Civil and Environmental Engineering Commons^™

A Hybrid Approach To Improve Flood Forecasting By Combining A Hydrodynamic Flow Model And Artificial Neural Networks, Li Li, Kyong Soo Jun

Civil and Environmental Engineering Faculty Publications and Presentations

Climate change is driving worsening flood events worldwide. In this study, a hybrid approach based on a combination of the optimization of a hydrodynamic model and an error correction modeling that exploit different aspects of the physical system is proposed to improve the forecasting accuracy of flood water levels. In the parameter optimization procedure for the hydrodynamic model, Manning’s roughness coefficients were estimated by considering their spatial distribution and temporal variation in unsteady flow conditions. In the following error correction procedure, the systematic errors of the optimized hydrodynamic model were captured by combining the input variable selection method using partial …

Robust Multi-Period Maximum Coverage Drone Facility Location Problem Considering Coverage Reliability, Darshan Rajesh Chauhan, Avinash Unnikrishnan, Miguel A. Figliozzi, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

This study proposes a multi-period facility location formulation to maximize coverage while meeting a coverage reliability constraint. The coverage reliability constraint is a chance constraint limiting the probability of failure to maintain the desired service standard, commonly followed by emergency medical services and fire departments. Further, uncertainties in the failure probabilities are incorporated by utilizing robust optimization using polyhedral uncertainty sets, which results in a compact mixed-integer linear program. A case study in the Portland, OR metropolitan area is analyzed for employing unmanned aerial vehicles (UAVs) or drones to deliver defibrillators in the region to combat out-of-hospital cardiac arrests. In …

Site-Specific Site Response Analysis And Cascadia Subduction Zone Ground Motions Evaluation For A Site Near Portland, Brian Ackerman

Civil and Environmental Engineering Master's Project Reports

Site-specific ground motions, site-specific site response analysis, and development of site-specific acceleration ground spectra at the ground surface was developed per ASCE 7-10 for the Kirkland Renaissance Boardwalk, a site in Vancouver, Washington.

Synthetic broadband ground motions developed specifically for Cascadia Subduction Zone (CSZ) megathrust earthquake were used for site-response analysis. The results of site-specific site response analyses using the strong motions were compared with the results from the 5 motions considered for the ASCE 7-10 procedure. The effect of motion duration and other ground motion intensity measures on the results of the site-specific site response analysis was investigated.

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Measuring Volatile Emissions From Moss Gametophytes: A Review Of Methodologies And New Applications, Danlyn L. Brennan, Leslie M. Kollar, Scott Kiel, Timea Deakova, Aurélie Laguerre, Stuart F. Mcdaniel, Sarah Eppley, Elliott T. Gall, Todd Rosenstiel

Center for Life in Extreme Environments Publications

Mosses inhabit nearly all terrestrial ecosystems and engage in important interactions with nitrogen-fixing microbes, sperm-dispersing arthropods, and other plants. It is hypothesized that these interactions could be mediated by biogenic volatile organic compounds (BVOCs). Moss BVOCs may play fundamental roles in influencing local ecologies, such as biosphere–atmosphere–hydrosphere communications, physiological and evolutionary dynamics, plant–microbe interactions, and gametophyte stress physiology. Further progress in quantifying the composition, magnitude, and variability of moss BVOC emissions, and their response to environmental drivers and metabolic requirements, is limited by methodological and analytical challenges. We review several sampling techniques with various analytical approaches and describe best practices …

Mass Capacity Analysis Of Stormwater Control Measures Using Synthetic Stormwater With Silica, Organic And Hydrocarbon Constituents, Craig Michael Fairbaugh

Dissertations and Theses

Stormwater control measure (SCM) performance is well studied regarding solids removal; however, analysis of mass loading capacity, long-term performance, and maintenance demands are challenging due to the variability and multiple constituents inherent in urban stormwater. This research examines the long-term water quality performance and sediment mass capacity of two common SCMs: high rate biofiltration (HRBF) and conventional bioretention (BRT). Pollutant removal trials were conducted in a laboratory setting per the New Jersey Department of Environmental Protection (NJDEP) filtration protocol in two phases: the first using inorganic sediment per the NJDEP protocol, the second phase with the addition of organic sediment …

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 …

Modeling Cyanobacteria Vertical Migration, Corina Christina Mae Overman, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Cyanobacteria often cause harmful algal blooms and release toxic substances that can harm humans and animals. Accurately modeling these phytoplankton is a step towards predicting, preventing, and controlling such blooms. Certain cyanobacteria species are known to migrate vertically in the water column on a daily cycle. Capturing this behavior is one aspect of modeling their dynamics. Previous studies on modeling cyanobacterial vertical migration are reviewed and summarized. Several models of cyanobacteria vertical movement are tested using data from field studies. These models are applied using both continuum and particle-tracking frameworks. Models range in complexity from simple functions of time to …

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 …

Effects Of Long Duration Earthquakes On The Interaction Of Inertial And Liquefaction-Induced Kinematic Demands On Pile-Supported Wharves, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Nason Mccullough, Scott Schlechter

Civil and Environmental Engineering Faculty Publications and Presentations

Nonlinear dynamic analyses were performed to evaluate the effects of ground motion duration on the dynamic response of a pile-supported wharf subjected to liquefaction-induced lateral ground deformations. The numerical model was first calibrated using recorded data from a well-instrumented centrifuge test, after which incremental dynamic analyses were conducted using a suite of spectrally matched motions with different durations. The nonlinear dynamic analyses were performed to evaluated three loading scenarios: combined effects of inertial loads from the wharf deck and kinematic loads from ground deformations, deck inertial loads only in the absence of liquefaction (with minimal kinematic loads), and kinematic loads …

A Self-Referencing Non-Destructive Test Method To Detect Damage In Reinforced Concrete Bridge Decks Using Nonlinear Vibration Response Characteristics, Ali Hafiz, Thomas Schumacher, Anis M. Raad

Civil and Environmental Engineering Faculty Publications and Presentations

Several non-destructive test (NDT) methods, namely visual inspection, hammer sounding, chain drag, impulse response testing, impact echo testing, ultrasonic (array) echo testing, and under certain conditions ground penetrating radar (GPR) are currently used to detect and estimate the extent of damage such as delaminations in reinforced concrete bridge decks. In this article, we present a self-referencing NDT method that builds on impulse response (IR) testing to detect damage using nonlinear vibration characteristics. The hypothesis is that for an undamaged deck, varying the impact force applied to a specific test point does not affect the corresponding frequency response function (FRF) for …

The Impact Of New Light Rail Service On Employment Growth In Portland, Oregon, Lahar Santra

Dissertations and Theses

This study quantitatively examines the impact of the new Light Rail Transit (LRT) service on employment growth in retail, knowledge, and service sectors before and after opening the LRT. At the corridor level, this study conducts a case study of Greenline in Southeast Portland, Oregon. The results of the corridor level study suggest that the new LRT service increased employment along the Greenline corridor among all the three sectors of interest- retail, knowledge, service in the long-term (ten years) while having slightly different results for the short-term (five years), likely due to the slow growth of LRT benefits. This study …

Evaluation Of Posted Speed Limits Reductions On Urban Roads With A High Percentage Of Cyclists, Jaclyn S. Schaefer, Miguel Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents a before and after analysis of the impact of posted speed limit (PSL) changes on passenger car (FHWA class two vehicles) speeds in Portland, OR. The study focuses on urban roads, comparing sites that underwent a PSL 5-mph reduction (treatment sites) and sites where the PSL did not change (control sites). Sites with a high percentage of and priority for cyclists (neighborhood greenways) and sites with a more standard traffic composition were compared. Differences in speed characteristics such as mean and 85th percentile speeds, the speed variance, and the proportion of vehicles exceeding a speed threshold (relative …

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 …

Compound Flooding In Convergent Estuaries: Insights From An Analytical Model, Ramin Familkhalili, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

We investigate here the effects of geometric properties (channel depth and cross-sectional convergence length), storm surge characteristics, friction, and river flow on the spatial and temporal variability of compound flooding along an idealized, meso-tidal coastal-plain estuary. An analytical model is developed that includes exponentially convergent geometry, tidal forcing, constant river flow, and a representation of storm surge as a combination of two sinusoidal waves. Nonlinear bed friction is treated using Chebyshev polynomials and trigonometric functions, and a multisegment approach is used to increase accuracy. Model results show that river discharge increases the damping of surge amplitudes in an estuary, while …

A Pipeline For Enhanced Multimodal 2d Imaging Of Concrete Structures, Sina Mehdinia, Thomas Schumacher, Xubo Song, Eric A. Wan

Civil and Environmental Engineering Faculty Publications and Presentations

We present an imaging pipeline to achieve enhanced images of the interior of concrete from ground penetrating radar (GPR) and ultrasonic echo array (UEA) measurements. This work lays the foundation for an advanced yet practical imaging tool to assess concrete structures. Specifically, we propose an enhanced two-dimensional (2D) total focusing method (XTFM) to reconstruct images from raw GPR and UEA data. The proposed XTFM algorithm integrates total focusing method (TFM) and synthetic aperture focusing technique (SAFT) concepts to post-process large independent and interelement measurements from both modalities in a computationally efficient way. Furthermore, we introduce a novel 2D image fusion …

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 …

Improving Bicycle Crossings At Unsignalized Intersections Through Pavement Markings: Analysis Of The City Of Portland Innovative Strategy, Frank Boateng Appiah

Dissertations and Theses

The increasing trend in the number of bicycle crashes in the U.S since 2009 has been a major challenge to safety. In 2019, a total of 36,096 people were killed on U.S roadways. A total of 846 (2.3%) of these fatalities were bicyclists and around 75% of the bicycle fatalities occur in urban areas and intersections are common locations of crashes. Many bicycle enhancements such as bike boxes, bicycle signals, curb extensions have been installed to improve safety at signalized intersections. The City of Portland OR experimented with an innovative treatment to improve bicycle crossings at unsignalized crossings. This treatment, …

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 …

Exploring How Antecedent Precipitation Amount And The Effects Of Covid-19 Affect Stormwater Runoff Quality Along Urban Gradients, Daniel Ramirez, Katherine Gelsey

REU Final Reports

Stormwater runoff quality is affected by a multitude of factors including surrounding land characteristics, human activities, and antecedent precipitation amounts. We explore how seasonal and variable precipitation affect E. Coli, total suspended solids, nitrogen-nitrate, orthophosphate, lead, and zinc concentrations in Portland, OR, USA. Correlation analysis was conducted between the pollutant concentrations and antecedent rainfall each sample site received for the previous 1, 3, 5, 7, and 30 days from when the sample was taken. We ran Mann-Whitney tests to determine if the levels of the pollutants were statistically different between the wet season and the dry season. We found that …

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 …

Assessing The Impact Of Changing Drought Conditions On Wildfire Emissions In Washington And Oregon, Maggie Liu

altREU Projects

Wildfires impact public health, and threaten life, livelihood, and property across the United States, particularly on the West Coast. This project seeks to find correlations between drought and wildfire emissions by comparing the Modified Palmer Drought Index (PMDI) with smoke particulate (PM2.5) emissions from fires in Oregon and Washington. PM2.5 emissions were taken from 2002 – 2020 from the National Center for Atmospheric Research’s FINN model, which uses satellite observations of active fires to assign burned area, and compares against observed vegetation to model emissions. This project found the strongest positive correlation between fire activity for a summer season (July …

Finding Lonely Routes For Runners And Bikers, Ethan T. Spicher

REU Final Reports

With COVID-19 raging around the world, personal health is even more important to a lot of people. One way to maintain good physical and mental health is to exercise according to Deslandes [2]. When exercising it may be important to make sure that you are running/biking on trails that are less populated than others, as well as taking into account the distance. This can be solved by creating an algorithm that allows the user to choose the starting and end point, and the algorithm will then find the optimal path between the two points with the distance and popularity of …

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 …

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 …

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 …

Modeling Cyanotoxin Production, Fate And Transport In Surface Waterbodies, Bernadel Rose Hintz Garstecki

Dissertations and Theses

Cyanobacteria exist throughout the world and are frequently associated with forming toxic blooms. The toxins produced by cyanobacteria, cyanotoxins, are harmful to both humans and animals. Rising temperatures due to global climate change, increased nutrient loading, and other anthropogenic impacts on waterbodies are expected to increase the prevalence of cyanobacteria. It is vital that we protect our drinking water supplies and natural water resources. Modeling the production and movement of these toxins is an important step in limiting exposure to them and evaluating management strategies to mitigate their impact. Cyanotoxins are diverse and the conditions under which they are formed …

Differing Effects Of Four Building Materials On Viable Bacterial Communities And Vocs, Gwynne Á. Mhuireach, Leslie Dietz, Willem Griffiths, Patrick Finn Horve, Aurélie Laguerre, Dale Northcutt, Roo Vandegrift, Elliott T. Gall, Kevin Van Den Wymelenberg

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor environmental quality is a paramount concern among architects. Exposure to VOCs and microorganisms impacts occupant health, yet the role of materials on these exposures remains poorly understood. In this study, we placed four material types in individual microcosms to test whether material type influences bacterial community structure and VOC emission. We used culture-independent methods to characterize bacterial communities and TD-GC-MS to measure VOC emission. We found that viable bacterial communities had different patterns of abundance, diversity, and composition, in comparison with total (viable plus dead cells) bacterial communities. Examining viable bacteria only, Earth had the highest abundance and diversity, …

Comparing Instruments For Measuring Runoff From Experimental Ecoroof Platforms: A Case Study On Test Plots At Portland State University, Chance F. Hodges

University Honors Theses

Stormwater management is a primary ecological benefit ecoroofs provide to ecosystems. Quantification of runoff from large scale ecoroofs is difficult to replicate, so researchers often utilize smaller experimental ecoroof platforms. This approach is becoming increasingly common, so it is useful to compare and contrast approaches for runoff measurement at the platform scale. This paper uses the four 17.86 m² ecoroof platforms located on the Science Research and Teaching Center (SRTC) at Portland State University (PSU) in Portland, OR as a case study. A unique condition of these platforms is that they are installed at grade on the roof with …

Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?, Edgar Sanchez Fausto

University Honors Theses

Atmospheric rivers (ARs) play a crucial role in delivering precipitation worldwide. This makes them an important phenomenon for water resource specialists to study. One such interest is to understand what mechanisms make ARs produce significant rainfall and associated hazards such as flooding. One possible mechanism is that AR duration or intensity may increase when it interacts with a secondary cyclone, either of which can increase the AR category scale. The purpose of this study is to determine whether AR and secondary cyclone interactions increase the category scale ARs. Out of 52 AR events analyzed, 32 events contained at least one …

Adaptive Routing Behavior With Real-Time Information Under Multiple Travel Objectives, Ravi Venkatraman, Stephen D. Boyles, Rachel James, Avinash Unnikrishnan, Priyadarshan N. Patil

Civil and Environmental Engineering Faculty Publications and Presentations

Real-time information about traffic conditions is becoming widely available through various media and connected-vehicle technology. In such conditions, travelers have better knowledge about the system and adapt as the system evolves dynamically during their travel. Drivers may change routes during their travel in order to optimize their own objective of travel. Various travel objectives are captured in mathematical models via disutility functions. The focus of this research was to study the behavior of travelers with multiple trip objectives when they are provided real-time information, and assess their ability to determine “optimal” routing policies, compared to exact solutions based on the …