Civil and Environmental Engineering Commons^™

Time-Dependent Transportation Network Design Considering Construction Impact, Yi He, Ziqi Song, Lihui Zhang

Civil and Environmental Engineering Faculty Publications

A traditional discrete network design problem (DNDP) always assumes transportation infrastructure projects to be one-time events and ignores travelers’ delays caused by construction work. In fact, infrastructure construction usually lasts for a long time, and the impact on traffic can be substantial. In this paper, we introduce time dimension into the traditional DNDP to explicitly consider the impact of road construction and adopt an overtime policy to add flexibility to construction duration. We address the problem of selecting road-widening projects in an urban network, determining the optimal link capacity, and designing the schedule of the selected projects simultaneously. A time-dependent …

Safety Assessment And Risk Estimation For Unmanned Aerial Vehicles Operating In National Airspace System, Xuejun Zhang, Yang Liu, Yu Zhang, Xiangmin Guan, Daniel Delahaye, Li Tang

Civil and Environmental Engineering Faculty Publications

This paper proposes an effective approach for modelling and assessing the risks associated with unmanned aerial vehicles (UAVs) integrated into national airspace system (NAS). Two critical hazards with UAV operations are considered and analyzed, which are ground impacts and midair collisions. Threats to fatalities that result from the two hazards are the focus in the proposed method. In order to realize ground impact assessment, a multifactor risk model is designed by calculating system reliability required to meet a target level of safety for different UAV categories. Both fixed-wing and rotary-wing UAVs are taken into account under a real scenario that …

Oil Droplet Transport Under Non-Breaking Waves: An Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Roozbeh Golshan, Michel C. Boufadel, Victor A. Rodriguez, Xiaolong Geng, Feng Gao, Thomas King, Brian Robinson, Andres E. Tejada-Martinez

Civil and Environmental Engineering Faculty Publications

Oil droplet transport under a non-breaking deep water wave field is investigated herein using Computational Fluid dynamics (CFD). The Reynolds-averaged Navier–Stokes (RANS) equations were solved to simulate regular waves in the absence of wind stress, and the resulting water velocities agreed with Stokes theory for waves. The RANS velocity field was then used to predict the transport of buoyant particles representing oil droplets under the effect of non-locally generated turbulence. The RANS eddy viscosity exhibited an increase with depth until reaching a maximum at approximately a wave height below the mean water level. This was followed by a gradual decrease …

A Systems Analysis Of Factors Influencing Household Solar Pv Adoption In Santiago, Chile, Jeffrey Walters, Jessica Kaminsky, Lawrence Gottschamer

Civil and Environmental Engineering Faculty Publications

Societal uptake of household solar photovoltaic (PV) technology is the result of a complex and interdependent array of technical, social, political and economic factors. This novel study employs a systems lens to examine both technical and non-technical barriers to renewables, with a focus on interactions that are empirically influential on PV uptake. Using local solar expert stakeholder input into a participatory systems approach, this study provides a structural analysis of factors influencing household solar adoption. The approach is applied and assessed for household solar PV systems in Santiago, Chile, to gain insight into the interconnected factors driving technology adoption. Barriers …

The Utah Snow Load Study, Brennan Bean, Marc Maguire, Yan Sun

Civil and Environmental Engineering Faculty Publications

Recent reports of snow related building collapses across the western United States in early 2017 highlight the importance of snow load considerations in building design. Specifying such design snow loads requires a proper balance between safety and economy. As articulated by Nowak and Collins (2012): "Conceptually, we can design [a] structure to reduce the probability of failure, but increasing the safety...beyond a certain optimum level is not always economical." It is the search for this optimum level of safety that has motivated the development of design ground snow loads at state and local levels.

Modeling The Effect Of Gi Implementation In The Red Butte Creek Area: The Case For "Not All Gi Is Created Equal", Rosa A. Fernández Valasquez, Ryan Dupont

Civil and Environmental Engineering Faculty Publications

• Background on the Project
• Review of Work Evaluating Organic Matter Impacts from Stormwater Discharges to Jordan Using High Frequency Data
• Modeling Approach for Stormwater Runoff and Pollutant Loading in Intermountain Region
• Model Flow & Pollutant Load Calibration
• GI Implementation Results
• Implications

Comparing Methods Of Targeting Obesity Interventions In Populations: An Agent-Based Simulation, Rahmatollah Beheshti, Mehdi Jalalpour, Thomas A. Glass

Civil and Environmental Engineering Faculty Publications

Social networks as well as neighborhood environments have been shown to effect obesity-related behaviors including energy intake and physical activity. Accordingly, harnessing social networks to improve targeting of obesity interventions may be promising to the extent this leads to social multiplier effects and wider diffusion of intervention impact on populations. However, the literature evaluating network-based interventions has been inconsistent. Computational methods like agent-based models (ABM) provide researchers with tools to experiment in a simulated environment. We develop an ABM to compare conventional targeting methods (random selection, based on individual obesity risk, and vulnerable areas) with network-based targeting methods. We adapt …

Ncer Assistance Agreement Annual Progress Report For Grant #83582401 - Assessment Of Stormwater Harvesting Via Manage Aquifer Recharge (Mar) To Develop New Water Supplies In The Arid West: The Salt Lake Valley Example, Ryan Dupont, Joan E. Mclean, Richard C. Peralta, Sarah E. Null, Douglas B. Jackson-Smith

Civil and Environmental Engineering Faculty Publications

The aims of the original proposed project remain the same, that is, to test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially and environmentally acceptable, economically viable, and legally feasible option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources. The project is being carried out via three distinct but integrated components that include: 1) Monitoring of existing distributed MAR harvesting schemes involving a growing number of demonstration Green Infrastructure (GI) test sites; 2) Integrated stormwater/vadose zone/groundwater/ ecosystem services modeling; and …

Observed Drought Indices Show Increasing Divergence Across Europe, James H. Stagge, Daniel G. Kingston, Lena M. Tallaksen, David M. Hannah

Civil and Environmental Engineering Faculty Publications

Recent severe European droughts raise the vital question: are we already experiencing measurable changes in drought likelihood that agree with climate change projections? The plethora of drought definitions compounds this question, requiring instead that we ask: how have various types of drought changed, how do these changes compare with climate projections, and what are the causes of observed differences? To our knowledge, this study is the first to reveal a regional divergence in drought likelihood as measured by the two most prominent meteorological drought indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI) across Europe over the …

Green Vs. Gray Infrastructure Cost, Rosa A. Fernández Valasquez, Ryan Dupont

Civil and Environmental Engineering Faculty Publications

No abstract provided.

The Grey To Green Infrastructure Transition - An Historical Shift In The Modern Infrastructure Paradigm, Ryan Dupont

Civil and Environmental Engineering Faculty Publications

No abstract provided.

Spatial Scale Gap Filling Using An Unmanned Aerial System: A Statistical Downscaling Method For Applications In Precision Agriculture, Leila Hassan-Esfahani, Ardeshir M. Ebtehaj, Alfonso F. Torres-Rua, Mac Mckee

Civil and Environmental Engineering Faculty Publications

Applications of satellite-borne observations in precision agriculture (PA) are often limited due to the coarse spatial resolution of satellite imagery. This paper uses high-resolution airborne observations to increase the spatial resolution of satellite data for related applications in PA. A new variational downscaling scheme is presented that uses coincident aerial imagery products from “AggieAir”, an unmanned aerial system, to increase the spatial resolution of Landsat satellite data. This approach is primarily tested for downscaling individual band Landsat images that can be used to derive normalized difference vegetation index (NDVI) and surface soil moisture (SSM). Quantitative and qualitative results demonstrate promising …

Optimal Cultivation Pattern To Increase Revenue And Reduce Water Use: Application Of Linear Programming To Arjan Plain In Fars Province, Amin Daghighi, Ali Nahvi, Ungtae Kim

Civil and Environmental Engineering Faculty Publications

Because the available water resources of the Arjan plain region in Iran do not fully meet the watering requirements for plants in farmlands, the crops suffer from water stress, a situation that causes them to wilt. The aim of this study is to develop a water resources planning model that helps decision-makers determine an appropriate cultivation pattern, optimize the exploitation from surface water resources, and specify the method of allocating water across different farm crops to minimize the detrimental effects of water shortage. Through investigating various models of water resources planning and properties along with the governing conditions for each …

The Effects Of Chemical Coagulants On The Decolorization Of Dyes By Electrocoagulation Using Response Surface Methodology (Rsm), Erick B. Butler, Yung-Tse Hung, Oliver Mulamba

Civil and Environmental Engineering Faculty Publications

This study assessed the efficiency of electrocoagulation (ECF) coupled with an addition of chemical coagulant to decolorize textile dye. Tests were conducted using Box Behnken methodology to vary six parameters: dye type, weight, coagulant type, dose, initial pH and current density. The combination of electrocoagulation and chemical coagulation was able to decolorize dye up to 99.42 % in 30 min of treatment time which is remarkably shorter in comparison with using conventional chemical coagulation. High color removal was found to be contingent upon the dye type and current density, along with the interactions between the current density and the coagulant …

Designing And Implementing A Network For Sensing Water Quality And Hydrology Across Mountain To Urban Transitions, Amber Spackman Jones, Zachary T. Aanderud, Jeffery S. Horsburgh, David P. Eiriksson, Dylan Dastrup, Christopher Cox, Scott B. Jones, David R. Bowling, Jonathan Carlisle, Gregory T. Carling, Michelle A. Baker

Civil and Environmental Engineering Faculty Publications

Water resources are increasingly impacted by growing human populations, land use, and climate changes, and complex interactions among biophysical processes. In an effort to better understand these factors in semiarid northern Utah, United States, we created a real-time observatory consisting of sensors deployed at aquatic and terrestrial stations to monitor water quality, water inputs, and outputs along mountain to urban gradients. The Gradients Along Mountain to Urban Transitions (GAMUT) monitoring network spans three watersheds with similar climates and streams fed by mountain winter-derived precipitation, but that differ in urbanization level, land use, and biophysical characteristics. The aquatic monitoring stations in …

Long-Term Assessment Of Climate Change Impacts On Tennessee Valley Authority Reservoir Operations: Norris Dam, Joseph Rungee, Ungtae Kim

Civil and Environmental Engineering Faculty Publications

Norris Reservoir is the oldest and largest reservoir maintained and operated by the Tennessee Valley Authority (TVA). Norris Dam received a new operating guide in 2004; however, this new guide did not consider projected climate change. In an aging infrastructure, the necessity to assess the potential impacts of climate change on water resources planning and management is increasing. This study used a combined monthly hydrologic model and a general circulation model’s (GCM) outcome to project inflows for three future time spans: 2030s, 2050s, and 2070s. The current operating guide was then assessed and optimized using penalty-function-driven genetic algorithms to gain …

Stress-Based Topology Optimization Of Steel-Frame Structures Using Members With Standard Cross Sections: Gradient-Based Approach, Navid Changizi, Mehdi Jalalpour

Civil and Environmental Engineering Faculty Publications

This article presents a computationally efficient methodology for stress-based topology optimization of steel frame structures with cross-sectional properties that are mapped from I-beam sections of a design manual. To account for the natural variability of the data, this mapping is achieved via quantile regression to derive continuous relationships between cross-sectional area (the design variable) and other section properties. These relationships are used for deriving the gradient of structural performance, which allows using computationally efficient gradient-based optimization schemes. Three frame structures are designed using the proposed algorithm, the resulting designs are compared with traditional compliance-based topology optimization algorithms, and changes in …

Fatigue Crack Detection Using Unmanned Aerial Systems In Under-Bridge Inspection, Sattar Dorafshan, Marc Maguire, Nathan V. Hoffer, Calvin Coopmans

Civil and Environmental Engineering Faculty Publications

The applications of Unmanned Aerial Systems (UAS) for bridge inspection, with emphasis on under-bridge inspection and fatigue crack detection, were studied in this report. The potential benefits and challenges of using UAS for bridge inspection were identified through an extensive literature survey. The feasibility of using UAS for fatigue crack detection was studied by determining the minimum lighting, camera distance and environmental requirements for three UAS. The DJI Mavic UAS performed better than the others in both indoor and outdoor GPS-denied inspections. An in-service bridge in Ashton, Idaho was inspected using this UAS to find fatigue cracks. No fatigue crack, …

Mapping Annual Riparian Water Use Based On The Single-Satellite-Scene Approach, Kul Khand, Saleh Taghvaeian, Leila Hassan-Esfahani

Civil and Environmental Engineering Faculty Publications

The accurate estimation of water use by groundwater-dependent riparian vegetation is of great importance to sustainable water resource management in arid/semi-arid regions. Remote sensing methods can be effective in this regard, as they capture the inherent spatial variability in riparian ecosystems. The single-satellite-scene (SSS) method uses a derivation of the Normalized Difference Vegetation Index (NDVI) from a single space-borne image during the peak growing season and minimal ground-based meteorological data to estimate the annual riparian water use on a distributed basis. This method was applied to a riparian ecosystem dominated by tamarisk along a section of the lower Colorado River …

Walking Behavior Of Individuals With And Without Disabilities At Right-Angle Turning Facility, Nirdosh Gaire, Mohammad Sadra Sharifi, Keith M. Christensen, Anthony Chen, Ziqi Song

Civil and Environmental Engineering Faculty Publications

To accommodate the needs of pedestrians, urban designers need to carefully consider pedestrian walking behavior in different walking environments. Detailed studies of the walking behavior of pedestrians have been conducted and used for pedestrian simulation models. A right-angle turning facility (RATF) is found in many built environments. Hence the study of pedestrians' walking behavior in RATFs is important to build pedestrian simulation models. Previous studies have failed to address the walking behavior of individuals with visual and mobility disabilities even though they comprise a significant portion of the population in the United States. The purpose of this paper is to …

Reference Evapotranspiration From Coarse-Scale And Dynamically Downscaled Data In Complex Terrain: Sensitivity To Interpolation And Resolution, Courtenay Strong, Krishna B. Khatri, Adam K. Kochanski, Clayton S. Lewis, L. Niel Allen

Civil and Environmental Engineering Faculty Publications

The main objective of this study was to investigate whether dynamically downscaled high resolution (4-km) climate data from the Weather Research and Forecasting (WRF) model provide physically meaningful additional information for reference evapotranspiration (E) calculation compared to the recently published GridET framework that uses interpolation from coarser-scale simulations run at 32-km resolution. The analysis focuses on complex terrain of Utah in the western United States for years 1985–2010, and comparisons were made statewide with supplemental analyses specifically for regions with irrigated agriculture. E was calculated using the standardized equation and procedures proposed by the American Society of Civil Engineers from …

Design Of A Metadata Framework For The Environmental Models With An Example Hydrologic Application In Hydroshare, Mohamed M. Morsy, Jonathan L. Goodall, Anthony M. Castronova, Pabitra Dash, Venkatesh Merwade, Jeffrey M. Sadler, Mohammad Adnan Rajib, Jeffery S. Horsburgh, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

Environmental modelers rely on a variety of computational models to make predictions, test hypotheses, and address specific problems related to environmental science and natural resource management. Scientists and engineers must devote significant effort to preparing these computational models. While significant attention has been devoted to sharing and reusing environmental data, less attention has been devoted to sharing and reusing environmental models. A first step toward increasing environmental model sharing and reuse is to define a general metadata framework for models that is flexible and, therefore, applicable across the wide variety of models used by environmental modelers. This paper proposes a …

Oxidation Pond For Municipal Wastewater Treatment, Erick Butler, Yung-Tse Hung, Mohammed Suleiman Al Ahmad, Ruth Yu-Li Yeh, Robert Lian-Huey Lu, Yen-Pei Fu

Civil and Environmental Engineering Faculty Publications

This literature review examines process, design, and cost issues related to using oxidation ponds for wastewater treatment. Many of the topics have applications at either full scale or in isolation for laboratory analysis. Oxidation ponds have many advantages. The oxidation pond treatment process is natural, because it uses microorganisms such as bacteria and algae. This makes the method of treatment cost-effective in terms of its construction, maintenance, and energy requirements. Oxidation ponds are also productive, because it generates effluent that can be used for other applications. Finally, oxidation ponds can be considered a sustainable method for treatment of wastewater.

Potential Crop Evapotranspiration And Surface Evaporation Estimates Via A Gridded Weather Forcing Dataset, Clayton S. Lewis, L. Niel Allen

Civil and Environmental Engineering Faculty Publications

Absent local weather stations, a gridded weather dataset can provide information useful for water management in irrigated areas including potential crop evapotranspiration calculations. In estimating crop irrigation requirements and surface evaporation in Utah, United States of America, methodology and software were developed using the ASCE Standardized Penman-Monteith Reference Evapotranspiration equation with input climate drivers from the North American Land Data Assimilation System (NLDAS) gridded weather forcing dataset and a digital elevation model. A simple procedure was devised to correct bias in NLDAS relative humidity and air temperature data based on comparison to weather data from ground stations. Potential evapotranspiration was …

Impact Of Wastewater Strength And Photocatalyst Loading On Decolourization Of Acid Orange 7 By Co-Doped Tio2, Erick Butler, Oliver Mulamba, Yung Tse Hung, Ching Cheng Chen, Yen Pei Fu

Civil and Environmental Engineering Faculty Publications

© 2017, Chemical Publishing Co. All rights reserved. Heterogeneous photocatalysis has proved to be a successful method for the degradation of water pollutants. In this work, the photocatalytic decolourization of acid orange 7 was performed by cobalt-doped titanium dioxide (Co-doped TiO2). The Co-doped TiO2 was synthesized and characterized using X-ray diffraction, scanning electron microscopy, energy diffraction spectroscopy, UV-visible reflective dispersion spectroscopy and adsorption of nitrogen gas. The acid orange 7 was prepared as a synthetic textile wastewater at three initial concentrations (24, 34 and 44 mg/L) with three photocatalyst loadings (0.025 g, 0.050, 0.1 g/100 mL acid orange 7). Results …

Bayesian Nonparametric Model For Estimating Multistate Travel Time Distribution, Emmanuel Kidando, Ren Moses, Eren E. Ozguven, Thobias Sando

Civil and Environmental Engineering Faculty Publications

© 2017 Emmanuel Kidando et al. Multistate models, that is, models with more than two distributions, are preferred over single-state probability models in modeling the distribution of travel time. Literature review indicated that the finite multistate modeling of travel time using lognormal distribution is superior to other probability functions. In this study, we extend the finite multistate lognormal model of estimating the travel time distribution to unbounded lognormal distribution. In particular, a nonparametric Dirichlet Process Mixture Model (DPMM) with stick-breaking process representation was used. The strength of the DPMM is that it can choose the number of components dynamically as …

Numerical Analysis Of Heat-Curved I-Girders, Antoine Gergess, Rajan Sen

Civil and Environmental Engineering Faculty Publications

Heat curving is a practical and economical process used by steel fabricators for curving structural steel. In this method, the flange edges of a fabricated straight girder are asymmetrically heated to induce residual curvature on cooling. Available analytical methods for predicting the resulting residual stress, strain and curvature are complex and iterative because of the need to account for material and geometric non-linearity. This paper presents a single-step, non-iterative, numerical procedure for determining the effects of heat-curving on residual stress and strain based on a previously developed simplified analysis. Thermal equilibrium equations for idealized heating profiles are first recast in …

Air Transport Versus High-Speed Rail: An Overview And Research Agenda, Xiaoqian Sun, Yu Zhang, Sebastian Wandelt

Civil and Environmental Engineering Faculty Publications

The development of high-speed rail (HSR) services throughout the last decades has gradually blurred the concept of competition and cooperation with air transportation. There is a wide range of studies on this subject, with a particular focus on single lines or smaller regions. This article synthesizes and discusses recently published studies in this area, while aiming to identify commonalities and deviations among different regions throughout the world, covering services from Europe, Asia, and North America. Our meta-analysis reveals that the literature is highly controversial and the results vary substantially from one region to another, and a generalization is difficult, given …

Finding P-Hub Median Locations: An Empirical Study On Problems And Solution Techniques, Xiaoqian Sun, Weibin Dai, Yu Zhang, Sebastian Wandelt

Civil and Environmental Engineering Faculty Publications

Hub location problems have been studied by many researchers for almost 30 years, and, accordingly, various solution methods have been proposed. In this paper, we implement and evaluate several widely used methods for solving five standard hub location problems. To assess the scalability and solution qualities of these methods, three well-known datasets are used as case studies: Turkish Postal System, Australia Post, and Civil Aeronautics Board. Classical problems in small networks can be solved efficiently using CPLEX because of their low complexity. Genetic algorithms perform well for solving three types of single allocation problems, since the problem formulations can be …

Advances In Modelling Connected And Automated Vehicles, Xiaobo Qu, Xiaopeng Li, Meng Wang, Vinayak Dixit

Civil and Environmental Engineering Faculty Publications

No abstract provided.