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2014

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Articles 61 - 90 of 735

Full-Text Articles in Civil Engineering

Computer Aided Water Management And Control - Colorado State University, John Labadie Oct 2014

Computer Aided Water Management And Control - Colorado State University, John Labadie

All ECSTATIC Materials

Present modern computer-aided tools of systems analysis to planning, design, and operation of water resource systems. Topics covered include: optimal operation of multipurpose reservoir systems; optimal flood control system operations; coordinated unit commitment in hydropower systems; optimal multicrop allocation of seasonal and intraseasonal irrigation water; risk-based design of stochastic reservoir operating policies; economic evaluation of integrated design of water storage and conveyance systems; optimal conjunctive use of surface water and groundwater; optimal reservoir operations for water quality management; and optimal investment timing and selection of water resource projects. Several case studies are presented for river basins in the U.S., Dominican …


Environmental Systems Analysis - Penn State, University Park, Douglas A. Haith Oct 2014

Environmental Systems Analysis - Penn State, University Park, Douglas A. Haith

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Undergraduate course in environmental systems analysis offered at Penn State, University Park in Fall 2014.


Environmental Engineering Systems, Mark Houck Oct 2014

Environmental Engineering Systems, Mark Houck

All ECSTATIC Materials

Introduces the concepts and applications of systems analysis in environmental engineering. Tools and methodologies of systems analysis are applied to improve the understanding and resolution of complex environmental engineering problems related to air, soil, and water quality and pollution. Scientific, engineering, political, social, legal, regulatory, medical, economic, and financial impacts of environmental engineering decisions are considered. Course taught at George Mason University.


Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad Oct 2014

Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad

Open Access Theses

The objective of this thesis was to investigate the factors that affect capacity-related driver behavior on modern roundabouts built on high-speed roads. The capacity of roundabouts is strongly affected by the behavior of drivers as represented by critical headway (critical gap) and follow-up headway (follow-up time). The effects of heavy vehicles (single-unit truck, bus, and semi-trailer) and area type (rural or urban) on roundabout capacity were investigated by comparing the critical headways for roundabouts located on high-speed and low-speed roads. The effects of nighttime conditions (in the presence of street lighting) were also considered. Data were collected using the Purdue …


Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss Oct 2014

Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss

Open Access Theses

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridges can be subject to protection because of the role they play in aesthetics. Unfortunately, original railings on historic bridges do not typically meet current crash-test requirements and typically do not meet current standards for railing height and size of permitted openings. The objective of this study is to develop strategies that can be used to address existing railings on historic bridges and to develop solutions …


Effective Cfrp Retrofitting Schemes For Prestressed Concrete Beams, Herish Abdullah Hussein Oct 2014

Effective Cfrp Retrofitting Schemes For Prestressed Concrete Beams, Herish Abdullah Hussein

Civil & Environmental Engineering Theses & Dissertations

This thesis presents a detailed theoretical study of a number of retrofitting schemes for prestressed concrete beams using carbon fiber reinforced polymer (CFRP) sheets to increase flexural strength and ductility. A simply-supported beam subjected to a gradually increasing uniformly distributed load is adopted for the study with a variety of CFRP retrofiring schemes. Three different types of beam cross sections are included for quantifying the influence of CFRP retrofitting when used in high compression regions in addition to CFRP use in high tension areas. To achieve this goal, nonlinear moment curvature relations are developed and coupled with a finite-difference solution …


Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok Oct 2014

Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok

Open Access Theses

Older reinforced concrete buildings can be prone to column shear and compression failures during earthquakes because of inadequate transverse reinforcement. Cities in seismic areas still have large inventories of older and potentially deficient buildings. To analyze every building and estimate its vulnerability in detail is costly. A simple method to rank quickly older buildings according to their seismic vulnerability is needed to help engineers prioritize the use of resources for rehabilitating the most vulnerable buildings.

Four indicators of building damage or collapse were evaluated using numerical analysis and prior data from building surveys: column index (Hassan & Sozen, 1997), R …


Evaluation Of Methods For Estimating Prestress Losses In High-Strength Structural Concrete, Mayren Yelitza Mata Carrillo Oct 2014

Evaluation Of Methods For Estimating Prestress Losses In High-Strength Structural Concrete, Mayren Yelitza Mata Carrillo

Open Access Theses

The purpose of this study was to evaluate the applicability of several current approaches used to estimate losses in prestressed concrete members with compressive strengths greater than 15ksi. The scope of the study focused on time-dependent losses for normal weight concrete bonded applications. The approaches evaluated were the PCI Design Handbook (2010) method, the AASHTO Specifications (2012) refined method, the PCI Bridge Design Manual (2003) time-dependent analysis using both the AASHTO (2012) and the PCI-BDM (2003) creep and shrinkage models, and a time-step method developed by Swartz (2010). The methods were compared to existing data on prestress losses from twenty-two …


Hydro-Climate Temporal Variations And Their Influences On Net Primary Production In A Eurasian Steppe Watershed, Xiaomin Yang Oct 2014

Hydro-Climate Temporal Variations And Their Influences On Net Primary Production In A Eurasian Steppe Watershed, Xiaomin Yang

Civil & Environmental Engineering Theses & Dissertations

Climate, which is the most important factor that influences Net Primary Productivity, has been detected changing all over the world. The confounding effects of step change invalidate the stationarity assumption of commonly used trend analysis methods such as the Mann-Kendall test technique, so previous studies have failed to explain inconsistencies between detected trends and observed large anomalies. In this research, by formulating a trend analysis approach that considers nonstationary due to step changes, trends and extreme occurrences of precipitation, temperature, and runoff in annual, seasonal, and monthly scales were analyzed in a mid-latitude Eurasian steppe watershed in northeast China, and …


Fire Behavior Of Bolted Connections, Qiaqia Zhu Oct 2014

Fire Behavior Of Bolted Connections, Qiaqia Zhu

Open Access Theses

Bolted connection failures have been observed in building fires and large-scale structural fire tests. Limited information is available on plate bearing behavior at elevated temperatures. The failure mode of a shear-tab connection could change from plate bearing failure to bolt shear failure between 400 (degree Celsius) °C to 600°C. Component-based models have been used to predict the behavior of bolted connections. Earlier researchers have developed simple mathematical models to represent the force-displacement relationships of bolt shear and plate bearing components of bolted connections. However, these models need to be verified experimentally for US building construction and materials. Therefore, eleven single-bolted …


A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek Oct 2014

A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek

Open Access Dissertations

Transportation project evaluation and prioritization use traditional performance measures including travel time, safety, user costs, economic efficiency, and environmental quality. The project impacts in terms of enhancing the infrastructure resilience or mitigating the consequences of infrastructure damage in the event of disaster occurrence are rarely considered in project evaluation. This dissertation presents a methodology to address this issue so that in evaluating and prioritizing investments, infrastructure with low security can receive the attention they deserve. Secondly, the methodology can be used for evaluating and prioritizing candidate investments dedicated specifically to security enhancement. In defining security as a function of threat …


Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai Oct 2014

Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai

Open Access Dissertations

Concrete-filled steel tube beam-columns are categorized as compact, noncompact or slender depending on the governing tube slenderness ratio. AISC 360-10 specifies the provisions for designing noncompact and slender rectangular and circular CFT members under axial compression, flexure, and combined axial and flexural loading. This research presents the development and evaluation of these design provisions. Available experimental databases of CFT members are reviewed, and a new experimental database of tests conducted on noncompact and slender CFT members is compiled. Detailed 3D finite element method (FEM) models are developed for noncompact and slender CFT members, and benchmarked using experimental results. The AISC …


Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang Oct 2014

Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang

Open Access Dissertations

Field evidence was interpreted to suggest that discontinuities in the longitudinal web reinforcement caused severe damage in structural walls during strong ground motion. To test this hypothesis, six small-scale reinforced concrete structural walls were tested under lateral displacement reversals. Test variables included the presence of web longitudinal reinforcement discontinuities and number of loading cycles. The test results indicated that unit tensile strains in longitudinal reinforcing bars in boundary elements were approximately 50% higher in structural walls with web longitudinal reinforcement cutoffs relative to walls without reinforcement cutoffs. Higher unit tensile strains caused an increase in permanent strain accumulation, increasing the …


Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao Oct 2014

Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao

Open Access Dissertations

One of the new engineering frontiers is the exploration of infrastructure materials with novel combinations of properties that break traditional paradigms. The goal of this study is to utilize two different nano-fibers, cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) to modify the nanoscale structures of cement composites and thereby improve the performance at the macro-level. This study also evaluates the mechanism behind the modification, since fiber bridging, the most common reinforcing mechanism for fiber-reinforced composites, cannot be simply applied because CNCs are too short to bridge cracks in cement composites. ^ The mechanical tests show an increase in the flexural …


Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn Oct 2014

Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn

Open Access Dissertations

The natural environment has been significantly affected by anthropogenic activities. Between 1700s and 2000s, agricultural land area had quintupled and the extent of natural vegetation was globally reduced by half. Furthermore many scientists argue that the recent rise in CO2 levels in the atmosphere is mainly due to anthropogenic activities. Anthropogenic activities may also play a crucial role in the change of the hydro-climatologic variables. In this study, impact of anthropogenic activities on two representative hydro-climatologic variables, temperature and streamflow, is investigated. The variations in temperature occur over larger spatial and time scale, and hence the United States is adopted …


A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh Oct 2014

A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh

Open Access Dissertations

Finite element simulations of contact problems often involve modeling the interaction of multiple bodies across a non-confirming interface. Non-Confirming Meshes (NCM) are typically associated with large sliding or adaptive refinement on one side of the interface to capture localized nonlinear behavior due to large deformations, damage and inelasticity. The use of NCMs, however, presents a number of numerical issues; the main challenge with such discretizations is to ensure compatibility of the kinematic and traction fields along the non-conforming interface. ^ The Enriched Discontinuous Galerkin Approach (EDGA) (Haikal and Hjelmstad,2010)addresses this challenge by implementing a local enrichment along with an interface …


Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz Oct 2014

Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz

Open Access Dissertations

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61\% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation …


Practitioner Interview, Kirk Westphal Sep 2014

Practitioner Interview, Kirk Westphal

All ECSTATIC Materials

Phone interview with Kirk Westphal from CDM Smith by Emily Berglund and David Watkins, Jr.. Interview questions asked inquired about (i) practitioner’s professional background, (ii) practitioner’s personal experience with systems analysis techniques and software in their job, (iii) role, benefits, and challenges in using systems analysis concepts in the water resources engineering profession, and (iv) recommendations for improving education of environmental and water resources systems analysis in universities.


2014 Fall Engr333 Project Assignment, Matthew K. Heun Sep 2014

2014 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Fall 2014 ENGR333 project focused on net zero homes.

I asked the students “What would it take for a home in Grand Rapids to become net-zero?”

Customer

The customers for this project were several homeowners in the Grand Rapids area.


Corrosion Resistance Of A Sand Particle-Modified Enamel Coating Applied To Smooth Steel Bars, Fujian Tang, Genda Chen, Richard K. Brow, Michael L. Koenigstein Sep 2014

Corrosion Resistance Of A Sand Particle-Modified Enamel Coating Applied To Smooth Steel Bars, Fujian Tang, Genda Chen, Richard K. Brow, Michael L. Koenigstein

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The protective performance of a sand particle-modified enamel coating on reinforcing steel bars was evaluated in 3.5 wt% NaCl solution by electrochemical impedance spectroscopy (EIS). Seven percentages of sand particles by weight were investigated: 0%, 5%, 10%, 20%, 30%, 50% and 70%. The phase composition of the enamel coating and sand particles were determined with the X-ray diffraction (XRD) technique. The surface and cross-sectional morphologies of the sand particle-modified enamel coating were characterized using scanning electron microscopy (SEM). XRD tests revealed three phases of sand particles: SiO2, CaCO3 and MgCO3. SEM images demonstrated that the …


Bs News September/October Sep 2014

Bs News September/October

Building Services Engineering

No abstract provided.


Impacts Of Climate Change On The Seasonality Of Extremes In The Columbia River Basin, Mehmet Demirel, Hamid Moradkhani Sep 2014

Impacts Of Climate Change On The Seasonality Of Extremes In The Columbia River Basin, Mehmet Demirel, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The impacts of climate change on the seasonality of extremes i.e. both high and low flows in the Columbia River basin were analyzed using three seasonality indices, namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and weighted persistence (WP). These indices reflect the streamflow regime, timing and variability in timing of extreme events respectively. The three indices were estimated from: (1) observed streamflow; (2) simulated streamflow by the VIC model using simulated inputs from ten combinations of bias corrected and downscaled CMIP5 inputs for the current climate (1979–2005); (3) simulated streamflow using simulated inputs from ten combinations of …


The Effect Of Multi-Model Averaging Of Climate Model Outputs On The Seasonality Of Rainfall Over The Columbia River Basin, Mehmet Demirel, Arun Rana, Hamid Moradkhani Sep 2014

The Effect Of Multi-Model Averaging Of Climate Model Outputs On The Seasonality Of Rainfall Over The Columbia River Basin, Mehmet Demirel, Arun Rana, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The rainfall seasonality index is the measure of precipitation distribution throughout the seasonal cycle. The aim of this study is to compare the effect of different multi-model averaging methods on the rainfall seasonality index at each 1/16 latitude-longitude cells covering the Columbia River Basin. In accordance with the same, ten different climate model outputs are selected from 45 available climate models from CMIP5 dataset. The reanalysis precipitation data is used to estimate the errors in rainfall seasonality for the climate model outputs. The inverse variance method and statistical multi criteria analysis (SMCA) method were used to estimate the weights for …


Development Of Simulation-Based Fragility Relationships For The Seismic Risk Assessment Of Buildings, Anas Salem (Mohammad Ghaleb) Issa Sep 2014

Development Of Simulation-Based Fragility Relationships For The Seismic Risk Assessment Of Buildings, Anas Salem (Mohammad Ghaleb) Issa

Theses

A number of driving engines are required for earthquake loss estimation and mitigation, including an inventory of exposed systems, seismic hazards of the study area and fragility relationships. The number of existing buildings in the UAE that may be at risk because of insufficient seismic design provisions cannot be underestimated. A crucial role in the recovery period following an earthquake is also played by emergency facilities. Therefore, a systematic seismic vulnerability assessment of a diverse range of reference structures representing pre-seismic code buildings and emergency facilities, in a highly populated and seismically active area in the UAE, has been conducted …


Instrumentation To Monitor Bridge Foundation On The Crosstown Project, Brian Welch Aug 2014

Instrumentation To Monitor Bridge Foundation On The Crosstown Project, Brian Welch

Journal of Undergraduate Research at Minnesota State University, Mankato

The Crosstown Bridge Monitoring Project is located at the intersection of Highway 62 and Interstate I35W a few miles south and west of downtown Minneapolis. The bridge being evaluated is at a railroad overpass located midway along the Crosstown expansion. This research project involved placing instrumentation on the bridge foundation in order to measure the change in the foundation loading during the course of the construction project. For several years there have been questions pertaining to the forces in the pile foundations that support highway embankments. This project placed strain gages on the pile foundations in order to monitor these …


Turbulent Circular Culvert Flow: Implications To Fish Passage Design, Amin Mohebbi Aug 2014

Turbulent Circular Culvert Flow: Implications To Fish Passage Design, Amin Mohebbi

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Culverts are popular conveyance structures in America and Canada to be used as a fish passage or in sewage collection and disposal systems. Fish passage design criteria is based on biological capabilities of fish whereas it should satisfy hydraulic and hydrological constraints as well. Failing to provide enough low velocity regions for aquatic organisms may result in their mass extinctions. Currently, proper road crossing design depends on either model studies or numerical simulations via Computational Fluid Dynamic (CFD) packages, both of which are expensive and time consuming. Further, although the design procedures released by FHWA recently ensures safe fish migration …


Comparison Of The Accuracy Of Traffic Counting Devices, Rodrigo Netto De Souza, Laura Slusher ,P.E. Aug 2014

Comparison Of The Accuracy Of Traffic Counting Devices, Rodrigo Netto De Souza, Laura Slusher ,P.E.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Traffic counting devices are commonly used by governmental agencies and private companies in order to assess traffic patterns and the level of occupancy of roadway networks. The data provided by these devices normally encompasses traffic volumes, vehicle classes and vehicle speeds, and are used by traffic engineers in the planning, design and operations of transportation systems. An evaluation of the accuracy of these devices is of great importance because traffic management decisions are compromised without qualified data. This research evaluated the performance of two different models of traffic counters, Jamar Technologies’ Radar Recorder and Vaisala’s Traffic Analyzer NC-200, both commonly …


A Wind-Derived Upwelling Index For Lake Michigan, Stephen B. Davis, Rebecca Essig, Cary Troy Aug 2014

A Wind-Derived Upwelling Index For Lake Michigan, Stephen B. Davis, Rebecca Essig, Cary Troy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Coastal upwelling is a phenomenon that occurs along coastlines throughout the world, and has been shown to be strongly correlated with large fish populations in these areas. Coastal upwelling occurs when strong coastal winds drive water transport away from the coast, causing colder, often nutrient-rich water to upwell in its place. While coastal upwellings can be detected with satellite imagery or in situ temperature measurements, these datasets are neither continuous nor long-term. A wind-derived upwelling index was created for Lake Michigan to continuously quantify upwellings over multiple decades, and to allow for further understanding of the impact of upwelling in …


The Influence Of Lightweight Aggregate On Internal Curing And Its Impact On Autogenous Shrinkage Of High-Performance Concrete, Neil J. Hartman, Timothy J. Barrett, Jason Weiss Aug 2014

The Influence Of Lightweight Aggregate On Internal Curing And Its Impact On Autogenous Shrinkage Of High-Performance Concrete, Neil J. Hartman, Timothy J. Barrett, Jason Weiss

The Summer Undergraduate Research Fellowship (SURF) Symposium

In bridge deck construction high performance concrete is often desirable, however in practice it is generally susceptible to early-age shrinkage cracking resulting in an overall reduction in service life. This research seeks to assess the potential for reducing early-age shrinkage in new bridge deck construction through the use of internal curing, a process in which internal reservoirs supply water to the hydrating cement paste during the early stages of cement hydration. In North America, internal curing is typically achieved by replacing a portion of the normal fine aggregate with an expanded fine lightweight aggregate (LWA). For this study, the free …


Roundabout Maintenance Manual, Emily A. Bonini, Pat Conner P.E., John Haddock Phd, P.E., Yu Tian Aug 2014

Roundabout Maintenance Manual, Emily A. Bonini, Pat Conner P.E., John Haddock Phd, P.E., Yu Tian

The Summer Undergraduate Research Fellowship (SURF) Symposium

In recent years, roundabouts have been rapidly growing in popularity. As a result, many communities are installing them in their roadways; however, they are encountering difficulties in maintaining them. Uneducated workers can cause damage to roundabouts and to themselves, costing cities time and money. This project aims to create a guide for communities new to roundabouts in order to reduce damages and unnecessary maintenance costs. Data was gathered by determining the most common maintenance questions and problems along with what information was already available on roundabout maintenance. Next, agencies most experienced with roundabouts were surveyed on the best maintenance practices. …