Civil and Environmental Engineering Commons^™

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 …

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 …

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), …

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 …

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 …

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 …

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 …

Update To Methodology For Setting Speed Limits In Urban Areas: Spr 827, Miguel Figliozzi, Avinash Unnikrishnan, Jaclyn S. Schaefer

Civil and Environmental Engineering Faculty Publications and Presentations

Many cities in Oregon are requesting a comprehensive review of speed zoning guidelines and existing procedures for streets with high volumes of active travelers. The main goal of this research is to develop recommendations for alternate criteria for setting speed zones on roadways with a high percentage of active travelers. Literature pertaining to factors affecting operating speed, speed and safety, speed management, and current speed zone practices is reviewed. The selection of the site and performance criteria is discussed. Qualities and characteristics of the speed data utilized are given. Distinctions between neighborhood and non-neighborhood greenways are noted. A before and …

Online Survey Of Driver Comprehension Of The Flashing Yellow Arrow For Right-Turn Signal Indications, Sirisha Kothuri, Christopher Monsere, Hisham Jashami, David Hurwitz

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents the results of an online survey of licensed driver comprehension of the right-turn signal displays with a focus on the flashing yellow arrow (FYA) and also including the circular green and red and red arrow. Recruitment postcards were mailed to a random sample of 9,872 residents in Oregon. The online survey yielded 399 responses. The open-ended responses were coded for comprehension and analyzed. The results suggest that FYA for right turns is well understood by Oregon drivers despite its current novelty (only two locations at the time of the research). Importantly, survey respondents were more likely to …

Evidence From Urban Roads Without Bicycle Lanes On The Impact Of Bicycle Traffic On Passenger Car Travel Speeds, Jaclyn S. Schaefer, Miguel A. Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

A concern raised by some motorists in relation to the presence of bicycles on urban roads without bicycle lanes, discussed in part of the traffic literature, is that cyclists will slow down motorized vehicles and therefore create congestion. This research answers this question: do bicycles reduce passenger car travel speeds on urban roads without bicycle lanes? To answer this question, a detailed comparative analysis of the travel speeds of passenger car (class two vehicles) on lower volume urban roads without bicycle lanes is presented. Speed distributions, the mean, and the 50th and 85th percentile speeds for two scenarios were examined: …

User-Rated Comfort And Preference Of Separated Bike Lane Intersection Designs, Christopher Monsere, Nathan Mcneil, Rebecca Sanders

Civil and Environmental Engineering Faculty Publications and Presentations

Improved bicycle infrastructure has become increasingly common in the United States as cities seek to attract new riders, including the demographic who do not feel comfortable riding with motor vehicle traffic. A key tool in designing low-stress networks is the use of separated or protected bicycle lanes, and intersections are the critical links. This paper presents an analysis of the perceived level of comfort of current and potential bicyclists from 277 survey respondents who rated 26 first-person video clips of a bicyclist riding through mixing zones, lateral shifts, bend-in, bend-out, and protected intersection designs. A total of 7,166 ratings were …

Improved Denoising Of Structural Vibration Data Employing Bilateral Filtering, Ning Liu, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

With the continuous advancement of data acquisition and signal processing, sensors, and wireless communication, copious research work has been done using vibration response signals for structural damage detection. However, in actual projects, vibration signals are often subject to noise interference during acquisition and transmission, thereby reducing the accuracy of damage identification. In order to effectively remove the noise interference, bilateral filtering, a filtering method commonly used in the field of image processing for improving data signal-to-noise ratio was introduced. Based on the Gaussian filter, the method constructs a bilateral filtering kernel function by multiplying the spatial proximity Gaussian kernel function …

Performance Of Us Concrete Highway Bridge Decks Characterized By Random Parameters Binary Logistic Regression, Omar Ghonima, Jason C. Anderson, Thomas Schumacher, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

This study employs a random parameters binary logistic regression (LR) to characterize the impact of environmental and structural parameters on concrete highway bridge deck deterioration nationwide. Two specific gaps in the literature are addressed: (1) the use of a nationwide dataset for analysis, and (2) the implementation of a methodology to account for unobserved heterogeneity. A total of 3,262 bridge deck deterioration observations derived from the authors’ nationwide concrete highway bridge deck performance inventory (NCBDPI) database were used in this study. The deterioration rate (DR) was computed as the decrease in the concrete bridge deck condition rating ( …

Sea Level, Tidal, And River Flow Trends In The Lower Columbia River Estuary, 1853-Present, Stefan Talke, Andrew Mahedy, David A. Jay, Patrick Lau, Conrad Hilley, Amanda Hudson

Civil and Environmental Engineering Faculty Publications and Presentations

Few tidal records are available pre-1900 for the Pacific Ocean. We improve data coverage by recovering historical tabulations and digitizing analog tide rolls from Astoria, Oregon for 1853-1876. Nearly 13,500 overlapping images of tides from 1855-1870 were digitized at a 6 minute resolution using a line-finding algorithm. Available hourly and high/low tabulations were also digitized, as were nearby hourly records from 1933-1943. Uncertainty was assessed by evaluating manual staff measurements, historical documents, and leveling surveys. Results suggest that uncertainty in mean sea level varies from ± 0.07m (early 1850s) to ± 0.03m (1867-1876) and is driven primarily by datum and …

Analytical And Field Verification Of A 3d Hydrodynamic And Water Quality Numerical Scheme Based On The 2d Formulation In Ce-Qual-W2, Hussein Ali Mahdi Al-Zubaidi, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

A new 3D hydrodynamic model was developed to simulate water quality transport in surface waterbodies. The governing equations are the continuity equation, free surface equation, momentum equation and transport equation. The 2D numerical scheme of CE-QUAL-W2 was expanded in three dimensions and modified to solve for the free surface elevation. A time splitting technique was employed to solve the momentum and transport equation. The numerical formulation of the 3D scheme used a novel solution, which resulted in a tri-diagonal matrix form for solving the free surface equation rather than a more computationally intensive penta-diagonal matrix solution. In addition, the hydrodynamic …

A Study Of The Competitiveness Of Autonomous Delivery Vehicles In Urban Areas, Miguel A. Figliozzi, Dylan Jennings

Civil and Environmental Engineering Faculty Publications and Presentations

The rapid growth of e-commerce and package deliveries across the globe is demanding new solutions to meet customers’ desire for more and faster deliveries. This research focuses on the cost competitiveness of autonomous air and ground delivery vehicles. Three types of autonomous vehicle are analyzed: drones, sidewalk autonomous delivery robots (SADRs), and road autonomous delivery robots (RADRs). Autonomous vehicles are compared against a typical delivery van. The impact of capacity, range and time constraints are analyzed. Results show that each type of autonomous delivery vehicle is suitable in different scenarios and can therefore complement each other to reduce costs or …

A Study Of Road Autonomous Delivery Robots And Their Potential Impacts On Freight Efficiency And Travel, Dylan Jennings, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Road autonomous mobile robots have attracted the attention of delivery companies and policy makers for their potential to reduce costs and increase urban freight efficiency. Established delivery companies and new startups are investing in technologies that reduce delivery times and/or increase delivery drivers’ productivity. In this context, the adoption of Road Automatic (or Autonomous) Delivery Robots (RADRs) has a growing appeal. Several RADRs are currently being tested in the United States. The key novel contributions of this research are: (a) an analysis of the characteristics and regulation of RADRs in the US and (b) a study of the relative travel, …

Understanding Roundabout Safety Through The Application Of Advanced Econometric Techniques, Hamsa Abbas Zubaidi, Jason C. Anderson, Salvador Hernandez

Civil and Environmental Engineering Faculty Publications and Presentations

Intersections present a significant safety concern, as such in an effort to reduce the more serious injuries occurring at or near intersections, many jurisdictions have turned to implementing roundabouts. Despite the advantages that roundabouts provide, crashes still occur, and less severe crashes are on the rise. The study presented in this paper investigates a crash-based analysis to better understand the factors that may influence less severe crashes to those of more severe crashes given various roundabout configurations and crash types. Using Oregon’s crash database from 2011 to 2015 a series of log likelihood ratio tests were conducted to validate that …

Factors Affecting Injury Severity In Vehicle-Pedestrian Crashes: A Day-Of-Week Analysis Using Random Parameter Ordered Response Models And Artificial Neural Networks, Seyedmirsajad Mokhtarimousavi, Jason C. Anderson, Atorod Azizinamini, Mohammed Hadi

Civil and Environmental Engineering Faculty Publications and Presentations

The high number of vehicle–pedestrian crashes in the United State has gained increased attention among transportation safety analysts in recent years. Being directly exposed to the collision force makes pedestrians more prone to becoming severely injured when in crash than other road users. Considering the fact that pedestrian-involved crashes is a serious public health problem, the current study’s aim is to investigate the contributing factors associated with injury severity of pedestrian crashes by time-of-week. Separate injury severity models for weekday and weekend crashes were developed, and the overall stability of the model estimates was examined through likelihood ratio tests. For …

Carbon Emissions Reductions In Last Mile And Grocery Deliveries Utilizing Autonomous Vehicles, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

New driverless air and ground vehicles are being launched and tested to deliver products or services in the areas of retail, groceries, and healthcare. This research focuses on the efficiency of autonomous (driverless) delivery vehicles in terms of vehicle-miles, energy consumption, and carbon emissions. Drones or UAVs, sidewalk autonomous delivery robots (SADRs), and road autonomous delivery robots (RADRs) vehicles carbon emissions are compared against emissions from an electric van (e-van), a conventional internal combustion engine van, and driving to a store utilizing electric and conventional vehicles. The impacts of vehicle capacity, range, and time constraints are analyzed as well as …