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Full-Text Articles in Civil Engineering

Analysis Of Spatial Discrepancies Between 76-Foot Close Range Photogrammetric And Terrestrial-Lidar Models, Abdoul K. Ouangre Jan 2022

Analysis Of Spatial Discrepancies Between 76-Foot Close Range Photogrammetric And Terrestrial-Lidar Models, Abdoul K. Ouangre

College of Graduate Studies: Theses & Dissertations

This study presents an analysis of the accuracy of a 3D model generated by two different methods. In the first method, the 3D model is generated via Laser Scanning. In the second method, the 3D model is generated via Close-range Photogrammetry from a drone flying at 76 feet above the ground. Photogrammetry is a photo-based technique that uses images to generate 3D models of objects where distances could be extracted from. Close-range photogrammetry is the approach of generating a 3D model from a camera placed anywhere between 1 foot and 1000 feet relative to the object. Terrestrial LiDAR is the …


Improving Active Learning Through Advanced Teaching Practices On An Online Course, Jin Ouk O. Choi Jan 2022

Improving Active Learning Through Advanced Teaching Practices On An Online Course, Jin Ouk O. Choi

UNLV Best Teaching Practices Expo

Since the outbreak of the COVID, there has been a great need to advance learning experiences and opportunities for students when the courses are taught remotely. To address the need, the author incorporated the teaching strategies learned from the Culturally Relevant & Responsive Teaching (CRRT) fellows program supported by the NSF TRANSCEnD project. In Fall 2021, the author implemented multiple new teaching techniques and strategies in the CEM453-653 course, delivered entirely online. The specific teaching practices and technologies are: 1) Delivering lectures both live (synchronous) and recordings (asynchronous); 2) Using adaptive technology (Mentimeter & WebEx Poll) with real-time feedback; 3) …


Experimental And Design Evaluation Of Multi-Bolted Gfrp Joints, Amir Hossein Houshmandyar Jan 2022

Experimental And Design Evaluation Of Multi-Bolted Gfrp Joints, Amir Hossein Houshmandyar

Graduate Theses, Dissertations, and Problem Reports (ETD)

For infrastructure system implementation, high strength/stiffness to self-weight ratio, corrosion resistance and ease of fabrication are just a few of the many advantages of pultruded fiber reinforced polymer (PFRP) composites over traditional construction materials. However, challenges of engineered FRP materials are addressed via continuous updating of design codes. For example, the anisotropic nature of FRP composite materials includes different mechanical properties in different directions (pull or longitudinal direction vs. transverse to pull direction) of a structural member, resulting in design complexities over isotropic materials. Typically, infrastructure systems are built by bolting FRP structural members because of certain advantages of bolted …


Finite Element Method Calculation Of A Prestressed Self Consolidating Concrete Beam, Vladyslav Machulsky Jan 2022

Finite Element Method Calculation Of A Prestressed Self Consolidating Concrete Beam, Vladyslav Machulsky

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, a prestressed concrete box beam produced for the Stalnaker Run Bridge (SRB) replacement project using self-consolidating concrete (SCC) was simulated using finite element method (FEM) numerical technique. ANSYS, a commercial FEM software, was used to build the prestressed SCC box beam model. The FEM model was developed to understand the behavior of concrete and steel under prestressing loads, long-term effects, and superimposed loads. The SOLID65 and REINF264 element types were chosen to simulate the behavior of concrete and steel materials. Experimentally measured mechanical properties of concrete from the SRB project were used in the analysis allowing for …


Stormwater Sensitivities To The Climatic And Land Cover Drivers In A Heavily Urbanized Coastal Basin Along The Northern Gulf Of Mexico, Usa., Md Faisal Razy Jan 2022

Stormwater Sensitivities To The Climatic And Land Cover Drivers In A Heavily Urbanized Coastal Basin Along The Northern Gulf Of Mexico, Usa., Md Faisal Razy

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stormwater runoff response in a complex coastal-urban basin varies with the changes in climatic and land cover drivers. This thesis aims to assess the runoff responses to variation in climatic and land cover variables and perform a sensitivity analysis in complex coastal-urban basins. The Buffalo San Jacinto Basin (BUSJ) of southeast Texas, USA was considered a pilot study area for this research. BUSJ is a heavily urbanized coastal basin, draining an area of 3132 km2 through the City of Houston, Texas into the northern Gulf of Mexico, USA. A process-based hydrological model was developed with fine spatio-temporal resolutions for …


Mechanical Response Of Vartm Infused Frp Composites, Andrew Kenney Jan 2022

Mechanical Response Of Vartm Infused Frp Composites, Andrew Kenney

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mechanical Response of VARTM based FRP composites

Andrew Kenney

The United States Department of Transportation (USDOT) recently created two new design specification for rail tank cars. These new types of classification, DOT-117 and DOT-117R, are designed with additional safety precautions to prevent hazardous chemicals from leaking out in case of a derailment. Features such as a thicker outer steel wall, head shield, and top and bottom valve protections provide additional protection compared to the current DOT-113 tank cars at the cost of additional weight. The WVU-CFC proposes a multifunctional, composite jacket that could be used in place of current tank …


Review Of Innovative Rehabilitation Techniques For Reinforced Concrete Buildings, Demetrius Karoubas Jan 2022

Review Of Innovative Rehabilitation Techniques For Reinforced Concrete Buildings, Demetrius Karoubas

Graduate Theses, Dissertations, and Problem Reports (ETD)

Building rehabilitation encompasses the act of repairing damaged structural elements, as well as the upgrading of older buildings to bring them up to modern standards. In recent years, due to the extreme economic and environmental cost of new construction, building rehabilitation is gaining ground as the most viable solution to the problem posed by damaged or substandard buildings. With the constant development of new materials with favorable properties and the improvement of our understanding of earthquakes, new rehabilitation techniques are being developed, improving on the efficiency and effectiveness of older ones. Reinforced Concrete (RC) buildings are a type of building …


Expanding The Applicability Of Press-Brake-Formed Tub Girders Through The Extension Of The Maximum Span Length And The Evaluation Of Pier Continuity, Robert M. Tennant Jan 2022

Expanding The Applicability Of Press-Brake-Formed Tub Girders Through The Extension Of The Maximum Span Length And The Evaluation Of Pier Continuity, Robert M. Tennant

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Short Span Steel Bridge Alliance (SSSBA) is a group of bridge and buried soil steel structure industry leaders who provide educational information on the design and construction of short-span steel bridges in installations up to 140 feet in length. Within the SSSBA technical working group, a modular, shallow press-brake-formed tub girder (PBFTG) was developed to address the demand in the short-span steel bridge market for rapid infrastructure replacement solutions. PBFTGs consist of modular, shallow, trapezoidal boxes fabricated from cold-bent structural steel plate. A concrete deck, or other deck option, may be placed on the girder, and the modular unit …


Salt Water Intrusion In Water Distribution Systems: Analysis, Solution, And Eco-Efficiency, Darud E Sheefa Jan 2022

Salt Water Intrusion In Water Distribution Systems: Analysis, Solution, And Eco-Efficiency, Darud E Sheefa

Dissertations, Master's Theses and Master's Reports

Since many water distribution systems (WDSs) experience saltwater intrusion, system behavior during saltwater intrusion is important. An alternative to the currently accepted WDS decontamination method of hydrant flushing is needed since during the current procedure all contaminated water is discharged to the surroundings which imposes environmental impacts. Hence, this research was conducted to study salt spread in different WDSs and to seek an alternative to hydrant flushing as a way of WDS decontamination. First, salt contamination was modelled in real water system models to document the salt spread. It was found that (1) if salt enters as a short pulse, …


Kinematics And Preliminary Fema P-695 Evaluation Of The Newz-Breakss Steel Boundary Frame With Buckling Restrained Brace Structural Fuses, Alexander M. Baker Jan 2022

Kinematics And Preliminary Fema P-695 Evaluation Of The Newz-Breakss Steel Boundary Frame With Buckling Restrained Brace Structural Fuses, Alexander M. Baker

Dissertations, Master's Theses and Master's Reports

Buckling Restrained Braced Frames (BRBFs) have become a popular seismic force resisting system (SFRS) due to their high ductility and energy dissipation. However, BRBFs are also susceptible to large residual drifts, which can make repair difficult. Efforts to reduce the residual drift of BRBFs typically involve special self-centering braces, or by using a dual system in tandem with the BRBF. This study proposes an alternative approach, in which a self-centering steel rocking frame is used as the boundary frame for the BRBF. The proposed system, called the NewZ-BREAKSS Buckling Restrained Braced Frame (NZ-BRBF) utilizes the recently proposed NewZ-BREAKSS (NZ) boundary …


Cive 440: Reinforced Concrete Design I: Faculty-Led Inquiry Into Reflective And Scholarly Teaching (First) Course Portfolio, Chungwook Sim Jan 2022

Cive 440: Reinforced Concrete Design I: Faculty-Led Inquiry Into Reflective And Scholarly Teaching (First) Course Portfolio, Chungwook Sim

UNL Faculty Course Portfolios

This Faculty-led Inquiry into Reflective and Scholarly Teaching (FIRST) Course Portfolio documents the instructor’s teaching practices and student learning for Reinforced Concrete Design I (CIVE 440) course. The contents of this course portfolio captures the CIVE 440 course that was taught on the Lincoln campus during the semester of Fall 2022. CIVE 440 is a structural engineering design elective offered every year in the Department of Civil and Environmental Engineering on both Lincoln and Omaha campus at University of Nebraska-Lincoln (UNL). The course objective is to help students to be able to use theory and experience to proportion and detail …


Climatic And Land Cover Sensitivities Of Stormwater Runoff In A Coastal Natural-Urban Basin Of Texas, Usa., Nusrat Nasrin Khan Jan 2022

Climatic And Land Cover Sensitivities Of Stormwater Runoff In A Coastal Natural-Urban Basin Of Texas, Usa., Nusrat Nasrin Khan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Changes in climatic and land use drivers typically drive stormwater runoff quantity and quality. This study focuses on determining the stormwater runoff sensitivities to variation in climatic and land cover changes in a coastal natural-urban basin. A mechanistic hydrologic model was developed for the Spring San Jacinto Basin (SSJB) of Texas, USA considering the basin as a pilot study area by using the U.S. Environmental Protection Agency (EPA)’s Storm Water Management Model 5.2. The SSJB drains an area of 1949 km2 ultimately into the northern Gulf of Mexico, USA through peripheral neighborhoods of the Greater Houston area. The model …


Stormwater Runoff Response Under Changing Climate And Land Uses Across Gradients Of Inland And Coastal Urban-Natural Basin, Mahmood Khan Jan 2022

Stormwater Runoff Response Under Changing Climate And Land Uses Across Gradients Of Inland And Coastal Urban-Natural Basin, Mahmood Khan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Climatic variability has caused significant shifts in the magnitude, frequency and spatiotemporal distribution of precipitation, generating excessive runoff that leads to frequent occurrences of extreme hydrologic events such as the pluvial (rainfall accumulation) and fluvial (riverine) floods. The conversion of natural areas into urban lands is further exacerbating the rainfall accumulation by increasing surface imperviousness that hinders infiltration of water into the soil. This dissertation predicts and characterizes potential shifts in the future annual stormwater runoff
volumes and runoff extremes under the standalone and coupled changes in climate and land use across inland and coastal urban-natural settings. The research was …


Characterization And Utilization Of Alkali-Activated Concrete For Sustainable Infrastructures, Eslam Gomaa Jan 2022

Characterization And Utilization Of Alkali-Activated Concrete For Sustainable Infrastructures, Eslam Gomaa

Doctoral Dissertations

“This study has investigated the feasibility of using locally available fly ashes (FAs) to synthesize alkali-activated concrete (AAC) for different structural and repair applications. Using AAC made of 100% FA reduces global CO2 emissions, saves energy, and decreases raw material consumption during the production process of ordinary Portland cement. Class C FAs, sourced from Labadie, Jeffery City, Kansas City, Thomas Hill, and Sikeston power plants in the state of Missouri, were used to synthesize the AAC. Sodium silicate (SS), Na2SiO3, and sodium hydroxide (SH), NaOH were used as the alkali activators. Slag, crumb rubber, and air-entraining admixture were used as …


Strategies To Improve Shrinkage Resistance Of Cement-Based Materials For Extrusion-Based 3d Printing, Kavya Vallurupalli Jan 2022

Strategies To Improve Shrinkage Resistance Of Cement-Based Materials For Extrusion-Based 3d Printing, Kavya Vallurupalli

Doctoral Dissertations

"The main objective of this study is to develop new generation of shrinkage-resistant 3D printable mortar mixtures. To this end, the research work was carried out to: i) identify key material and processing parameters that affect printability; ii) investigate the influence of water-to-cement ratio, superplasticizer dosage, and welan gum content on mortar printability; iii) propose a “printability window” where rheological properties and desorptivity can secure successful printing; iv) investigate effect of shrinkage mitigation materials (expansive agent (EA), pre-saturated lightweight sand (LWS), superabsorbent polymers (SAP), and shrinkage reducing admixture) on printability and shrinkage performance of mortar; and v) evaluate the effect …


Design And Performance Of Self-Consolidating And Thixotropic Ultra-High-Performance Concrete For Infrastructure Construction And Rehabilitation, Le Teng Jan 2022

Design And Performance Of Self-Consolidating And Thixotropic Ultra-High-Performance Concrete For Infrastructure Construction And Rehabilitation, Le Teng

Doctoral Dissertations

"The objective of this research is to develop two classes of ultra-high-performance concrete (UHPC), one with self-consolidating consistency and the other with improved thixotropy. Tailoring the rheological properties of low yield stress UHPC can improve dispersion and orientation of steel fibers used in the design of UHPC, hence enhancing the tensile and flexural properties. Similarly, improving the thixotropy of UHPC can enable unique performance for the design of thin bonded bridge deck overlay. The research investigated various thixotropy enhancing admixtures to enhance the structural build-up at rest of UHPC. A total of 16 bonded overlay slab specimens were used to …


Use Of Cellular Concrete For Air Convection Embankment To Protect Permafrost Foundation In Cold Regions, Hanli Wu Jan 2022

Use Of Cellular Concrete For Air Convection Embankment To Protect Permafrost Foundation In Cold Regions, Hanli Wu

Doctoral Dissertations

"Crushed-rock air convection embankment (ACE) has been used to mitigate thaw settlement, and pavement distresses caused by climatic extremes in permafrost regions for over three decades. However, the desired crushed rocks needed for ACE are not readily available in many areas of interior Alaska. Burdened by the need to ship suitable rocks to remote locations, the cost of constructing an ACE is often prohibitively high, which prevents its wide use in Alaska. An existing cementitious material, cellular concrete, may provide the solution.

This study intends to systematically characterize the heat transfer patterns of ACE and identify the performance benefits of …


Investigating The Interaction Between The Recycled Components And The Asphalt Binders, Plant, Lab, And Field Mixes, Eslam Deef-Allah Jan 2022

Investigating The Interaction Between The Recycled Components And The Asphalt Binders, Plant, Lab, And Field Mixes, Eslam Deef-Allah

Doctoral Dissertations

"Modifying asphalt binders and mixes with recycled components is common practice due to their environmental and economic merits. Literature has indicated that different recycled components interact with (blend with) asphalt differently, ranging from no blending, partial blending, or full blending. The degree of blending between recycled components and virgin asphalt binders (VABs) and the exchanged components impact the performance of modified asphalt binders. However, the nature of the interaction process between the recycled components and the VABs is not fully understood. The primary objective of this study was to explore the interactions between recycled components and VABs. By understanding the …


Theoretical Determination Of The Yield Curve For Unsaturated Soils, Sara Fayek Jan 2022

Theoretical Determination Of The Yield Curve For Unsaturated Soils, Sara Fayek

Doctoral Dissertations

"An important step to developing a good understanding of the behavior of unsaturated soils is to adopt a formal and simple constitutive framework and to conduct high-quality and short-time experiments. Barcelona Basic Model (BBM) was the first elastoplastic constitutive model for unsaturated soils. The yield curve, which separates the elastic region from the elastoplastic region, is an important aspect of constitutive modeling for unsaturated soils. Most concepts for unsaturated soils were developed based upon the results from suction-controlled triaxial (SCTX) tests. Though, the SCTX tests on unsaturated soils are costly, time-consuming, and laborious, and their results are questionable. This study …


Synergistic Effect Of Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Cementitious Composites, Kamran Aghaee Jan 2022

Synergistic Effect Of Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Cementitious Composites, Kamran Aghaee

Doctoral Dissertations

"The advantages of using shrinkage mitigating strategies to reduce shrinkage and mitigate cracking of concrete is well documented. However, the benefits and drawbacks of employing multiple strategies have not been explored. The main objective of this study is to provide insights into the mechanisms of using multiple strategies to enhance shrinkage and cracking resistance to promote the properties of high-performance cementitious composites (HPC) designated for infrastructural construction, repair, and 3D printing applications. HPC mixtures were prepared with steel and synthetic macro and microfibers, expansive agent (EA), and shrinkage reducing admixture (SRA) coupled with various curing methods e.g., internal curing using …


Promoting Distributed Energy Deployment And Diffusion For Sustainable Civil Infrastructure Using Multi-Agent Based Modeling And Quantitative Analytics, Gasser Ali Jan 2022

Promoting Distributed Energy Deployment And Diffusion For Sustainable Civil Infrastructure Using Multi-Agent Based Modeling And Quantitative Analytics, Gasser Ali

Doctoral Dissertations

"Distributed Solar Generation (DSG) using small-scale Photo-Voltaic (PV) is an evolving technology with increasingly growing market penetration due to its significant benefits to consumers and broader power systems. DSG is sustainable, provides reliability, and is cost-effective where solar energy is abundant. However, the increasingly growing adoption of DSG creates uncertainties in forecasting electric power demand and market behavior. It also causes concerns of a “utility death spiral”. To this end, the goal of this research is to critically analyze the diffusion and benefits of DSG in the electric power infrastructure as a complex System-of-Systems (SoS). Specifically, this dissertation addresses the …


Deep Learning-Based Surrogate Models For Post-Earthquake Damage Assessment, Xinzhe Yuan Jan 2022

Deep Learning-Based Surrogate Models For Post-Earthquake Damage Assessment, Xinzhe Yuan

Doctoral Dissertations

"Seismic damage assessment is a critical step to enhance community resilience in the wake of an earthquake. This study aims to develop deep learning-based surrogate models for widely used fragility curves to achieve more accurate and rapid assessment in practice. These surrogate models are based on artificial neural networks trained from the labelled ground motions whose resulting damage classes on targeted structures are determined by nonlinear time history analyses. The development of various surrogate models is progressed in four phases. In Phase I, the multilayer perceptron (MLP) is used to develop multivariate seismic classifiers with up to 50 hand-crafted intensity …


Investigating Changes In Trends Of Traffic Crashes Due To Covid-19 Pandemic In Florida’S Freeways, Ntagwanko Kisabanzira Jan 2022

Investigating Changes In Trends Of Traffic Crashes Due To Covid-19 Pandemic In Florida’S Freeways, Ntagwanko Kisabanzira

UNF Graduate Theses and Dissertations

The COVID-19 pandemic outbreak caused a shift in traffic patterns that have in turn influenced a change in traffic accident trends. Due to stay-at-home orders that were issued across the United States, transportation agencies reported low traffic demands on highways after the pandemic outbreak. Low traffic volumes are associated with relatively higher speeds that are linked to increased severity of crashes. Several states reported an increase in fatal crashes after the outbreak of the COVID-19 pandemic. This paper evaluates the traffic crash trends on three interstates in Florida (I-10, I-75, and I-95) and sheds light on what happened before, during, …


Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney Jan 2022

Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney

UNF Graduate Theses and Dissertations

Ottawa 50/70 sand specimens and natural beach sand samples were treated using bio-augmented geomicrobies via a surface percolation technique. Testing was conducted on these specimens to determine how resultant calcium carbonate precipitation changed as a function of temperature, depth from the surface, and in the presence of magnesium. Specifically, x-ray Diffraction (XRD), a Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were used to determine and quantify the presence of calcium carbonate and its associated phase. Results showed a direct relationship between temperature and precipitated calcium carbonate. In addition, as an unintended consequence associated with the treatment, ammonium …


Comparison Between Pervious Oyster Shell Habitat (Posh) Unit And Reef Ball Performance Along An Eroding Shoreline In Northeast Florida, Jacob Waggoner Jan 2022

Comparison Between Pervious Oyster Shell Habitat (Posh) Unit And Reef Ball Performance Along An Eroding Shoreline In Northeast Florida, Jacob Waggoner

UNF Graduate Theses and Dissertations

This study compared two methods of shoreline protection – the common Reef Ball and the novel Pervious Oyster Shell Habitat (POSH). Both structures are meant to attenuate wave energy and subsequently reduce shoreline erosion. While Reef Balls have a long, documented history of effectively mitigating beach erosion, POSH units are new structures and their effectiveness had not yet been previously assessed. Clusters of POSH units and Reef Balls were deployed at the Timucuan Ecological and Historic Preserve’s shoreline at Kingsley Plantation. Wave staffs were placed seaward and shoreward from these clusters and wave heights were measured over a holiday weekend …


Methodology To Treat Bottom Friction Losses For Modeling Wave Transformation From Deepwater To The Nearshore: An Application In Northeast Florida, Oscar Solisromero Jan 2022

Methodology To Treat Bottom Friction Losses For Modeling Wave Transformation From Deepwater To The Nearshore: An Application In Northeast Florida, Oscar Solisromero

UNF Graduate Theses and Dissertations

Designers and other practitioners confront a wide range of problems in the coastal zone, which often require long-term nearshore wave data. However, such data are usually quite scarce. Consequently, either wave measurements from buoys deployed in deep water, or archived deepwater wave hindcast information, must be utilized by rigorous, physics-based transformation to the site of interest using one of many available numerical models. A main issue in conducting such an effort is accounting for losses in wave energy due to bottom friction, for which establishing a suitable bed friction coefficient (Cf) can be problematic. In the present study, …


On A New Framework For Detecting, Classifying, And Forecasting Floods For Large-Scale Flood Risk Analysis, Equisha Glenn Jan 2022

On A New Framework For Detecting, Classifying, And Forecasting Floods For Large-Scale Flood Risk Analysis, Equisha Glenn

Dissertations and Theses

Increasing trends in flooding events are projected to continue as climate changes have increased the chance of extreme weather events. Given the significant, damaging impacts of extreme floods, the ability to effectively model floods is crucial for risk management and mitigation of the impacts of these extreme flooding events. This dissertation presents a new framework for detecting and predicting large-scale flood risk in the United States using climate information. This methodology categorizes regional, simultaneous floods into an index that is used to forecast the risk of extreme flooding a season ahead. The index proposed herein, named the Spatial Flood Index …


A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir Jan 2022

A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir

Dissertations and Theses

Street flooding is problematic in urban areas, where impervious surfaces, such as concrete, brick, and asphalt prevail, impeding the infiltration of water into the ground. During rain events, water ponds and rise to levels that cause considerable economic damage and physical harm. The main goal of this dissertation is to develop novel approaches toward the comprehension of urban flood risk using data science techniques on crowd-sourced data. This is accomplished by developing a series of data-driven models to identify flood factors of significance and localized areas of flood vulnerability in New York City (NYC). First, the infrastructural (catch basin clogs, …


การประเมินความเหมาะสมทางวิศวกรรมของการนำแอนไอโอนิคแอสฟัลต์อิมัลชันและน้ำยางพาราเป็นส่วนผสมในแอสฟัลต์คอนกรีตแบบผสมเย็น, ไม้ไท เกษสุวรรณ์ Jan 2022

การประเมินความเหมาะสมทางวิศวกรรมของการนำแอนไอโอนิคแอสฟัลต์อิมัลชันและน้ำยางพาราเป็นส่วนผสมในแอสฟัลต์คอนกรีตแบบผสมเย็น, ไม้ไท เกษสุวรรณ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในการก่อสร้างถนนแอสฟัลต์อิมัลชันสามารถแบ่งได้เป็น 2 ชนิดได้แก่ ชนิดประจุไฟฟ้าเป็นบวก (Cationic Asphalt Emulsion) และ ชนิดประจุไฟฟ้าเป็นลบ (Anionic Asphalt Emulsion) โดยประจุไฟฟ้าของแอสฟัลต์อิมัลชันสามารถส่งผลต่อการยึดเกาะระหว่างมวลรวมชนิดต่างๆ เนื่องด้วยมวลรวมแต่ละชนิดก็มีประจุไฟฟ้าที่แตกต่างกันไป ในการออกแบบถนนนั้นความชื้นก็เป็นส่วนสำคัญที่ต้องคำนึงเนื่องจากความชื้นจะทำให้ถนนมีความแข็งแรงที่ลดลง ซึ่งเป็นผลกระทบหลักที่จะก่อให้เกิดความเสียหายขึ้น เนื่องจากความชื้นจะทำลายการยึดเกาะระหว่างผิวของวัสดุมวลรวมกับแอสพัลต์ ทำให้เกิดการหลุดลอกของวัสดุมวลรวมจากผิวทางแอสฟัลต์คอนกรีต และเพื่อหลีกเลี่ยงการหลุดลอกของผิวถนนซึ่งอาจก่อให้เกิดผิวทางชำรุดก่อนเวลาอันควร งานวิจัยนี้จึงมุ่งเน้นที่จะศึกษาและประเมินคุณสมบัติด้านความต้านทานการหลุดลอก และ คุณสมบัติด้านความต้านทานความเสียหายเนื่องจากความชื้น โดยใช้การทดสอบ Rolling Bottle Test และ Indirect Tensile strength test ซึ่งจะนำแอสฟัลต์อิมัลชันทั้งชนิดประจุบวกและประจุลบ รวมไปถึงการใช้น้ำยางธรรมชาติเป็นส่วนผสม และใช้มวลรวมทั้ง 3 ชนิด ได้แก่ หินปูนชลบุรี หินปูนสระบุรี และ หินบะซอลต์บุรีรัมย์ โดยในการทดสอบพบว่า แอสฟัลต์อิมัลชันต่างชนิดกันมีผลต่อความต้านทานการหลุดลอกของมวลรวมแต่ละชนิดแตกต่างกันอย่างมีนัยสำคัญ และการเติมน้ำยางธรรมชาติที่ 10% นั้นสามารถเพิ่มค่าความต้านทานการหลุดลอกของหินปูนทั้ง 2 ชนิดได้แต่จะมีค่าลดลงในการเติม 20% และสำหรับในหินบะซอลต์นั้นมีค่าลดลงทั้ง 10% และ 20% ของการเติมน้ำยางพารา และ จากผลการทดสอบ ITS พบว่าสำหรับหินทั้งสามชนิด เมื่อนำไปใช้งานกับแอสฟัลต์อิมัลชันชนิดแอนไอออนิกมีค่าความต้านทานความเสียหายเนื่องจากความชื้นสูงกว่าแอสฟัลต์อิมัลชันชนิดแคทไอออนิก และสำหรับการเติมน้ำยางพาราที่ 10% ทำให้ค่าความต้านทานความเสียหายเนื่องจากความชื้นลดลงเมื่อเทียบกับการที่ไม่เติม


การพัฒนาแบบจำลองทางเลือกรูปแบบการเดินทางจากการสำรวจข้อมูลการเดินทางทางอ้อมจากข้อมูลโทรศัพท์เคลื่อนที่, จอมพล เพชราวุธ Jan 2022

การพัฒนาแบบจำลองทางเลือกรูปแบบการเดินทางจากการสำรวจข้อมูลการเดินทางทางอ้อมจากข้อมูลโทรศัพท์เคลื่อนที่, จอมพล เพชราวุธ

Chulalongkorn University Theses and Dissertations (Chula ETD)

การสำรวจข้อมูลการเดินทางในครัวเรือนด้วยแบบสอบถามเป็นวิธีการสำรวจข้อมูลปริมาณการเดินทางและพฤติกรรมการเดินทางที่ได้รับความนิยมอย่างแพร่หลายตั้งแต่ในอดีตจนถึงปัจจุบัน เนื่องจากข้อมูลที่ได้จากการสำรวจมีความละเอียดสูงและสามารถนำข้อมูลไปวิเคราะห์พฤติกรรมการเดินทางได้อย่างเหมาะสม อย่างไรก็ตาม วิธีดังกล่าวต้องใช้ต้นทุนทั้งด้านค่าใช้จ่ายและระยะเวลาในการสำรวจข้อมูลอย่างมาก ด้วยเหตุนี้ งานวิจัยนี้จึงมีวัตถุประสงค์เพื่อศึกษาความเป็นไปได้ในการนำฐานข้อมูลทุติยภูมิขนาดใหญ่มาใช้เพื่อวิเคราะห์พฤติกรรมการเดินทาง โดยมุ่งเน้นไปที่การอธิบายพฤติกรรมการเลือกรูปแบบการเดินทาง ด้วยการสร้างแบบจำลองเนสเต็ดโลจิตจากข้อมูลสัญญาณโทรศัพท์เคลื่อนที่ของโครงการศึกษาการพัฒนานวัตกรรมระบบวิเคราะห์ฐานข้อมูลขนาดใหญ่เพื่อการขนส่งสินค้าด้วยรถบรรทุกและการเดินทางของคนในเขตกรุงเทพมหานครและปริมณฑล ระยะที่ 1 กรุงเทพมหานคร ของสำนักงานนโยบายและแผนการขนส่งและจราจร ซึ่งผ่านกระบวนการจำแนกรูปแบบและวัตถุประสงค์ของการเดินทางมาแล้ว และสามารถใช้ทดแทนการสำรวจพฤติกรรมการเดินทางโดยตรงได้ โดยแบบจำลองที่พัฒนาขึ้นด้วยวิธีการประเมินความพึงพอใจแบบเปิดเผยสามารถอธิบายปัจจัยที่มีผลต่อพฤติกรรมการเลือกรูปแบบการเดินทางของผู้ใช้โทรศัพท์เคลื่อนที่ในพื้นที่กรุงเทพมหานครและปริมณฑลตามวันและช่วงเวลาในการเดินทาง เช่น ระยะทาง ระยะเวลา ค่าใช้จ่าย วัตถุประสงค์ของการเดินทาง เป็นต้น และผลการศึกษาสามารถแสดงตารางจุดต้นทางและปลายทางในการเดินทางซึ่งแบ่งเป็น 209 พื้นที่ย่อย (ระดับแขวงในพื้นที่กรุงเทพมหานครและระดับอำเภอใน 5 จังหวัดปริมณฑล) ตามรูปแบบการเดินทาง (รถยนต์ส่วนบุคคล รถโดยสารประจำทาง รถไฟฟ้าขนส่งมวลชน รถไฟชานเมือง เรือโดยสาร) ได้ตามวันและช่วงเวลาในการเดินทาง