Modified Design Procedures For Bridge Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading,
2018
Portland State University
Modified Design Procedures For Bridge Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading, Arash Khosravifar, Jonathan Nasr
Civil and Environmental Engineering Faculty Publications and Presentations
Effective-stress nonlinear dynamic analyses (NDA) were performed for piles in the liquefiable sloped ground to assess how inertia and liquefaction-induced lateral spreading combine in long- and short-duration motions. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of durations and amplitudes. The NDA results showed that the pile demands increased due to (a) longer duration shakings, and (b) liquefaction-induced lateral spreading compared to nonliquefied conditions. The NDA results were used to evaluate the accuracy of the equivalent static analysis (ESA) recommended by Caltrans/ODOT for estimating pile demands. Finally, the NDA results were …
Laboratory Evaluation Of Internal And External Nutrient Removal To Control Algal Bloom In Eutrophic Lakes,
2018
South Dakota State University
Laboratory Evaluation Of Internal And External Nutrient Removal To Control Algal Bloom In Eutrophic Lakes, Sepideh Sadeghi
Electronic Theses and Dissertations
Eutrophication is one of the most widespread water quality problems in lakes and reservoirs. Frequent cyanobacterial blooms resulting from eutrophication can greatly damage aquatic ecosystems and pose a high risk to human health. Phosphorus (P) and nitrogen (N) are the major causes for eutrophic conditions and can enter to the aquatic ecosystem via different sources. The combination of phosphorus precipitation and sediment capping are promising technologies to minimize internal P loading and control harmful algal blooms in eutrophic lakes. Denitrification bioreactors have emerged as an important edge-of-field treatment technology to reduce nitrate-nitrogen loads from external sources. The objective of this …
Stresses In The End Zones Of Precast Inverted T-Beams With Tapered Webs,
2018
Wayne State University
Stresses In The End Zones Of Precast Inverted T-Beams With Tapered Webs, Ravi Siddharth Raja
Wayne State University Theses
Short to medium span composite bridges constructed with adjacent precast inverted T-beams and cast-in-place topping are intended to provide more resiliency against reflective cracking and time dependent effects compared to voided slabs and adjacent box girder systems. This thesis investigates the stresses in the end zones of such a uniquely shaped precast element. The transfer of prestressing force creates vertical and horizontal tensile stresses in the end zones of the girder. A series of 3-D finite element analyses were performed to investigate the magnitude of these tensile stresses. Hoyer effect is captured by modelling the strands as solid elements and …
Extraction Of Phase-Resolved Wave Data From X-Band Radar Imagery,
2018
Florida Institute of Technology
Extraction Of Phase-Resolved Wave Data From X-Band Radar Imagery, Alexandra Simpson
Link Foundation Ocean Engineering and Instrumentation Fellowship Reports
Typically, phase-resolved measurements of the sea surface are limited to single-point time series from in situ sensors, or arrays of multiple in situ sensors. The deployment of such devices is costly and time intensive, and the wave data they provide is limited in its spatial coverage and directional accuracy. Several remote sensing options, including optical video and X-Band marine radars, offer the possibility of full 2D reconstruction of the phase-resolved directional sea on spatial scales of kilometers. Ocean waves are visible in radar imagery as the ubiquitous backscatter from short wind ripples is modulated by the longer gravity waves. However, …
Evaluation Of Elastic Modulus Of Fiber-Reinforced Concrete,
2018
Florida Institute of Technology
Evaluation Of Elastic Modulus Of Fiber-Reinforced Concrete, Nakin Suksawang, Salam Wtaife, Ahmed Alsabbagh
Mechanical and Civil Engineering Faculty Publications
This paper determines the effect of discrete fibers on the elastic modulus of concrete and cement composites. Five types of discrete fibers consisting of steel, polypropylene, macro-polyolefin, polyvinyl alcohol (PVA), and basalt fibers were investigated. Results show that discrete fibers had little effect on elastic modulus for fiber-reinforced concrete (FRC) with coarse-to-fine aggregate ratio (C/S) greater than 1. However, for FRC with C/S smaller than 1 and fiber-reinforced cement composites (FRCCs), discrete fibers reduced the elastic modulus. Accordingly, a new elastic modulus equation is proposed to better estimate the elastic modulus of FRC with a maximum fiber volume fraction of …
Mechanical Bar Splices For Accelerated Construction Of Bridge Columns,
2018
South Dakota State University
Mechanical Bar Splices For Accelerated Construction Of Bridge Columns, Puskar Kumar Dahal
Electronic Theses and Dissertations
Mechanical bar splicing is an alternative method of connecting reinforcing bars in concrete structures compared to conventional lap splicing mainly to reduce bar congestion in joints. Recently, mechanical bar splices, which are also referred to as bar couplers, have been used to connect precast members to accelerate construction of concrete bridges and buildings. Current codes prohibit the use of couplers in the plastic hinge regions of bridge columns in high seismic zones. This may be because of a lack of systematic test data on the coupler performance, limited experimental studies on mechanically spliced bridge columns, and an engineering precaution. The …
Multi-Scale Investigation Of Microstructure, Fiber-Matrix Bond, And Mechanical Properties Of Ultra-High Performance Concrete,
2018
Missouri University of Science and Technology
Multi-Scale Investigation Of Microstructure, Fiber-Matrix Bond, And Mechanical Properties Of Ultra-High Performance Concrete, Zemei Wu
Doctoral Dissertations
"The main objective of this study is to provide new insights into enhancing fiber-matrix bond and mechanical properties of ultra-high performance concrete (UHPC). Three main strategies were investigated: 1) use of supplementary cementitious materials; 2) use of nano-particles; and 3) use of deformed fibers. A multi-scale investigation involving the evaluation of non-fibrous UHPC mortar phase (matrix), fiber-matrix interface phase, and then UHPC composite material was undertaken to determine microstructural characteristics, fiber bond to matrix, and key mechanical properties of the UHPC matrix and UHPC. Test results indicate that the incorporation of 10%-20% silica fume effectively improved the fiber-matrix bond and …
Sensitivity Of Rheological Properties Of Cement Paste With Scc Consistency,
2018
Missouri University of Science and Technology
Sensitivity Of Rheological Properties Of Cement Paste With Scc Consistency, Azadehalsadat A. Asghari
Doctoral Dissertations
"Robustness, which is defined as the capacity of a mixture to tolerate small variations in constituent elements, mixing parameters or temperature that are inevitable with production at any significant scale, is a key property to expand the practical implementation of self-consolidating concrete (SCC). At the first step, the effect of different amount of water, amount of superplastizer, mixing time, mixing speed and the addition time of superplastizer on the rheological properties of cement pastes with SCC consistency, has been evaluated. Two different SCC mix design concepts, the powder-type and VMA-type were selected for this research. The results show that the …
Compressive Behavior Of Masonry Columns Confined With Steel Reinforced Grout (Srg) Composite,
2018
Missouri University of Science and Technology
Compressive Behavior Of Masonry Columns Confined With Steel Reinforced Grout (Srg) Composite, Sarah Elizabeth Jemison
Masters Theses
"In this study, a new type of composite comprised of steel fiber cords embedded in a natural hydraulic lime mortar matrix, known as steel reinforced grout (SRG), is explored for the use in confinement of masonry columns. An experimental study was carried out to understand the behavior of solid clay brick masonry columns confined by SRG jackets. Twenty-four confined and seven unconfined columns with a square cross-section were tested to failure under a monotonic concentric compressive load. Test parameters considered were the column corner condition, number of fiber jacket layers, and number of fiber overlapping faces. SRG confinement improved the …
Numerical And Experimental Analysis Of Local Buckling Of Axially Loaded Steel Tubes Confined By Concrete And Frp,
2018
Missouri University of Science and Technology
Numerical And Experimental Analysis Of Local Buckling Of Axially Loaded Steel Tubes Confined By Concrete And Frp, Nicholas Colbert
Masters Theses
“The hollow core Fiber-Reinforced-Polymer (FRP) concrete circular-steel (HC-FCS) column consists of an outer circular fiber reinforced polymer (FRP) tube, an inner thin-walled circular steel tube concentrically aligned, and a concrete shell between them. Research has been performed on the performance of the member as a whole, but to date, there has been no investigation into the behavior of the steel tube confined in the column. 17 small-scale columns were tested under axisymmetric axial compressions applied directly to the steel tube under displacement control. The conducted parametric study examined the effects of diameter-to-thickness (D/t) ratio, concrete unconfined compressive strength, FRP thickness, …
Thermal Curing Efficiency Of Geopolymer Mortars,
2018
Missouri University of Science and Technology
Thermal Curing Efficiency Of Geopolymer Mortars, Simon Peter Sargon
Masters Theses
”Missouri is the fourth largest coal consumer in the U.S. with coal-fired power plants generate 81.3% of the electricity in the state which generate about 2.7 million tons of coal combustion residuals (CCRs) annually. The CCR, including fly ash, disposal issue is not limited to Missouri, rather it is a national issue with CCRs being the second largest waste stream in the U.S. Ninety million tons of fly ash are stored in landfills and ash ponds annually. Hence, using this waste product effectively is necessary. One of the emerging applications of fly ash is to use it as binder in …
Developing An Automated System For Supporting Strut Arrangement In Deep Excavation,
2018
Faculty of Engineering
Developing An Automated System For Supporting Strut Arrangement In Deep Excavation, Pisal Nov
Chulalongkorn University Theses and Dissertations (Chula ETD)
In strut arrangement, current software could detect the constructible problems like clashes. However, this software had some limitations including (1) unable to visualize all clash occurrences on each strut, (2) unable to distinguish between occurrence and non-occurrence of the clash, and (3) unable to check tolerance and spacing problems. Thus, the strut arrangement was still an inefficient process. The research objective was to develop an automated system for supporting strut arrangement in deep excavation. In the methodology, an in-depth interview was conducted to collect the information and knowledge of strut arrangement and analyzed with transcription analysis. This information and knowledge …
Assessing Corrosivity Of Galvanized Soil Reinforcements From Electrochemical Tests,
2018
University of Texas at El Paso
Assessing Corrosivity Of Galvanized Soil Reinforcements From Electrochemical Tests, Diana Alejandra Cabrera
Open Access Theses & Dissertations
The accurate estimation of the service lives of mechanically stabilized earth (MSE) walls requires a proper evaluation of the corrosion potential through electrochemical test methods. Robust field tests are required to assess the corrosivity of galvanized metal used in MSE walls. To simulate an environment similar to an MSE wall, cylindrical soil specimens about 12 in. (300 mm) in diameter and 10 in. (250 mm) in height were constructed. For every specimen, two instruments were used. The first instrument measured the polarization resistance corrosion tests carried out on galvanized strips and meshes, as well as epoxy-coated rebars. The second instrument …
High Recovery Inland Desalination: A Technical And Economic Performance Evaluation Of Zero Discharge Desalination And Other Technologies,
2018
University of Texas at El Paso
High Recovery Inland Desalination: A Technical And Economic Performance Evaluation Of Zero Discharge Desalination And Other Technologies, Malynda Aragon Cappelle
Open Access Theses & Dissertations
Increasing population and diminishing freshwater resources are leading to increased competition between users of freshwater, both in terms of surface water and groundwater. Desalination can augment the water supply, but conventional approaches like reverse osmosis are usually limited to 70-80% recovery. Inland brine disposal options are often limited, presenting significant technical and economic obstacles to implementing desalination technology. In comparison to conventional desalination technologies, high recovery desalination methods such as Zero Discharge Desalination (ZDD) offer substantially higher potable water yield (i.e., 95-98%) from brackish water. ZDD is a hybrid process that combines reverse osmosis (RO) or nanofiltration (NF) with electrodialysis …
Assessment Of Climate Change Impact On Hydraulic Design Procedures Of Bridges,
2018
University of Texas at El Paso
Assessment Of Climate Change Impact On Hydraulic Design Procedures Of Bridges, Anjuman Ara Akhter
Open Access Theses & Dissertations
The significant change in climate is evident from the records of increased temperature, changed precipitation pattern, increased frequency of extreme weather events like storms, floods, and so forth. Like other infrastructure highway infrastructures also suffer the consequences of these climate change. Since the hydraulic design of these infrastructures is performed using historical climate data, the designs may not be able to provide services because designs are not considering climate change influence especially in terms of precipitation intensity. This study aims at identifying the most accurate source of climate database that predicts future climate change with less uncertainty and links them …
Identifying The Safety Impact Of Signal Coordination Projects Along Urban Arterials Using A Meta-Analysis Method,
2018
Indiana State University
Identifying The Safety Impact Of Signal Coordination Projects Along Urban Arterials Using A Meta-Analysis Method, Michael R. Williamson, Ryan N. Fries, Yan Qi, Praveen Mandava
SIUE Faculty Research, Scholarship, and Creative Activity
The safety impact of changes to roadway operations have been of interests in recent years with the publication of the Highway Safety Manual. One area that is in need of further study is the safety impact of traffic signal coordination projects in urban areas. Specifically, this study seeks to identify the safety benefit from traffic signal coordination projects on major arterial roadways through urban areas using a before and after study with a comparison groups approach and a meta-analysis method. The findings suggest that traffic signal coordination could decrease total crashes by 21 percent, injury crashes by 52 percent and …
Investigation Of Ribbed Dome Including Tuned Mass Damper,
2018
Old Dominion University
Investigation Of Ribbed Dome Including Tuned Mass Damper, Ali Parva
Civil & Environmental Engineering Master's Projects
This research report presents the outcome of an investigation of lightweight ribbed steel dome structure. The proposed ribbed dome structure is studied both numerically and experimentally under static, natural vibration, and base excitation conditions. The base excitation is considered in the form of a sinusoidal as well as seismic loading in the form of a scaled-down 1940 El Centro earthquake. A numerical study of the ribbed dome is also conducted including a tuned mass damper (TMD). The performance of the dome is also compared with that of a hexagonal vertical structure showing a superior response of the dome under seismic …
Analyzing Destination Choices Of Tourists And Residents From Location Based Social Media Data,
2018
University of Central Florida
Analyzing Destination Choices Of Tourists And Residents From Location Based Social Media Data, Md Mehedi Hasnat
Electronic Theses and Dissertations
Ubiquitous uses of social media platforms in smartphones have created an opportunity to gather digital traces of individual activities at a large scale. Traditional travel surveys fall short in collecting longitudinal travel behavior data for a large number of people in a cost effective way, especially for the transient population such as tourists. This study presents an innovating methodological framework, using machine learning and econometric approaches, to gather and analyze location-based social media (LBSM) data to understand individual destination choices. First, using Twitter's search interface, we have collected Twitter posts of nearly 156,000 users for the state of Florida. We …
Preferential Pathways For Vapor Intrusion: Site Screening And Field Sampling Of Sewers To Assess Inhalation Exposure Risks,
2018
University of Kentucky
Preferential Pathways For Vapor Intrusion: Site Screening And Field Sampling Of Sewers To Assess Inhalation Exposure Risks, Evan James Willett
Theses and Dissertations--Civil Engineering
Hazardous waste sites and aging wastewater infrastructure are common in the United States. There are hundreds of thousands of contaminated sites and more than a million miles of sewer pipes. Populations living close to hazardous waste sites often suffer from increased risk of adverse health effects due to exposure to contaminated environmental media. Vapor intrusion is one process by which nearby populations can be exposed to volatile organic compounds (VOCs). Aging wastewater infrastructure is important for vapor intrusion site assessments because sewer pipes can serve as preferential vapor transport pathways. Near contaminated sites, pipe deterioration allows migration of contaminants into …
Advanced Technologies For Efficient Transportation Construction Inspection,
2018
University of Kentucky
Advanced Technologies For Efficient Transportation Construction Inspection, Clyde Wesley Newcomer Iv
Theses and Dissertations--Civil Engineering
Collecting load tickets is an example of an antiquated practice that puts inspectors in harm’s way either adjacent to traffic, in close proximity to moving or backing equipment, or at times requires climbing onto trucks to reach tickets. Technology exists to collect this information electronically allowing for safer, efficient inspection methods. Departments of Transportation are charged with inspecting an increasing work load with a diminishing number of inspection staff. Recently, doing more with less has led to the prioritization of inspection activities and resulted in less collection of data and visual inspection on projects. Technology advancements are available to improve …
