverts (i.e., culverts with span around or longer than 20 ft) account for a large proportion of state-managed bridges. As per Oregon Department of Transportation inventory, there are approximately 35,000 culverts in the state highway system. Among them, 10,862 are in poor conditions and need to be analyzed for load rating purposes. The prediction and understanding of live load effects in culverts are crucial to the design, evaluation, and life-cycle maintenance of culverts. These live load effects include maximum bending moments and shear forces at different critical cross sections.

This …


Biological Nitrogen And Phosphorus Removal From Wastewater Under Low Dissolved Oxygen (Ldo) Conditions, Bashar Al-Daomi Dec 2023

Biological Nitrogen And Phosphorus Removal From Wastewater Under Low Dissolved Oxygen (Ldo) Conditions, Bashar Al-Daomi

Dissertations and Theses

This study examines the complexities of the integration of different technologies for nutrient removal, investigating parameters like sludge residence time (SRT), carbon-to-nitrogen (C/N) ratio, Anaerobic/Oxic (A/O), and Anaerobic/Oxic/Anoxic (A/O/A) systems, continuous and intermittent aeration regimes, and air OFF/air ON periods ratios for efficient nitrogen and phosphorus removal.

Two continuous aeration systems were implemented: The first aimed to carry out a simultaneous nitrification and denitrification (SNdN) process for nitrogen and phosphorus removal under low dissolved oxygen (DO) and C/N ratio conditions. This system operated with 4.5-5-day total sludge age in a single-stage anaerobic/oxic (A/O)-SBR, performing stepwise DO reduction at varying DO …


Probability Distribution Fitting For Censored Data: A Practical Guide For Survival Analysis Of Nbi Data For Concrete Bridge Decks In Oregon, Asmaa Almeshaileh Nov 2023

Probability Distribution Fitting For Censored Data: A Practical Guide For Survival Analysis Of Nbi Data For Concrete Bridge Decks In Oregon, Asmaa Almeshaileh

Dissertations and Theses

Many sophisticated statistical models and analyses have been proposed to analyze datasets derived from the national bridge inventory (NBI). These objectives range from creating an understanding of the factors that drive the deterioration of bridge members to providing agencies with quantitative information for their maintenance and repair decisions. As these models become increasingly sophisticated and difficult to comprehend and implement, practicing engineers and owners are less likely to use them. Often, however, grouping data intuitively, for example, per a select structure type or condition rating and analyzing them using prescriptive statistics such as distribution fitting, does not only lie in …


A Bayesian Network-Based Methodology For Improved Bridge Load Rating And Asset Management, Jeffery Mark Roberts Nov 2023

A Bayesian Network-Based Methodology For Improved Bridge Load Rating And Asset Management, Jeffery Mark Roberts

Dissertations and Theses

From the day a new structure is made available for use, to the day that the structure is no longer able to fulfill an intended purpose, structural safety is a vital interest. Managing a portfolio of structures can be a difficult undertaking for an asset manager, particularly if different types of structures are being maintained. The goal is to manage assets in the most efficient manner which can be influenced by, at a minimum, safety and financial concerns.

A potential tool for an asset manager or owner is the use of Bayesian Networks (BNs). When a BN is used to …


Load Effects Of Truck Platooning On Existing Bridges In Oregon, Patricia Oleson Jul 2023

Load Effects Of Truck Platooning On Existing Bridges In Oregon, Patricia Oleson

Civil and Environmental Engineering Master's Project Reports

Truck Platooning (TP) involves managing multiple trucks closely together to reduce aerodynamic drag. While TP offers benefits such as fuel savings, emission reductions, and enhanced safety, it raises concerns for existing infrastructure. This study reviews literature on TP and conducts bridge analyses comparing representative truck platoon configurations allowed under Oregon law with current truck loadings. It also explores the effects of truck head spacing and bridge span lengths, utilizing the research results to calculate rating factors using real-world case studies. The objective is to identify truck platoon configurations that may exceed acceptable load levels for Oregon bridges. The findings will …


Uncertainty Quantification And Fragility Development Of Deteriorating Rc Bridge Piers, Ayush Bhandari Mar 2023

Uncertainty Quantification And Fragility Development Of Deteriorating Rc Bridge Piers, Ayush Bhandari

Dissertations and Theses

Corrosion can reduce structural capacity and increase the risk of bridge damage/failure under extreme events. The impact of corrosion on seismic fragility of bridges has been well studied. However, the methodology used in most existing studies requires detailed information on the structural design and condition of a bridge, which is a major hindrance in conducting seismic risk assessment for a large population of bridges. Furthermore, existing studies do not adequately address the time-dependency of uncertainties associated with fragility curve development. This study presents a methodology to generate time-dependent seismic fragility curves for deteriorating highway bridges based only on the limited …


Pile-Supported Wharves Subjected To Inertial Loads And Lateral Ground Deformations. Ii: Guidelines For Equivalent Static Analysis, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Scott Schlechter, Nason Mccullough Nov 2022

Pile-Supported Wharves Subjected To Inertial Loads And Lateral Ground Deformations. Ii: Guidelines For Equivalent Static Analysis, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Scott Schlechter, Nason Mccullough

Civil and Environmental Engineering Faculty Publications and Presentations

An equivalent static analysis (ESA) procedure is proposed for the design of pile-supported wharves subjected to combined inertial and kinematic loads during earthquakes. The accuracy of the ESA procedure was evaluated against measurements from five large-scale centrifuge tests. The wharf structures in these tests were subjected to a suite of recorded ground motions and the associated superstructure inertia, as well as earthquake-induced slope deformations of varying magnitudes. It is shown that large bending moments at depths greater than 10 pile diameters were primarily induced by kinematic demands and can be estimated by applying soil displacements only (i.e., 100% kinematic). In …


Multimodal Imaging Of Structural Concrete Using Image Fusion And Deep Learning, Sina Mehdinia Aug 2022

Multimodal Imaging Of Structural Concrete Using Image Fusion And Deep Learning, Sina Mehdinia

Dissertations and Theses

Concrete structures may be exposed to a variety of loads and environments during their service life. Non-destructive testing (NDT) techniques can be helpful in evaluating the condition of a structure. Imaging provides a visual representation of the interior of concrete and its condition non-destructively. Ground penetrating radar (GPR) and ultrasonic echo array (UEA) using electromagnetic and stress waves, respectively, provide the data that can be used to reconstruct an image. In this PhD dissertation, image reconstruction and fusion algorithms, simulation, and a deep learning model were investigated with the goal to lay the foundation for enhanced imaging applications for concrete. …


Design And Evaluation Of A Prototype Low-Damage Beam-Column Connection For Mass Timber Moment Frames, Samuel D. Richmann Mar 2022

Design And Evaluation Of A Prototype Low-Damage Beam-Column Connection For Mass Timber Moment Frames, Samuel D. Richmann

Civil and Environmental Engineering Master's Project Reports

A moment-resisting, beam-column connection for mass timber moment frames was developed, designed and tested. The design was intended to limit damage to the timber members by creation of a ductile failure mechanism in steel U-shaped flexural plates (UFPs). Using design equations developed by previous research on UFPs by Baird, et al. (2014) as well as accepted design practices from the NDS and AISC, the components were sized to eliminate failure in the timber. The connection was tested using a quasi-static lateral displacement method following the procedure outlined in section K2.4b of AISC 341-16. A vertical load was placed on the …


Seismic Performance Design Criteria Of Existing Bridge Bent Plastic Hinge Region And Rapid Repair Measures Of Earthquake Damaged Bridges Considering Future Resilience, A K M Golam Murtuz Mar 2022

Seismic Performance Design Criteria Of Existing Bridge Bent Plastic Hinge Region And Rapid Repair Measures Of Earthquake Damaged Bridges Considering Future Resilience, A K M Golam Murtuz

Dissertations and Theses

The main objective of this research was to evaluate the seismic performance of existing sub-standard reinforced concrete (RC) bridge column-spread footing subassemblies and to quantify the material strain limits through a full-scale experimental program. A total of six column-footing test specimens with pre-1990 construction details were subjected to reverse cyclic lateral loading, utilizing a conventional three-cycle symmetric loading protocol and a protocol representing the demands expected from a CSZ earthquake. Additionally, the tests were designed so that variable axial loading could be applied to simulate the secondary load effects experienced during an earthquake in a column that is part of …


Maximum Profit Facility Location And Dynamic Resource Allocation For Instant Delivery Logistics, Darshan Chauhan, Avinash Unnikrishnan, Stephen D. Boyles Jan 2022

Maximum Profit Facility Location And Dynamic Resource Allocation For Instant Delivery Logistics, Darshan Chauhan, Avinash Unnikrishnan, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

Increasing e-commerce activity, competition for shorter delivery times, and innovations in transportation technologies have pushed the industry toward instant delivery logistics. This paper studies a facility location and online demand allocation problem applicable to a logistics company expanding to offer instant delivery service using unmanned aerial vehicles or drones. The problem is decomposed into two stages. During the planning stage, the facilities are located, and product and battery capacity are allocated. During the operational stage, customers place orders dynamically and real-time demand allocation decisions are made. The paper explores a multi-armed bandit framework for maximizing the cumulative reward realized by …


Determinant Factors Of Bicyclist Injury Severity At Signalized And Unsignalized Intersections, Apy Das Nov 2021

Determinant Factors Of Bicyclist Injury Severity At Signalized And Unsignalized Intersections, Apy Das

Dissertations and Theses

Bicycling is becoming increasingly popular in Oregon and the US in general due to its environment friendliness as well as health benefits. With Oregon's population projected to increase by more than 30% over the next 30 years, improving the safety of the transportation network for persons on bicycles is important. In Oregon, majority of the bicyclist crashes occur at intersections. This thesis seeks to identify the determinant factors that significantly impact bicyclist crash injury severity at intersections. A mixed logit framework that accounts for any unobserved heterogeneity in the data and allows the estimated parameters to randomly vary across observations …


Undrained Cyclic Loading Of Low Plasticity Silty Soils In The Pacific Northwest Using Laboratory And Field Cyclic Shear Testing, Angelica Melissa Preciado Reyes Sep 2021

Undrained Cyclic Loading Of Low Plasticity Silty Soils In The Pacific Northwest Using Laboratory And Field Cyclic Shear Testing, Angelica Melissa Preciado Reyes

Dissertations and Theses

The cyclic behavior of a fine-grained low plasticity silty soil (plasticity index of approximately 15) at a site in Portland, Oregon, is characterized using a field and laboratory cyclic shear test program. The field cyclic tests were performed using the NHERI@UTexas large mobile shakers T-Rex and Rattler. The laboratory tests were performed using resonant column torsional shear and cyclic direct simple shear devices. This testing program's results were used to evaluate the soil's potential to develop excess pore water pressure with cyclic shear strains ranging from 0.00001% to 3%. The laboratory cyclic test results are compared against field cyclic test …


E-Scooter Safety And How To Improve It, Eric Valentino Aug 2021

E-Scooter Safety And How To Improve It, Eric Valentino

altREU Projects

In the last few years, electronic scooters have taken over cities as a means of personal transportation. Between 2017 and 2019 alone, over 30 million trips were recorded across over 100 cities in the US. These scooters pose a safety risk, as 20 in 100,000 trips will result in injury of the rider. On top of this, scooters can cause damage to property, injury pedestrians and motor vehicle drivers, as well as obstruct important infrastructure such as wheelchair ramps. For these reasons, it is important to develop an understanding of the factors that contribute to e-scooter related injuries in order …


Kinematic Demands On Pile-Supported Wharves Due To Liquefaction-Induced Lateral Ground Deformations, Thomas John Torkelson Ii Jul 2021

Kinematic Demands On Pile-Supported Wharves Due To Liquefaction-Induced Lateral Ground Deformations, Thomas John Torkelson Ii

Dissertations and Theses

Kinematic demands from lateral soil deformations can be a major cause of damage to maritime and highway transportation structures such as wharves, ports, and bridges. Data from five centrifuge tests on pile-supported wharves were used to evaluate the accuracy of Newmark Sliding Block Analysis in estimating the kinematic demands on piles. The piles in the centrifuge tests were subjected to varying degrees of liquefaction-induced lateral ground deformations. Pile-pinning effects were included in the analysis by incorporating the lateral pile resistance in the limit-equilibrium slope stability analysis. The results of the analysis have shown that the median Newmark displacements better estimated …


Using Quantitative Stereology On High Resolution Sem Images To Estimate Diatom Percentages, Ariadna Covarrubias Ornelas Jul 2021

Using Quantitative Stereology On High Resolution Sem Images To Estimate Diatom Percentages, Ariadna Covarrubias Ornelas

Dissertations and Theses

Diatoms are single-celled organisms of various shapes and sizes typically found in aquatic environments. When diatoms die, the organic material decomposes, and the outer skeletons (i.e., frustules) settle and accumulate as sedimentary deposits. These soils, called diatomaceous soils, exhibit nontraditional behavior since the diatom particles are typically hollow skeletons composed of amorphous silica with intricately patterned and abrasive surfaces. Recent studies have shown that diatomaceous soils are challenging geomaterials since even a small percentage of diatom particles will notably affect engineering behavior. Furthermore, laboratory studies on diatomaceous soil mixtures have demonstrated that many engineering soil properties depend on the percentage …


Field Trials And Long-Term Monitoring Of Microbially-Induced Desaturation For The Treatment Of Liquefiable Silty Soils, Kayla Rae Sorenson Jul 2021

Field Trials And Long-Term Monitoring Of Microbially-Induced Desaturation For The Treatment Of Liquefiable Silty Soils, Kayla Rae Sorenson

Dissertations and Theses

Earthquake liquefaction hazards in silty soils are a critical problem in Portland, Oregon, and other areas around the world. This is a particular problem for existing facilities founded on liquefiable soils, for which there exists no cost-effective liquefaction mitigation solution at the present time. It is essential from both a seismic safety and a seismic resilience perspective to be able to mitigate potentially liquefiable soils underneath existing structures, and to do so in a cost-effective manner. Recent studies suggest that liquefaction mitigation using microbially-induced desaturation (MID) may provide this capability.

The objective of MID is to reduce earthquake-induced excess pore …


Distributionally Robust Optimization Utilizing Facility Location Problems, Elijah Kling Apr 2021

Distributionally Robust Optimization Utilizing Facility Location Problems, Elijah Kling

Civil and Environmental Engineering Undergraduate Honors Theses

Facility location problems are used in widespread application in transportation, freight, supply chain, and logistics problems. Models can be developed as deterministic, where all parameters are known, or robust, where a parameter has uncertainty. This thesis explores a new method for developing robust formulation and compares the implications of assuming values for this uncertain parameter. Two models are solved, and both are compared against their deterministic counterparts using numerical analysis. By manipulating the input parameters and considering real world implications of the solutions, either the robust or deterministic can show better performance.


The Influence Of Channel Deepening On Tides, River Discharge Effects, And Storm Surge, Stefan A. Talke, Ramin Familkhalili, David A. Jay Apr 2021

The Influence Of Channel Deepening On Tides, River Discharge Effects, And Storm Surge, Stefan A. Talke, Ramin Familkhalili, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

We combine archival research, semi-analytical models, and numerical simulations to address the following question: how do changes to channel geometry alter tidal properties and flood dynamics in a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes? Records in the Saint Johns River Estuary since the 1890s show that tidal range has doubled in Jacksonville, Florida. Near the estuary inlet, tidal discharge approximately doubled but tidal amplitudes increased only ~6%. Modeling shows that increased shipping channel depths from 5-6 to ~13m drove the observed changes, with other factors like channel shortening and width reduction producing comparatively minor effects. …


Maximum Coverage Facility Location Drone Routing Problem With Multiple Trip Stops, Marie Roza Apr 2021

Maximum Coverage Facility Location Drone Routing Problem With Multiple Trip Stops, Marie Roza

Civil and Environmental Engineering Undergraduate Honors Theses

Integer linear optimization can be used to formulate routing problems as models to find optimal solutions given a set of inputs and constraints. In this research, Chauhan et al.'s publication, "Maximum coverage capacitated facility location problem with range constrained drones," is expanded upon by modeling a facility location problem with two-to-one drone deliveries. The model analyzes a set of potential facilities that are available to meet the demands of a set of demand points. The drone delivery routes are modeled with the assumption that each opened facility is assigned one drone that can fulfill up to two demand points’ demands …


Modeling The Effectiveness Of Cooling Trenches For Stormwater Temperature Mitigation, Scott A. Wells Jan 2021

Modeling The Effectiveness Of Cooling Trenches For Stormwater Temperature Mitigation, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Due to elevated runoff stormwater temperatures from impervious areas, one management strategy to reduce stormwater temperature is the use of underground flow through rock media termed a cooling trench. This paper examines the governing equations for the liquid phase and media phases for modeling the temperature leaving a cooling trench assuming that changes in temperature occurred longitudinally through the cooling trench. This model is dependent on parameters such as the media type, porosity, media initial temperature, inflow rate, and inflow temperature. Several approaches were explored mathematically for evaluating the change in temperature of the water and the cooling trench media. …