Engineering Commons^™

Experimental Investigation On Short Concrete Columns Laterally Strengthened With Ferrocement And Cfrp, Wisam Amer Aules, Yasir Saeed, Hosam Abdullah Al-Azzawi, Franz Rad

Civil and Environmental Engineering Faculty Publications and Presentations

The use of ferrocement in strengthening reinforced concrete (RC) structures has increased recently. Ferrocement has mostly been used to provide extra confinement for RC columns. However, its performance, especially in combination with CFRP confinement has not yet been fully understood. In this study, a total of fifteen columns were experimentally tested to investigate the effects of using ferrocement confinement in strengthening square RC columns. The combination between CFRP and ferrocement in strengthening RC columns has also been investigated. In addition to providing extra confinement, ferrocement is used to modify the shape of square columns to curvilinear shape, which is more …

Systemic Opportunities To Improve Older Pedestrian Safety: Merging Crash Data Analysis And A Stakeholder Workshop, Jason C. Anderson, Sirisha Kothuri, Christopher M. Monsere, David S. Hurwitz

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents a framework for improving older pedestrian safety in regard to serious (fatal and incapacitating) crashes, using Oregon as a case study. On review of state and federal practices pertaining to older pedestrian safety, 4 years of crash data identified 112 older (≥ 65 years) pedestrian serious injury crashes. These data were explored for factors that might be addressed systemically using two methods. First, raw frequencies in the crash data were assessed to determine trends and crash-related factors that are overrepresented. Second, a random forest analysis was conducted to determine important variables for predicting older pedestrian serious injury …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

Measuring Pedestrian Level Of Stress In Urban Environments: Naturalistic Walking Pilot Study, Seth Lajeunesse, Paul Ryus, Wesley Kumfer, Sirisha Kothuri, Krista Nordback

Civil and Environmental Engineering Faculty Publications and Presentations

Walking is the most basic and sustainable mode of transportation, and many jurisdictions would like to see increased walking rates as a way of reducing congestion and emission levels and improving public health. In the United States, walking trips account for 10.5% of all trips undertaken. To increase this rate, additional research on what makes people feel more comfortable while walking is needed. Research on pedestrian quality of service (QOS) has sought to quantify the performance of the pedestrian facilities from a pedestrian’s perspective. However, the impact of pedestrian safety countermeasures on pedestrian QOS for roadway crossings is largely unknown. …

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. …

Evolving Tides Aggravate Nuisance Flooding Along The U.S. Coastline., Sida Li, Thomas Wahl, Stefan A. Talke, David A. Jay, Philip M. Orton, Xinghui Liang, Guocheng Wang, Lintao Liu

Civil and Environmental Engineering Faculty Publications and Presentations

Nuisance flooding (NF) is defined as minor, nondestructive flooding that causes substantial, accumulating socioeconomic impacts to coastal communities. While sea-level rise is the main driver for the observed increase in NF events in the United States, we show here that secular changes in tides also contribute. An analysis of 40 tidal gauge records from U.S. coasts finds that, at 18 locations, NF increased due to tidal amplification, while decreases in tidal range suppressed NF at 11 locations. Estuaries show the largest changes in NF attributable to tide changes, and these can often be traced to anthropogenic alterations. Limited long-term measurements …

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. …

Accuracy Assessment Of Global Internal-Tide Models Using Satellite Altimetry, Loren Carrere, Brian K. Arbic, Brian Dushaw, Gary D. Egbert, Svetlana Erofeeva, Florent Lyard, Richard D. Ray, Clément Ubelmann, Edward Zaron, Zhongxiang Zhao, Jay F. Shriver, Maarten C. Buijsman, Nicolas Picot

Civil and Environmental Engineering Faculty Publications and Presentations

Altimeter measurements are corrected for several geophysical parameters in order to access ocean signals of interest, like mesoscale or sub-mesoscale variability. The ocean tide is one of the most critical corrections due to the amplitude of the tidal elevations and to the aliasing phenomena of high-frequency signals into the lower-frequency band, but the internal-tide signatures at the ocean surface are not yet corrected globally.

Internal tides can have a signature of several centimeters at the surface with wavelengths of about 50–250 km for the first mode and even smaller scales for higher-order modes. The goals of the upcoming Surface Water …

Implementation Of A Novel Inertial Mass System And Comparison To Existing Mass-Rig Systems For Shake Table Experiments, Alvaro Lopez, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Shake table testing is one of the more effective experimental approaches used to study and evaluate seismic performance of structures. Reduced-scale models can still result in large-scale specimens where incorporating the required inertial mass effectively and safely can be challenging. This study proposes a new system of arranging the mass in the experiments that combines the realism of mass participation during earthquake excitation when supported by the shake table with laboratory practicality considerations of the mass positioned off the specimen. The characteristics and dynamic motion equations for the proposed system are described and applied to shake table experiments involving large-scale …

Exploring The Impact Of Socio-Demographic Characteristics, Health Concerns, And Product Type On Home Delivery Rates And Expenditures During A Strict Covid-19 Lockdown Period: A Case Study From Portland, Or, Miguel Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

E-commerce volumes and home deliveries have experienced steady growth in the last two decades. Strict COVID-19 lockdowns made home delivery an essential service and a lifeline for many households that, for travel restrictions or health concerns, were not able to utilize traditional shopping methods. This research studies the impact of socio-demographic variables and e-commerce attitudes on household deliveries for seven product categories (groceries, meals, electronics, household and office goods, recreational items, and fashion, beauty and personal care products, and medicine/health-related products) during the lockdown period in the greater Portland metropolitan region. To understand these impacts, exploratory factor analysis and …

High-Temperature Performance Of Ambient-Cured Alkali- Activated Binder Concrete, Kruthi Kiran Ramagiri, Darshan Chauhan, Shashank Gupta, Arkamitra Kar, Dibyendu Adak, Abhijit Mukherjee

Civil and Environmental Engineering Faculty Publications and Presentations

Owing to their lower carbon footprint and efficient performance compared to portland cement (PC), alkali-activated binders (AAB) show promising potential as an alternative to PC. The present paper investigates the high-temperature performance of AAB concrete through compressive and bond strength tests. Four different AAB concrete mixes with varying proportions of fly ash: slag (100:0, 70:30, 60:40, and 50:50) cured under ambient conditions are exposed to elevated temperatures. The mechanical performance of AAB concrete is corroborated with microstructural changes. The results show that AAB concrete with fly ash: slag ratio of 70:30 exhibits the best mechanical performance after exposure to elevated …

'Menthol-Plus’: A Major Category Of Cigarette Found Among ‘Concept’ Descriptor Cigarettes From Mexico, James F. Pankow, Wentai Luo, Kevin J. Mcwhirter, Samantha M. Gillette, Joanna E. Cohen

Civil and Environmental Engineering Faculty Publications and Presentations

Background Tobacco companies are offering cigarettes with ‘concept’ descriptor names that suggest sensation and/or flavour properties (eg, Marlboro ‘Velvet Fusion’). Little has been known about the identities and levels of flavour chemicals in such cigarettes.

Methods Thirty-three filter cigarette variants from 27 packs (including two sampler packs with four variations each) from Canada and Mexico were analysed (rod + filter) for 177 flavour chemicals plus triacetin, a filter plasticiser and possible flavourant. Five brands of US mentholated filter cigarettes were also analysed.

Results Twenty-seven of the 33 cigarettes (all were Mexican variants) were categorised as ‘menthol-plus’: significant menthol (3.0–11.9 mg/cigarette), …

Spatial Accessibility And Equity Analysis Of Amazon Parcel Lockers Facilities, Jaclyn S. Schaefer, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

The onset of the COVID-19 pandemic has accelerated the growth of e-commerce and home 32 deliveries. Automated parcel lockers are a way to improve delivery efficiency, but despite their 33 rapid growth, little is known about their accessibility and equity impacts. Among e-commerce 34 players in the U.S., Amazon stands out by its large market share. This research studies the 35 location of Amazon lockers in Portland, Oregon utilizing highway, land use, employment, and 36 sociodemographic datasets. Geographical tools and cluster analysis are utilized to estimate 37 accessibility and equity metrics. Lockers tend to be located in mixed-use areas and …

Robust Maximum Coverage Facility Location Problem With Drones Considering Uncertainties In Battery Availability And Consumption, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

Given a set of spatially distributed demand for a specific commodity, potential facility locations, and drones, an agency is tasked with locating a prespecified number of facilities and assigning drones to them to serve the demand while respecting drone range constraints. The agency seeks to maximize the demand served while considering uncertainties in initial battery availability and battery consumption. The facilities have a limited supply of the commodity being distributed and also act as a launching site for drones. Drones undertake one-to-one trips (from located facility to demand location and back) until their available battery energy is exhausted. This paper …

Tensile Behavior Of Frp Anchors Made From Cfrp Ropes Epoxy-Bonded To Uncracked Concrete For Flexural Strengthening Of Rc Column, Yasir Saeed, Wisam Amer Aules, Franz N. Rad, Anis M. Raad

Civil and Environmental Engineering Faculty Publications and Presentations

One of the major problems with using fiber reinforced polymer (FRP) in strengthening reinforced concrete (RC) structures is FRP premature debonding. Anchoring FRP materials to concrete has become associated with most of the strengthening techniques. One of the anchoring techniques is using handmade anchors made from FRP materials. In previous studies, most FRP anchors were made from rolling pre-cut FRP sheets and had short embedment (mm) as they were used for flexural or shear strengthening of RC beams. In the present study, FRP anchors were made from carbon fiber reinforced polymer (CFRP) ropes and had long embedment to be used …