Civil and Environmental Engineering Commons^™

Low-Density Static Granular Media Filter Bed Turbidity Removal Model, Matthew Louque

LSU Master's Theses

The scattering of light within a fluid, referred to as its turbidity, was investigated against the presence of suspended solids. A linear regression analysis was conduced against turbidity and the total count, combined surface area, and combined volume of the suspended particles for various surface water sources (lakes, rivers, indoor aquaculture systems). It was found that the total combined surface area of suspended particles had the best linear correlation to turbidity, with an adjusted R² of 81.79%. This correlation was integrated with a current theoretical model for predicting solids removal across a granular bed to yield an Integrated Turbidity …

Long-Term Durability Of Frp Bond In The Midwest United States For Externally-Strengthened Bridge Components, Sasan Siavashi, Christopher D. Eamon, Abdel A. Makkawy, Hwai-Chung Wu

Civil and Environmental Engineering Faculty Research Publications

In this study, the bond strength of a typical FRP system subjected to long-term natural weathering in the Midwest United States is experimentally investigated, and the rate of degradation is estimated. To do this, the bond strength of an FRP system exposed to over fifteen years of weathering is determined with pull-off testing, and a relationship between strength reduction and exposure time is developed using regression analysis. For unweathered specimens, it was found that the attachment strength of the FRP system was governed by the concrete substrate, while for weathered specimens, the FRP system could detach by either a failure …

Failure Mode Identification Of Masonry Infilled Rc Frames, Rabab Allouzi, Ayhan Irfanoglu

Emirates Journal for Engineering Research

This paper presents a new method to identify the ultimate failure mode of reinforced concrete (RC) frames due to the presence of masonry infill walls. The proposed method is based on simple geometry, reinforcement ratios and material properties of the elements involved in the frame-wall assembly. A simple engineering tool, expressed in terms of infill wall-to-RC frame stiffness and strength ratios, is developed to estimate whether the ultimate failure mode that would evolve during strong earthquake ground shaking in the infilled RC frame is brittle or ductile. The brittle failure mode, that is, shear failure in columns, should be avoided …

Assessment Of Live Load Distribution Characteristics Of Press-Brake-Formed Tub Girder Superstructures, Guilherme Petty

Theses, Dissertations and Capstones

The scope of this thesis project was to refine the development of live load distribution factors for tub girders. This was done in three stages. First, experimental data was gathered to assess live load distribution on the Amish Sawmill Bridge located in Fairbank, Iowa. Then, finite element analysis models were developed to benchmark against experimental data. Finally, a series of parametric studies were performed to explore the distribution factors of steel tub girders under various design conditions and to generate more accurate live load distribution factors. Results drawn from this research project demonstrate that press-brake-formed steel tub girders exhibit consistent …

Lecture 1: Stochastic Hydrology, Julianne Quinn

All ECSTATIC Materials

This is the first lecture of CE 5500: Stochastic Hydrology, taught by Julianne Quinn at the University of Virginia.

Coupled Numerical Analysis Of Variations In The Capacity Of Driven Energy Piles In Clay, Arvin Farid, Daniel P. Zimmerman

Civil Engineering Faculty Publications and Presentations

Energy piles are an emerging alternative for the reduction of energy consumption to heat and cool buildings. Most of the research to date has focused on thermodynamic properties or axial and radial stress and strain of piles. This paper focuses on the effects of temperature fluctuation on the capacity of driven energy piles in clayey soils. Consolidation of clay surrounding driven piles affects the pile capacity (i.e., set up in clay). The heating and cooling periods of energy piles can create the excess pore-water pressure (EPWP, u_e) or relax the existing one (e.g., due to pile driving or …

Controlled Release Chemical Oxidation: Sodium Persulfate Encapsulated In Pvac Polymer, Mosarrat Samiha Kabir

Theses

In this study, sodium persulfate was encapsulated in polyvinyl acetate (PVAc) polymer to investigate the potential of activated persulfate to remediate total coliform and E. coli bacteria from contaminated water through a control release system. Controlled release structures were produced with the polymer and persulfate melted to form pellets at two different baking times. CRP structures containing 60 weight % sodium persulfates blended with 40 weight % polyvinyl acetate (PS- PVAc) were baked for 4 minutes and 10 minutes at 120ºC. The kinetics release of sodium persulfate was studied in a water system and in sand columns. Experimental results showed …

Effect Of Limited Tension Stiffening On Behavior Of Reinforced Concrete Panels In Shear., Xueying Wang, Jun Shang Kuang

Faculty of Science & Technology (THEi)

The principal tensile strength of cracked concrete is not well defined in existing models for predicting the shear response of reinforced concrete (RC) membrane elements; hence, the shear strength of RC elements is generally overestimated due to the unrealistic decreasing slope of tensile stress as the crack accumulates. In this paper, the effect of limited tension-stiffening behavior of cracked RC panels under pure shear stresses is investigated by proposing an analytical model named as the tension-stiffening fixed-angle truss model (TFTM). The proposed model includes the limited tension-stiffening effect of post-cracking reinforced concrete and adopts the fixed-angle theory. In the analysis …

Evaluating Shallow Mixing Protocols As Application Methods For Microbial Induced Calcite Precipitation Targeting Expansive Soil Treatment, Bhaskar C. S. Chittoori, Tasria Rahman, Malcolm Burbank, Arif Ali Baig Moghal

Civil Engineering Faculty Publications and Presentations

Expansive soils, also known as swell-shrink soils, undergo substantial volumetric changes due to moisture fluctuations from seasonal variations. These volumetric changes cause millions of dollars in damages annually. Microbial Induced Calcite Precipitation (MICP) is a promising soil improvement technique, which uses urease producing bacteria to precipitate calcium carbonate. In this study, a stabilization alternative for expansive soils was studied using MICP. Specifically, indigenous bacteria were stimulated by mixing enrichment and cementation solutions with expansive natural soils to precipitate calcium carbonate and make soil stronger and less expansive. This study examined three expansive soils with varying plasticity and mineralogical characteristics. Two …

Outside The Site Boundary, Timothy Kwan Fai Chan

Faculty of Science & Technology (THEi)

No abstract provided.

Effects Of Beam-Column Depth Ratio On Seismic Behaviour Of Non-Seismic Detailed Reinforced Concrete Beam-Column Joints, Ying Liu, Ho-Fai Wong, Sung-Hei Luk, Ching-Kit Tong, Hei Lam

Faculty of Science & Technology (THEi)

Four reinforced concrete exterior beam-column joints with open anchorage beam reinforcement, which are manufactured to simulate those in existing reinforced concrete framed buildings, are tested under reversed cyclic loads simulating earthquake excitation. The particular emphasis of this project is given to the effects of the beam-column depth ratio and the stirrup ratio in joints on the shear strength and seismic behaviour of the exterior joints without seismically designed details. The experimental results indicate that the stirrup placed in the beam-column joint cores can effectively improve the shear strength of the joint and enhance the seismic performance, and the shear strength …

The Scaling Limit Of The Membrane Model, Alessandra Cipriani, Biltu Dan, Rajat Subhra Hazra

Journal Articles

On the integer lattice, we consider the discrete membrane model, a random interface in which the field has Laplacian interaction. We prove that, under appropriate rescaling, the discrete membrane model converges to the continuum membrane model in d ≥ 2. Namely, it is shown that the scaling limit in d = 2, 3 is a Holder continuous random field, while in d ≥ 4 the membrane model converges to a random distribution. As a by-product of the proof in d = 2, 3, we obtain the scaling limit of the maximum. This work complements the analogous results of Caravenna and …

Ce 5500: Stochastic Hydrology, University Of Virginia, Julianne Quinn

All ECSTATIC Materials

This document is the syllabus for CE 5500: Stochastic Hydrology by instructor Julianne D. Quinn at the University of Virginia. The course is an elective class, open to upper-level undergraduate and graduate students.

Improving Traffic Safety At School Zones By Engineering And Operational Countermeasures, Md Hasibur Rahman

Electronic Theses and Dissertations

Safety issues at school zone areas have been one of the most important topics in the traffic safety field. Although many studies have evaluated the effectiveness of various traffic control devices (e.g., sign, flashing beacon, speed monitoring display), there is a lack of studies exploring different roadway countermeasures and the relationship between school-related factors and crashes. In this study, the most crash-prone school zone was identified in Orange and Seminole Counties, Florida, based on crash rate. Afterward, a microsimulation network was built in VISSIM environment to test different roadway countermeasures in the school zones. Three different countermeasures: two-step speed reduction …

Optimal Assessment Of Weigh-In-Motion Data For Structural Reliability Based Rating Of Bridge Superstructures, Sasan Siavashi

Wayne State University Dissertations

The first objectives of this research are to propose a simplified procedure to reduce the vehicle dataset need to be considered for load rating of bridge superstructures. The second objective is to explore the effectiveness of Reliability Based Design Optimization (RBDO) to develop a State-specific rating load model for a set of bridge superstructures. Finally, an alternative novel approach to develop rating models as effective as an ideal RBDO solution is proposed. The proposed solutions can substantially reduce the computational effort while not compromising the level of accuracy.

Effect Of Limited Tension Stiffening In Rc Elements Under Cyclic Loads., Xueying Wang, Jun Shang Kuang

Faculty of Science & Technology (THEi)

The tension capacity in cracked concrete is not well defined in existing shear models for reinforced concrete (RC) membrane elements under cyclic reversed loading, and the shear strength of RC elements is consequently overestimated due to the deviated decreasing branch of envelope of cyclic tensile stress-strain relationship. In this paper, the cyclic effect of limited tension stiffening of cracked RC elements is evaluated by proposing an analytical model named as the cyclic tension-stiffening fixed-angle truss model (CTFTM). The proposed model, based on fixed-angle theory, integrates unloading and reloading rules and accumulated damage into the limited tension-stiffening effect under cyclic loading …

Effects Of Eccentricity On Seismic Behavior Of Non-Seismically Designed Reinforced Concrete Beam-Column Joint, Ho-Fai Wong, Ying Liu, Sung-Hei Luk, Pok-Man Lee, Wing-Hei Kwong

Faculty of Science & Technology (THEi)

The staggering numbers of eccentric reinforced concrete beam-column joints without seismic design details were used in existing RC frame building due to geometrical constraints, which implied high susceptibility of the building structures to anticipated seismic risk. Three exterior RC beam-column joints were fabricated and tested, which were applied reversed cyclic loads to simulate seismic action. In this study, the effects of stirrup ratio in joints and the eccentricity which is defined as the distance between the axis of the beam and column on seismic performance are investigated. The test results provide a further understanding of the failure mode and shear …

Fragility Curves For Buildings In Hong Kong, Sung-Hei Luk, Ho-Fai Wong

Faculty of Science & Technology (THEi)

Fragility curves are the tools for evaluating the damage of structural or nonstructural components under different levels of ground excitation. It is also the necessary information for calculating the life-cycle cost of buildings during their design period. In this paper, development of fragility curves for buildings designed based on HK standard is presented. Two prototype models, which include three-storey and tenstorey reinforced concrete rigid frames, were considered. Incremental dynamic analysis was conducted under nine sets of past earthquake records with scaled peak ground accelerations. Maximum inter-storey drift ratio was selected as the damage indices and three performance levels were considered. …

Analysis Of Factors Influencing Return On Investment (Roi) For Building Information Modeling (Bim) Implementation, Tugce Kulaksiz

Wayne State University Dissertations

A research study was conducted to investigate and understand factors influencing Return on Investment of Building Information Modeling (BIM).

Research data was collected from 182 industry professionals (design firms, contractors and owners) using a survey instrument. The research data were evaluated by examining frequency distributions and running statistical analyses including an analysis of variance with post hoc tests and a multiple linear regression analysis. Furthermore, a simulation study was conducted to infer conclusions about the larger population from which the repeated samples were taken. The research findings revealed that the factors contributing to Return on Investment of BIM implementation were: …

The Resilient City: A Platform For Informed Decision-Making Process, Paul Niculescu-Mizil Gheorghe, Jarutpong Vasuthanasub, Adrian Gheorghe

Engineering Management & Systems Engineering Faculty Publications

As over half of the world’s inhabitants lives in metropolises, the rapid growth in urbanization has made cities becoming more and more exposed and vulnerable to a broad spectrum of threats and hazards. In order to respond to such difficulties, a concept of resilience is considered a significant component for the long-term planning and sustainable development of the cities. “Resilient City” is a new paradigm that challenges the idealistic principle of stability and resistance to change implicitly in sustainable development and success. However, building a resilient city requires a holistic approach, as well as the appropriate adoption of knowledge and …

Biomass Density Based Adjustment Of Lidar-Derived Digital Elevation Models: A Machine Learning Approach, Khalid Abdelwahab

Electronic Theses and Dissertations

Salt marshes are valued for providing protective and non-protective ecosystem services. Accurate digital elevation models (DEMs) in salt marshes are crucial for modeling storm surges and determining the initial DEM elevations for modelling marsh evolution. Due to high biomass density, lidar DEMs in coastal wetlands are seldom reliable. In an aim to reduce lidar-derived DEM error, several multilinear regression and random forest models were developed and tested to estimate biomass density in the salt marshes near Saint Marks Lighthouse in Crawfordville, Florida. Between summer of 2017 and spring of 2018, two field trips were conducted to acquire true elevation and …

Arterial-Level Real-Time Safety Evaluation In The Context Of Proactive Traffic Management, Jinghui Yuan

Electronic Theses and Dissertations

In the context of pro-active traffic management, real-time safety evaluation is one of the most important components. Previous studies on real-time safety analysis mainly focused on freeways, seldom on arterials. With the advancement of sensing technologies and smart city initiative, more and more real-time traffic data sources are available on arterials, which enables us to evaluate the real-time crash risk on arterials. However, there exist substantial differences between arterials and freeways in terms of traffic flow characteristics, data availability, and even crash mechanism. Therefore, this study aims to deeply evaluate the real-time crash risk on arterials from multiple aspects by …

Assessing Pedestrian Safety Conditions On Campus, Morgan Morris

Electronic Theses and Dissertations

Pedestrian-related crashes are a significant safety issue in the United States and cause considerable amounts of deaths and economic cost. Pedestrian safety is an issue that must be uniquely evaluated in a college campus, where pedestrian volumes are dense. The objective of this research is to identify issues at specific locations around UCF and suggest solutions for improvement. To address this problem, a survey that identifies pedestrian safety issues and locations is distributed to UCF students and staff, and an evaluation of drivers reactions to pedestrian to vehicle (P2V) warning systems is studied through the use of a NADS MiniSim …

Probabilistic Spatio-Magnitude Sinkhole Hazard Analysis For East Central Flrodia, Yong Je Kim

Electronic Theses and Dissertations

In Karst areas, sinkholes are a major geohazard that creates damage and economic loss to building and civil infrastructure. The main goal of the proposed study is to develop a probabilistic spatio-magnitude sinkhole susceptibility model that predicts the potential of sinkhole occurrence on a regional scale. The dissertation presents statistical techniques such as frequency ratio (FR) and logistic regression (LR), and a machine learning technique such as artificial neural network (ANN) to develop the sinkhole hazard models. The study area was limited to the East Central Floria (ECF) region. Seven hydrogeological factors were identified as key contributing factors to sinkhole …

Assessing The Safety And Operational Benefits Of Connected And Automated Vehicles: Application On Different Roadways, Weather, And Traffic Conditions, Md Sharikur Rahman

Electronic Theses and Dissertations

Connected and automated vehicle (CAV) technologies have recently drawn an increasing attention from governments, vehicle manufacturers, and researchers. Connected vehicle (CV) technologies provide real-time information about the surrounding traffic condition (i.e., position, speed, acceleration) and the traffic management center's decisions. The CV technologies improve the safety by increasing driver situational awareness and reducing crashes through vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I). Vehicle platooning with CV technologies is another key element of the future transportation systems which helps to simultaneously enhance traffic operations and safety. CV technologies can also further increase the efficiency and reliability of automated vehicles (AV) by collecting real-time …

Mechanical Study On Edge-Oxidized Graphene Oxide (Eogo) Reinforced Concrete, Mohammad Khawaji

Electronic Theses and Dissertations

It is known that graphene oxide (GO) has superior mechanical properties and can enhance mechanical properties of cement composites. However, Hummer produced conventional GOs have been limited to small-scale specimens (e.g., cement paste and mortar) and applications to concrete have not been implemented due to their high cost and large volume of concrete. Edge-oxidized graphene oxide (EOGO) is a low-cost, carbon-based nanomaterial produced by a mechanochemical process with ball milling and a non-toxic oxidizing agent. The low cost (less than $50/kg) of EOGO enables its use in bulk-scale concrete materials/structures, which is a prerequisite for the field implementation. In this …

Enhanced Concrete Bridge Assessment Using Artificial Intelligence And Mixed Reality, Enes Karaaslan

Electronic Theses and Dissertations

Conventional methods for visual assessment of civil infrastructures have certain limitations, such as subjectivity of the collected data, long inspection time, and high cost of labor. Although some new technologies (i.e. robotic techniques) that are currently in practice can collect objective, quantified data, the inspector's own expertise is still critical in many instances since these technologies are not designed to work interactively with human inspector. This study aims to create a smart, human-centered method that offers significant contributions to infrastructure inspection, maintenance, management practice, and safety for the bridge owners. By developing a smart Mixed Reality (MR) framework, which can …

Investigation Of Coastal Vegetation Dynamics And Persistence In Response To Hydrologic And Climatic Events Using Remote Sensing, Subrina Tahsin

Electronic Theses and Dissertations

Coastal Wetlands (CW) provide numerous imperative functions and provide an economic base for human societies. Therefore, it is imperative to track and quantify both short and long-term changes in these systems. In this dissertation, CW dynamics related to hydro-meteorological signals were investigated using a series of LANDSAT-derived normalized difference vegetation index (NDVI) data and hydro-meteorological time-series data in Apalachicola Bay, Florida, from 1984 to 2015. NDVI in forested wetlands exhibited more persistence compared to that for scrub and emergent wetlands. NDVI fluctuations generally lagged temperature by approximately three months, and water level by approximately two months. This analysis provided insight …

Influence Of Limit Equilibrium Methods In The Design Of Contiguous Cantilever Sheet Pile Walls Through Reliability-Based Analysis, Alvaro J. Mattos, Juan Camilo Viviescas, Juan Pablo Osorio

Conference papers

In geotechnical engineering the design of bored- pile walls is commonly performed in terms of the embedment length (D) defined according to the limit equilibrium methods (also known as balance methods) formulated by Krey, Blum, Rowe, Hansen and the empirical method of Look in sandy soils. The limit equilibrium methods are calculations associated with the shape of the earth pressures distributions in the shaft, earth pressures theories, geotechnical properties and safety factors, while the empirical criteria establish that the relationship between embedment and the free height (H) is of the order of D/H = 1.5. These design methods are complemented …

Image-Based Roadway Assessment Using Convolutional Neural Networks, Weilian Song

Theses and Dissertations--Computer Science

Road crashes are one of the main causes of death in the United States. To reduce the number of accidents, roadway assessment programs take a proactive approach, collecting data and identifying high-risk roads before crashes occur. However, the cost of data acquisition and manual annotation has restricted the effect of these programs. In this thesis, we propose methods to automate the task of roadway safety assessment using deep learning. Specifically, we trained convolutional neural networks on publicly available roadway images to predict safety-related metrics: the star rating score and free-flow speed. Inference speeds for our methods are mere milliseconds, enabling …