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2020

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Articles 1591 - 1620 of 1829

Full-Text Articles in Civil and Environmental Engineering

A Framework For Sustainable Procurement Practice In The Irish Construction Industry, Duga Jamus Ewuga Jan 2020

A Framework For Sustainable Procurement Practice In The Irish Construction Industry, Duga Jamus Ewuga

Doctoral

The Architectural, Engineering and Construction (AEC) sector has been called upon to develop innovative strategies to drive sustainability. Despite the efforts and commitments made, their performance is still observed to be low, this has been linked to the low level of understanding of practitioners. Also noted was the lack of interest by firms due to the uncertainty of the benefits of committing to long term investments. Nevertheless, academic literature and reports have stated that firms nowadays utilise their procurement mechanism to drive their sustainability practice. However, there is a gap in understanding how construction firms adopt and embed sustainability in …


Peak Pressures On Low Rise Buildings: Cfd With Les Versus Full Scale And Wind Tunnel Measurements, Aly Mousaad Aly, Hamzeh Gol-Zaroudi Jan 2020

Peak Pressures On Low Rise Buildings: Cfd With Les Versus Full Scale And Wind Tunnel Measurements, Aly Mousaad Aly, Hamzeh Gol-Zaroudi

Faculty Publications

This paper focuses on the processes of wind flow in the atmospheric boundary layer, to produce realistic full-scale pressures for the design of low-rise buildings. CFD with LES turbulence closure is implemented on a scale 1:1 prototype building. A proximity study was executed computationally in CFD with LES that suggests new recommendations on the computational domain size, in front of a building model, apart from common RANS-based guidelines (e.g. COST and AIJ). Our findings suggest a location of the test building, different from existing guidelines, and the inflow boundary proximity influences pressure correlation and reproduction of peak loads. The CFD …


Feasibility Study Of Development Of Ultra-High Performance Concrete (Uhpc) For Highway Bridge Applications In Nebraska, Flavia Ribeiro Furtado De Mendonca, Mostafa Abo El-Khier, George Morcous, Jiong Hu Jan 2020

Feasibility Study Of Development Of Ultra-High Performance Concrete (Uhpc) For Highway Bridge Applications In Nebraska, Flavia Ribeiro Furtado De Mendonca, Mostafa Abo El-Khier, George Morcous, Jiong Hu

Nebraska Department of Transportation: Research Reports

Ultra-high performance concrete (UHPC) is a new class of concrete that has superior mechanical, durability, and workability properties that far exceed those of conventional concrete. To achieve these properties, a specific mix design with a very dense internal structure, fiber reinforcement, and low water-to-binder ratio (w/b) is commonly used. The goal of this research is to develop a non-proprietary UHPC mix with constituent materials that are readily available in the state of Nebraska for bridge construction applications. In developing this mix, the particle packing model is used, and an experimental study of the impact of various design parameters on the …


Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen Jan 2020

Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen

Nebraska Department of Transportation: Research Reports

Tie bars are epoxy coated steel bars that connect the longitudinal joints in concrete pavement. Tie bars prevent faulting and joint separation between lanes Tie bars can be placed into the plastic concrete or inserted after curing by drilling and anchoring with epoxy or non-shrink grout. The specification for the tie bars requires the use of a No. 5 bar, 18 inches long and shall meet ASTM A775 / A775M [1], Section 1020.The Nebraska Department of Transportation “Standard Specifications for Highway Construction,” (Section 603.03) requires contractors to mechanically insert tie bars into the face of pavements during construction. Tie bars …


Influence Of Curing Conditions On Concrete Specimens (Cylinders) In Hot And Cold Weather In The Field, Wally Heyen, Lieska Halsey, Tim Krason, David Hansen Jan 2020

Influence Of Curing Conditions On Concrete Specimens (Cylinders) In Hot And Cold Weather In The Field, Wally Heyen, Lieska Halsey, Tim Krason, David Hansen

Nebraska Department of Transportation: Research Reports

No abstract provided.


Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic Jan 2020

Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic

Theses and Dissertations--Computer Science

Understanding free-flow speed is fundamental to transportation engineering in order to improve traffic flow, control, and planning. The free-flow speed of a road segment is the average speed of automobiles unaffected by traffic congestion or delay. Collecting speed data across a state is both expensive and time consuming. Some approaches have been presented to estimate speed using geometric road features for certain types of roads in limited environments. However, estimating speed at state scale for varying landscapes, environments, and road qualities has been relegated to manual engineering and expensive sensor networks. This thesis proposes an automated approach for estimating free-flow …


Historical Trends In Air Temperature, Precipitation, And Runoff Of A Plateau Inland River Watershed In North China, Along Zhang, Ruizhong Gao, Xixi Wang, Tingxi Liu, Lijing Fang Jan 2020

Historical Trends In Air Temperature, Precipitation, And Runoff Of A Plateau Inland River Watershed In North China, Along Zhang, Ruizhong Gao, Xixi Wang, Tingxi Liu, Lijing Fang

Civil & Environmental Engineering Faculty Publications

Understanding historical trends in temperature, precipitation, and runoff is important but incomplete for developing adaptive measures to climate change to sustain fragile ecosystems in cold and arid regions, including the Balagaer River watershed on the Mongolian Plateau of northeast China. The objective of this study was to detect such trends in this watershed from 1959 to 2017. The detection was accomplished using a Mann-Kendall sudden change approach at annual and seasonal time scales. The results indicated that the abrupt changes in temperature preceded that in either runoff or precipitation; these abrupt changes occurred between 1970 and 2004. Significant (α = …


Measurement Of Sub-2 Nm Stable Clusters During Silane Pyrolysis In A Furnace Aerosol Reactor, Miguel Vazquez-Pufleau, Yang Wang, Pratim Biswas, Elijah Thimsen Jan 2020

Measurement Of Sub-2 Nm Stable Clusters During Silane Pyrolysis In A Furnace Aerosol Reactor, Miguel Vazquez-Pufleau, Yang Wang, Pratim Biswas, Elijah Thimsen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The initial stages of particle formation are important in several industrial and environmental systems; however, the phenomenon is not completely understood due to the inability to measure cluster size distributions. A high resolution differential mobility analyzer with an electrometer was used to map out the early stages of Si particle formation from pyrolysis of SiH4 in a furnace aerosol reactor. We detected for the first time subnanometer stable clusters from silane pyrolysis, and the diameter was measured to be about 0.7 nm. This diameter is within the range of probable sizes that the reported families of critical silane clusters could …


Computational Fluid Dynamics Study Of The Effects Of Secondary Flows In 90-Degree Pipe Elbow Erosion, O. Ayala, G. Rivera-Hernández, C. Knight Jan 2020

Computational Fluid Dynamics Study Of The Effects Of Secondary Flows In 90-Degree Pipe Elbow Erosion, O. Ayala, G. Rivera-Hernández, C. Knight

Engineering Technology Faculty Publications

Computational fluid dynamics (CFD) of particle-laden fluid flows through a 90-degree pipe elbow at Reynolds numbers 1,000 and 10,000 were completed; for different dimensionless elbow curvature ratios of 1.0, 1.5, and 2.5; and for particles with different Stokes numbers of 0.01, 0.1, 0.5, 1.0, 5.0, and 10.0. There were two scenarios in the study. For the first, the particles felt drag from the primary (or the axial) flow as well as from the secondary fluid flows in the elbow. For the second, the secondary fluid flow in the 90-degree bend was suppressed from the particle drag, thus the particles only …


Scenario-Based Strategic Planning For Future Civil Vertical Take-Off And Landing (Vtol) Transport, Woojin Choi, Steven Hampton Jan 2020

Scenario-Based Strategic Planning For Future Civil Vertical Take-Off And Landing (Vtol) Transport, Woojin Choi, Steven Hampton

Journal of Aviation/Aerospace Education & Research

Rapid evolvement of the vertical take-off and landing (VTOL) technology in conjunction with recent robust R&D has demonstrated the technical feasibility of the civil VTOL system as a short-haul mass transit mode. Its combined benefits of a helicopter and a turboprop into one aircraft is expected to become an effective remedy for congested air traffic and difficulties with airport expansions in the metropolitan areas along with the potential benefit to improve accessibility to population centers and remote areas where conventional aircraft cannot access.

In this study, based on a the Political, Economic, Social, Technological, Environmental, and Legal (PESTEL) factors and …


Evaluation Of 1-D And 2-D Hydraulic Models For Designing And Assessing Fullspan Stream Crossings, Alyssa Sachiko Virgil Jan 2020

Evaluation Of 1-D And 2-D Hydraulic Models For Designing And Assessing Fullspan Stream Crossings, Alyssa Sachiko Virgil

Cal Poly Humboldt theses and projects

This project compared design decisions and hydraulic analyses of full-span stream crossings using one- and two-dimensional (1-D and 2-D) hydraulic models. The project was initiated by the California Department of Transportation’s interest in moving from 1-D to 2-D hydraulic modeling and by the Federal Highways Administration’s support for adopting SRH-2D (Sedimentation and River Hydraulics-2D developed by the US Bureau of Reclamation) in Aquaveo, LLC’s Surface-water Modeling System as their standard design model. Two-dimensional hydraulic models calculate more detailed water depths and velocities than 1-D models, which can better identify fish passage conditions, areas of potential scour or deposition, and aquatic …


Sediment Yield In Salmon Creek After Decommissioning Logging Roads, Northern Humboldt County, California, Malia S B Gonzales Jan 2020

Sediment Yield In Salmon Creek After Decommissioning Logging Roads, Northern Humboldt County, California, Malia S B Gonzales

Cal Poly Humboldt theses and projects

Salmon Creek watershed is located in the Headwaters Forest Reserve in northern California and is known for the ecological value of its old-growth redwood forest, high biodiversity, and sensitive habitat for endangered species. The Bureau of Land Management primarily manages the Reserve. The land-use history of the Upper Salmon Creek watershed includes extensive timber harvest and road development. Watershed restoration in the Upper Salmon Creek watershed started in 2000 with the primary goal for the Reserve to protect and recover ecologic diversity and threatened native species. Since then, of the 23 miles, 13.5 miles of logging roads and 101 stream …


Electrification Of Domestic Hot Water To Aid The Integration Of Renewable Energy In The California Grid, Alejandro Cervantes Jan 2020

Electrification Of Domestic Hot Water To Aid The Integration Of Renewable Energy In The California Grid, Alejandro Cervantes

Cal Poly Humboldt theses and projects

Water heating in residential buildings, also known as domestic hot water (DHW), is the third largest use of energy after appliances and space conditioning. About 90% of the residential buildings in the state use natural gas fueled water heaters, 6% use electricity, and a small percent use liquefied petroleum gas (LPG) or solar water heaters. The current energy use associated with residential water heating is small relative to the total amount of energy consumption in the residential building sector, but it is still a contributor of greenhouse gas (GHG) emissions. Improving hot water systems can be beneficial for bill customer …


Pfas Removals And Increases In The Effluent Of Thirteen New Hampshire Wastewater Treatment Facilities Due To The Effects Of Biological Treatment Processes, Zachary P. Harvell Jan 2020

Pfas Removals And Increases In The Effluent Of Thirteen New Hampshire Wastewater Treatment Facilities Due To The Effects Of Biological Treatment Processes, Zachary P. Harvell

Honors Theses and Capstones

PROPOSAL/ABSTRACT:

Perfluoroalkyl substances, or PFAS, are an emerging contaminant of concern in environmental engineering. This group of chemicals has been used by manufacturers since the 1940s due to their desirable waterproofing qualities. They also have a high chemical stability at high temperatures, which makes treatment difficult. A large variety of manufactured items contain PFAS, such as fabrics and apparel, non-stick items, and food wrappers. Recently, these compounds have come under question due to studies supporting harmful health effects, such as low birthweight, cancer, thyroid hormone disruption, and a weakened immune system. Due to their chemical structure, PFAS compounds are difficult …


A Review On Investigating The Experimental Process For Partial Replacement Of Cement With Sugarcane Bagasse In The Construction Industry, Amany G. Micheal Prof., Rania Rushdy Moussa Ass. Prof., Nadin Magdy Dawoud Eng. Jan 2020

A Review On Investigating The Experimental Process For Partial Replacement Of Cement With Sugarcane Bagasse In The Construction Industry, Amany G. Micheal Prof., Rania Rushdy Moussa Ass. Prof., Nadin Magdy Dawoud Eng.

Architectural Engineering

In the last few decades there has been speedily increasing in the agriculture and industrial wastes. This causes many environmental issues and raises the potential to contaminate the natural resources of living such as water, air and soil. Recently, the amount of organic waste produced daily has been rising, while it is poorly managed. It is either burned or disposed improperly, which effect negatively the environment and public health. On the other hand, during the cement production process many wastes, and pollutants are generated which have major negative impacts on the environment. Cement is considered as a substantial constituent of …


Progressive Collapse Assessment Of Post-Tensioned Reinforced Concrete Flat Slab Structures Using Aem, Amgad Mahrous, Mariam Ehab, Hamed Hadhoud Jan 2020

Progressive Collapse Assessment Of Post-Tensioned Reinforced Concrete Flat Slab Structures Using Aem, Amgad Mahrous, Mariam Ehab, Hamed Hadhoud

Civil Engineering

Progressive collapse is defined as the failure of a primary vertical element of a structure, which may result in the failure of adjoining elements, consequently, leads to a partial or total collapse of the structure. Unified Facilities Criteria (UFC) and General Services Administration (GSA) guidelines used to assess the behavior of structures subjected to progressive collapse as a result of the loss of primary vertical support. For the current case study, numerical analysis is carried out for a typical ten-story reinforced concrete post-tensioned flat slab structure subjected to primary vertical element loss (corner column, edge column, internal column, edge shear …


Site-Specific Irrigation Management In A Sub-Humid Climate Using A Spatial Evapotranspiration Model With Satellite And Airborne Imagery, Sandeep Bhatti, Derek M. Heeren, J. Burdette Barker, Christopher M. U. Neale, Wayne Woldt, Mitchell S. Maguire, Daran Rudnick Jan 2020

Site-Specific Irrigation Management In A Sub-Humid Climate Using A Spatial Evapotranspiration Model With Satellite And Airborne Imagery, Sandeep Bhatti, Derek M. Heeren, J. Burdette Barker, Christopher M. U. Neale, Wayne Woldt, Mitchell S. Maguire, Daran Rudnick

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Variable Rate Irrigation (VRI) considers spatial variability in soil and plant characteristics to optimize irrigation management in agricultural fields. The advent of unmanned aircraft systems (UAS) creates an opportunity to utilize high-resolution (spatial and temporal) imagery into irrigation management due to decreasing costs, ease of operation, and reduction of regulatory constraints. This research aimed to evaluate the use of UAS data for VRI, and to quantify the potential of VRI in terms of relative crop and water response. Irrigation treatments were: (1) VRI using Landsat imagery (VRI-L), (2) VRI using UAS imagery (VRI-U), (3) uniform (U), and (4) rainfed (R). …


An Automated Seepage Meter For Streams And Lakes, D. Kip Solomon, Eric Humphrey, Troy E. Gilmore, David P. Genereux, Vitaly Zlotnik Jan 2020

An Automated Seepage Meter For Streams And Lakes, D. Kip Solomon, Eric Humphrey, Troy E. Gilmore, David P. Genereux, Vitaly Zlotnik

Department of Agricultural and Biological Systems Engineering: Faculty Publications

We describe a new automatic seepage meter for use in soft bottom streams and lakes. The meter utilizes a thin‐walled tube that is inserted into the streambed or lakebed. A hole in the side of the tube is fitted with an electric valve. Prior to the test, the valve is open and the water level inside the tube is the same as the water level outside the tube. The test starts with closure of the valve, and the water level inside the tube changes as it moves toward the equilibrium hydraulic head that exists at the bottom of the tube. …


Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi Jan 2020

Automatic Wheat Lodging Detection And Mapping In Aerial Imagery To Support High-Throughput Phenotyping And In-Season Crop Management, Biquan Zhao, Jiating Li, P. Stephen Baenziger, Vikas Belamkar, Yufeng Ge, Jian Zhang, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Latest advances in unmanned aerial vehicle (UAV) technology and convolutional neural networks (CNNs) allow us to detect crop lodging in a more precise and accurate way. However, the performance and generalization of a model capable of detecting lodging when the plants may show different spectral and morphological signatures have not been investigated much. This study investigated and compared the performance of models trained using aerial imagery collected at two growth stages of winter wheat with different canopy phenotypes. Specifically, three CNN-based models were trained with aerial imagery collected at early grain filling stage only, at physiological maturity only, and at …


Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez Jan 2020

Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez

Electronic Theses and Dissertations, 2020-2023

The need for proper management of bilgewater to meet discharge regulations (e.g., 15 ppm oil) has revealed the necessity to expand the current understanding of bilgewater emulsions. This study proposed to evaluate emulsion stability under various environmental conditions and to identify governing parameters for emulsion formation. The stabilizing properties of eight-commercial cleaners and two-neat surfactants were evaluated. In situ characterization techniques were used for monitoring emulsion stability. Additionally, a needle-type pH microsensor and fluorescence spectroscopy were used for analyzing mass transfer at the oil-water interface. Water quality of extracted bilgewater showed to highly vary between vessels (e.g., conductivity: 1.74 -- …


An Investigation Of Life Cycle Sustainability Implications Of Emerging Heavy-Duty Truck Technologies In The Age Of Autonomy, Burak Sen Jan 2020

An Investigation Of Life Cycle Sustainability Implications Of Emerging Heavy-Duty Truck Technologies In The Age Of Autonomy, Burak Sen

Electronic Theses and Dissertations, 2020-2023

Heavy-duty trucks (HDTs) play a central role in U.S. freight transportation, carrying most of the goods across the country. The projected increase in freight activity (e.g. truck-miles-traveled) raises concerns regarding the potential sustainability impacts of the U.S. freight industry, marking HDTs as an ideal domain for improving the sustainability performance of U.S. freight transportation. However, the transition to sustainable trucking is a challenging task, for which multiple sustainability objectives must be considered and addressed under a variety of emerging HDT technologies while composing a sustainable HDT fleet. To gain insights into the sustainability implications of emerging HDT technologies as well …


การปรับปรุงสะพานทางหลวงจากผลกระทบแผ่นดินไหวด้วยระบบแยกฐานและการเสริมค่าความหน่วงโดยใช้เหล็กเดือย, ยงศักดิ์ จิวะตระกูลธรรม Jan 2020

การปรับปรุงสะพานทางหลวงจากผลกระทบแผ่นดินไหวด้วยระบบแยกฐานและการเสริมค่าความหน่วงโดยใช้เหล็กเดือย, ยงศักดิ์ จิวะตระกูลธรรม

Chulalongkorn University Theses and Dissertations (Chula ETD)

การออกแบบโครงสร้างสะพานภายใต้แรงแผ่นดินไหวด้วยระบบแยกฐาน สามารถลดผลกระทบที่เกิดจากแรงกระทำได้เป็นอย่างดี แต่ในขณะเดียวกันกลับทำให้โครงสร้างสะพานส่วนบนเกิดการเคลื่อนตัวที่มากขึ้นเป็นผลให้เกิดการชนกันระหว่างชิ้นส่วน และเกิดการวิบัติจากระยะรองรับช่วงสะพานที่ไม่เพียงพอ งานวิจัยนี้มีวัตถุประสงค์ในการศึกษาผลตอบสนองของชิ้นส่วนโครงสร้างสะพานที่ถูกออกแบบด้วยระบบแยกฐานและใช้เหล็กเดือยช่วยในการสลายพลังงานและลดการเคลื่อนที่ของคาน ซึ่งจะทำการวิเคราะห์โครงสร้างด้วยวิธีการไฟไนต์อิลิเมนต์ โดยใช้โปรแกรม SAP2000 การศึกษาเลือกพิจารณาสะพานแบบคานคอนกรีตอัดแรงรูปตัวไอ มีความยาวช่วงเสา 20 เมตร ทั้งหมด 5 ช่วง มีการติดตั้งแผ่นยางรองคานสะพานเป็นอุปกรณ์แยกฐาน นอกจากนี้จะทำการคัดเลือกคลื่นแผ่นดินไหวให้สอดคล้องกับการสั่นไหวของพื้นดินที่เกิดขึ้นใน จังหวัดเชียงใหม่ ประเทศไทย หลังจากทำการสร้างแบบจำลองจะทำการวิเคราะห์โครงสร้างด้วยวิธีการวิเคราะห์การตอบสนองไม่เชิงเส้นแบบประวัติเวลา โดยจะทำการเปรียบเทียบผลการตอบสนองของโครงสร้างสะพานทั้งก่อนและหลังการปรับปรุงโดยใช้เหล็กเดือย ซึ่งจะพิจารณาในกรณีที่เพิ่มความหนาของแผ่นยางรองคานสะพานจากเดิมขนาด 20 เป็น 100 มิลลิเมตร และทำการติดตั้งเหล็กเดือยขนาดเส้นผ่านศูนย์กลาง 25 มิลลิเมตร เป็นอุปกรณ์ยึดรั้ง ผลการศึกษาพบว่าการเลือกปรับปรุงโดยการเลือกใช้เหล็กเดือยจำนวน 2 ชิ้น ติดตั้งในระนาบที่ยึดรั้งบริเวณจุดรองรับของโครงสร้างสะพานส่วนบนกับโครงสร้างสะพานส่วนล่าง ให้ผลการตอบสนองที่เหมาะสมมากกว่ากรณีก่อนการปรับปรุง โดยระยะการเคลื่อนตัวสูงสุดของคานรองรับแผ่นพื้นลดลงจาก 64 เป็น 51 มิลลิเมตร คิดเป็นร้อยละ 20 และยังช่วยลดผลการตอบสนองของโครงสร้างสะพานส่วนล่าง โดยเสาตอม่อเกิดการครากเพียงเล็กน้อย นอกจากนี้แรงเฉือนสูงสุดที่ฐานลดลงร้อยละ 22 เมื่อเทียบกับกรณีก่อนการปรับปรุงโครงสร้างสะพาน


การพัฒนาผนังสลายพลังงานแบบวิสโคอิลาสติก, ฐิติพงศ์ เจริญสุข Jan 2020

การพัฒนาผนังสลายพลังงานแบบวิสโคอิลาสติก, ฐิติพงศ์ เจริญสุข

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์ในการศึกษาพัฒนาผนังสลายพลังงานแบบวิสโคอิลาสติก (Viscoelastic wall dampers) ด้วยวัสดุ Asphalt (ยางมะตอย) และ Polyisobutene (PIB) แม้ว่าในปัจจุบันมีผู้ผลิตอุปกรณ์สลายพลังงานสำหรับอาคารเพื่อต้านทานแผ่นดินไหวและแรงลมจำหน่าย แต่มีราคาแพงเพราะต้องนำเข้าจากต่างประเทศ ทั้งมีค่าใช้จ่ายในการติดตั้งและบำรุงรักษาที่สูง นอกจากนั้นยังพบว่า ส่วนใหญ่มีรูปแบบที่กระทบต่อความสวยงามด้านสถาปัตยกรรม ในงานวิจัยนี้จึงพิจารณาถึงความเป็นไปได้ในการพัฒนาผนังสลายพลังงานแบบวิสโคอิลาสติกด้วยวัสดุที่มีราคาไม่แพง มีรูปแบบคล้ายผนังอาคารทั่วไปเพื่อไม่กระทบต่อความสวยงามของอาคาร โดยทำการพัฒนาแบบจำลองทางคณิตศาสตร์ของผนังสลายพลังงานจากการทดสอบชิ้นงานตัวอย่างขนาดย่อส่วนในห้องปฏิบัติการ ภายใต้แรงกระทำแบบวัฏจักร (Cyclic testing) ตามมาตรฐาน ASCE 7-16 ผลการทดลองแสดงให้เห็นว่าวัสดุ PIB มีคุณสมบัติในการสลายพลังงานที่ดี และมีเสถียรภาพภายใต้การเปลี่ยนแปลงอุณหภูมิ จึงนำแบบจำลองทางคณิตศาสตร์ของผนังสลายพลังงานชนิด PIB มาประมาณคุณสมบัติของผนังสลายพลังงานขนาดเท่าของจริง เพื่อเปรียบเทียบประสิทธิภาพในการสลายพลังงานกับผลิตภัณฑ์ผนังสลายพลังงานแบบหนืด (Viscous Wall Damper) ของต่างประเทศ ผลการศึกษาพบว่าผนังสลายพลังงานแบบวิสโคอิลาสติคที่พัฒนามีประสิทธิภาพในการสลายพลังงานดีกว่าผนังสลายพลังงานแบบหนืดอย่างมีนัยสำคัญ ทำให้สามารถลดขนาดและจำนวนผนังสลายพลังงานที่ต้องติดตั้งในอาคารได้ จึงเป็นอีกหนึ่งทางเลือกในการออกแบบต้านทานแผ่นดินไหวและแรงลมที่อาจประหยัดและมีประสิทธิภาพกว่าวิธีการปกติที่นิยมเพิ่มขนาดส่วนโครงสร้างให้มีกำลังหรือสติฟเนสมากขึ้น


Soil-Water-Energy Nexus Of Green Roofs, Katherine Ann Bartels Jan 2020

Soil-Water-Energy Nexus Of Green Roofs, Katherine Ann Bartels

Masters Theses

"As the urban landscape continues to sprawl into previously undeveloped land to accommodate population growth, the need to design cities that effectively manage urban stormwater is imperative for a sustainable future. Green roofs use rain-harvesting techniques to reduce urban stormwater discharge while simultaneously providing traditional roof services as well as several ecosystem services. However, green roof media design varies greatly among commercial applications, and little guidance is available to engineers when selecting the media for prospective green roofs. Efforts to maximize stormwater retention and enhance urban heat island mitigation capabilities of green roofs while concurrently reducing nutrient loading were examined …


Optical Fiber Based Integrity Test Of Civil Engineering Materials: Numerical Analysis, Ruoyu Zhong Jan 2020

Optical Fiber Based Integrity Test Of Civil Engineering Materials: Numerical Analysis, Ruoyu Zhong

Masters Theses

“Major advancement in Civil Engineering cannot be accomplished without the help of sensors. Among different types of sensors, fiber-optic sensor is known for its light weight, high accuracy, resolution, immunity to electromagnetic interference, and resistance to harsh environment. This research mainly focuses on fiber-optic sensor application on concrete structures as temperature sensor. Thermal Integrity Profiling (TIP) is a non-destructive integrity testing method which makes use of the hydration heat from the concrete curing process to detect defects within a drilled shaft. Any defect of concrete could result in a temperature anomaly in a drilled shaft. The accuracy of the current …


Feasibility Study On Novel Fire-Resistant Coating Materials, Anyou Zhu Jan 2020

Feasibility Study On Novel Fire-Resistant Coating Materials, Anyou Zhu

Masters Theses

“Over the past decades, wildfires in the United States have caused severe damage and property losses. The California Camp Fire in November 2018 caused 85 civilian fatalities and destroyed 18,793 structures. There is a need to enhance the fire resistance of structures and buildings. The primary purpose of this study was to develop innovative surface-bonded fire-resistant material that can be used as a wall coating with three primary features: (a) workability for application, (b) enough adhesion to the surface of the structure, (c) fire-resistant. This research developed mix designs of innovative fire-resistant coating materials including high-performance cement mortar (HPCM), geopolymer …


Lateral-Torsional Buckling Strength Of Two-Span Glass Fiber Reinforced Polymer Beams, Mojtaba B. Sirjani, Zia Razzaq Jan 2020

Lateral-Torsional Buckling Strength Of Two-Span Glass Fiber Reinforced Polymer Beams, Mojtaba B. Sirjani, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents the outcome of a study of two-span glass fiber reinforced polymer (GFRP) I-section beams susceptible to lateral-torsional buckling when subjected to gradually increasing concentrated vertical load(s) in the presence of two different types of lateral bracing schemes. It is found that loading one span results in a smaller buckling load as compared with the cases with loading in both spans regardless of the type of bracing scheme used. Also, the study shows that the addition of midspan braces for the GFRP beams results in up to 5.5 times increase in the buckling load capacity.


Seismic Response Mitigation Of Base-Isolated Buildings, Mohammad Hamayoun Stanikzai, Said Elias, Rajesh Rupakhety Jan 2020

Seismic Response Mitigation Of Base-Isolated Buildings, Mohammad Hamayoun Stanikzai, Said Elias, Rajesh Rupakhety

Civil & Environmental Engineering Faculty Publications

Earthquake response mitigation of a base-isolated (BI) building equipped with (i) a single tuned mass damper at the top of the building, (ii) multiple tuned mass dampers (MTMDs) at the top of the building, and (iii) MTMDs distributed on different floors of the building (d-MTMDs) is studied. The shear-type buildings are modeled by considering only one lateral degree of freedom (DOF) at the floor level. Numerical approach of Newmark's integration is adopted for solving the coupled, governing differential equations of motion of 5- and 10-story BI buildings with and without TMD schemes. A set of 40 earthquake ground motions, scaled …


Structural And Environmental Impact Of New-Generation Wide-Base Tires In New Brunswick, Canada, Izak M. Said, Jaime Hernandez, Seunggu Kang, Imad L. Al-Qadi Jan 2020

Structural And Environmental Impact Of New-Generation Wide-Base Tires In New Brunswick, Canada, Izak M. Said, Jaime Hernandez, Seunggu Kang, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The loading and environmental impacts of new-generation wide-base tires (NG-WBT) and dual tire assemblies (DTA) on typical asphalt concrete (AC) pavement sections of New Brunswick, Canada were evaluated using finite element method (FEM) analysis and life-cycle assessment. The impact of steering wheel was not considered in this study. The analysis considered realistic material models and loading conditions (i.e. AC viscoelastic characteristics and measured three-dimensional nonuniform tire–pavement contact loads). Predicted critical pavement responses were used in transfer functions to determine potential pavement damage. The NG-WBT loading resulted in greater critical pavement responses compared to that of DTA, especially near the surface …


Forecasting The Short-Term Value Of Wind Power For Risk-Aware Bidding Strategies In Single-Imbalance Price Electricity Markets, Gianni Goretti Jan 2020

Forecasting The Short-Term Value Of Wind Power For Risk-Aware Bidding Strategies In Single-Imbalance Price Electricity Markets, Gianni Goretti

Doctoral

The participation of wind energy in electricity markets and strategic bidding in the day-ahead market has been investigated with growing interest in recent years. However, markets adopting a single-price imbalance settlement where participants can increase their profits if they help to put the system back into balance have received very limited attention in the academic literature. In this thesis, new probabilistic models forecasting the short-term value of wind power are developed and their use in bidding in these types of markets is investigated. The proposed strategies are designed for participants who want to bid strategically in the day-ahead market to …