Structural Engineering Commons^™

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Reduction Of Embodied Carbon In Buildings Through Use Of Low Carbon Strategies And Standardization And Enforcement Of Life Cycle Assessment, Bhargavi Sai Sudhakar

Master's Projects and Capstones

The building and construction industry is energy intensive and as of 2021, this industry is responsible for 37% of the total global greenhouse gas emissions. In previous studies of conventional buildings, the operational energy of a building contributed to 80% and the embodied energy contributed to 20% of the total life cycle energy. With increase in policies and standards that focus on reducing the operational energy, low energy and certified green buildings have emerged where the operational energy has considerably reduced. The relative and absolute share of embodied energy in these energy efficient buildings have increased due to excessive use …

Energy Efficiency Retrofit And Decarbonization Of Old And Historic Buildings In California, Daria Nikolaeva

Master's Projects and Capstones

Buildings are responsible for almost 40% of total global greenhouse gas emissions and the retrofitting of existing buildings is an essential part of solving the problem. About 75% of buildings in Californian were constructed before the first energy-efficiency building code was adopted in 1978. Old buildings are inefficient, responsible for large carbon footprints and must be retrofitted to stay on track with the state's climate targets. However, current policies do not require substantial changes and tend to favor historic preservation over energy efficiency, missing improvement opportunities. Recognizing the significance of carbon intensity, the 2019 California Energy Efficiency Action Plan shifted …

Evaluating Arkansas Weathering Steel Bridge Performance, Yessenia Gonzalez

Graduate Theses and Dissertations

Weathering steel enhances corrosion-resistant steel features over conventional steel when a patina properly forms on the weathering steel surface. Weathering steel is a low carbon steel of less than 0.3% carbon by weight and has a chemical composition including other alloying elements such as nickel, copper, and chromium that develops a patina. The patina is a dense protective oxide film layer that develops on the steel member surface. The patina defends the steel from corrosion by preventing moisture, oxygen, and contaminant penetration. However, long periods of moisture and deicing chemicals applied during wet wintry conditions hinder proper patina formation. Without …

Improving Building Cfd Peak Pressure Computation Using Les With A Focus On Inflow Turbulence Methods And Grid Spacing Size., Zahra Mansouri

Graduate Theses and Dissertations

Structural failures by extreme winds often leads to economic losses and even deaths. Proper design of buildings requires accurate estimation of wind loads to prevent structural damage. Using routine guidelines generally leads to the underestimation of buildings’ peak pressures, in which most failures occur. To estimate wind loads more accurately three different methods (i.e., field measurement, wind tunnel (WT), and computational fluid dynamics (CFD)) are in use. A well-validated CFD provides more flow field details at lower costs compared to field measurements and WT. As strong winds are extremely turbulent, the effects of turbulence in wind should be incorporated into …

A Study On Early Age Properties Of Concrete For Precast And 3d Printing, Debalina Ghosh

Doctoral Dissertations

Concrete is the second-most consumed material, leading the global Portland cement production of 4.1 billion tons in 2020 and 5-8% of global Carbon dioxide (CO₂) emission annually. As with any other material and practice, the construction industry is also ever-changing to meet market demand, evolving technology, and resource limitation. In the case of concrete construction, one of the main concerns is the lack of automation. In the last few decades, some new construction methods have risen to address this concern. Some of these economic and successful practices are precast construction, self-compacting concrete (SCC), and 3D printing of concrete(3DPC). …

Performance Based Design And Machine Learning In Structural Fire Engineering: A Case For Masonry, Deanna Craig

All Theses

The volatile and extreme nature of fire makes structural fire engineering unique in that the load actions dictating design are intense but not geographically or seasonally bound. Simply, fire can break out anywhere, at any time, and for any number of reasons. Despite the apparent need, fire design of structures still relies on expensive fire tests, complex finite element simulations, and outdated procedures with little room for innovation. This thesis will make a case for adopting the principles of performance-based design and machine learning in structural fire engineering to simplify the process and promote the consideration of fire in all …

Flexural Bond Strength Of Masonry Assemblies With Lightweight Grout, Benjamin L. Hiner

All Theses

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench …

Flexural Testing Of Precast Reinforced Concrete Bridge Slabs, Evaluation Of Deterioration And Strengthening Applications, Alyssa Leaman

All Theses

This thesis investigates the strength of flat precast concrete slabs that were taken from decommissioned South Carolina bridges. The specimens tested spanned 14 ft (4.3 m) or 15 ft (4.6 m), were 5 ft (1.5 m) or 5.5 ft (1.7 m) wide, and 8.25 in (210 mm) thick. In South Carolina, there are approximately 3000 similar bridges that use these slab members. Testing was conducted to determine the flexural capacity of “typical” slabs and the residual strength of slabs having visible deterioration of both the rebar and the concrete. For the slabs that were load rated below the new standards, …

Schematic Design And Peer Review Of Gayaza Medical Center And Walk-In Clinic, Abigail Coffing, Alexis Buhr

Architectural Engineering

This report outlines the structural portion of the work done for the Gayaza Medical Center in Kampala, Uganda. This project was funded by HIINGA, an impact fund doing work in Eastern Africa, who tasked an interdisciplinary group of Cal Poly students with developing a preliminary design for the the medical center. The team consisted of Annebel van der Meulen (architecture), Abigail Coffing and Alexis Buhr (structural), and Arley Landis and Brett Shank (construction management). After completing the initial design, the structural team at Cal Poly rejoined the project the following quarter to do a peer analysis of the finalized structural …

Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon

Architectural Engineering

Precious Plastics, a Netherlands based company, created an open source project that can be used to create different objects from recycled plastics. The San Luis Obispo area has a large amount of recyclable plastic that is being treated as trash, adding to the pollution of the ocean and the air. This project is to determine the necessary steps to create plastic building blocks, using the Precious Plastic process, as a construction material for low-income, temporary housing. This report covers the process that was used to build two of the machines that will be used to create the bricks. This requires …

A Multi-Criteria Ranking System For Prioritizing Maintenance Of Levee Systems In Arkansas, Nguyen Danh Phan

Graduate Theses and Dissertations

There are 208,009 properties in Arkansas that have more than a 26% chance of being severely affected by flooding over the next 30 years, which represents 13% of all properties in the state. A levee system is designed to reduce the flooding risk for urban and rural communities; however, most of the state's levees have been significantly outdated or built with engineering standards less rigorous than current best practices. The Levee Safety Action Classification (LSAC), as recorded in the National Levee Database (NLD), communicates the risk associated with living behind a particular levee and assists local, state, and federal stakeholders …

Design Of Stick-Framed Wood Roofs Under Extreme Wind Loads, Caspar Bain

Electronic Thesis and Dissertation Repository

Light-frame wood construction comprises nearly 90% of the housing industry in
Canada and the United States. The roofs of these houses can be constructed either
entirely on site or using prefabricated trusses. Assembling the roof structure on site,
otherwise known as stick-framing, is a framing technique with current code guidelines
that are based on past practice and limited consideration of wind loads. This makes
these roof structures susceptible to failure in high-speed wind events, such as tornadoes. Around 90% of all tornadoes in Canada fall in or below the EF-2 category,
making it a possible target for design of wood-frame …

An Explicit Model For Simplified Flutter Analysis Of Long-Span Bridges, Tibebu Hunegn Birhane

Electronic Thesis and Dissertation Repository

The collapse of the First Tacoma Bridge in 1940 at a wind speed of about 18m/s triggered the need to recognize aerodynamic stability as a design constraint for long-span bridges. The advancement in understanding and modeling of dynamic wind effects has played a significant role in the realization of long-span bridges with a clear span of up to 2 km. However, the need to span longer, the risk of windstorms exceeding the strongest recorded in the past, and consequently, the quest for optimized design solutions continue to evolve.

A rigorous nature of aerodynamic stability analysis techniques poses a challenge to …

Multimodal Imaging Of Structural Concrete Using Image Fusion And Deep Learning, Sina Mehdinia

Dissertations and Theses

Concrete structures may be exposed to a variety of loads and environments during their service life. Non-destructive testing (NDT) techniques can be helpful in evaluating the condition of a structure. Imaging provides a visual representation of the interior of concrete and its condition non-destructively. Ground penetrating radar (GPR) and ultrasonic echo array (UEA) using electromagnetic and stress waves, respectively, provide the data that can be used to reconstruct an image. In this PhD dissertation, image reconstruction and fusion algorithms, simulation, and a deep learning model were investigated with the goal to lay the foundation for enhanced imaging applications for concrete. …

Incorporating Geopolymer Binders To Fully Utilize Recycled Concrete Aggregates, Matthew Upshaw

LSU Doctoral Dissertations

This study aims to develop a geopolymer concrete binder that will yield desirable strength and durability characteristics when applied to recycled aggregate concrete. In order to achieve this, a geopolymer binder consisting of a metakaolin-silica fume aluminosilicate source material blend activated by potassium-based alkaline solutions is developed and used in place of ordinary Portland cement (OPC) with four different levels of recycled aggregate replacement ratios. The properties of these concretes were analyzed and compared with the properties of OPC concretes produced with the same replacement ratio levels. The results showed that the geopolymer recycled aggregate concrete (GRAC) achieved greater than …

Structural Steel Connection Design For Tensile Rupture By Advanced Inelastic Analysis, Kaylalyn H. Truman-Jarrell

Masters Theses

Connections are critical in structural steel buildings for transferring forces from member to member. Connections must be designed for safety and to ensure they serve their intended function. Many resources are available to engineers designing connections with common configurations and loads. But connection designers often encounter configurations and loading conditions for which there is little guidance. In these cases, design by advanced inelastic analysis can be advantageous. IDEA StatiCa is a steel connection design software for design by advanced inelastic analysis. In this software, some limit states are captured in the same manner as standard strength equations, while others are …

Crack Control And Bond Performance Of Alternative Coated Reinforcements In Concrete, Sachin Sreedhara

All Dissertations

Concrete cracking in structures is a ubiquitous problem which can lead to the deterioration of the structure. Other than affecting the strength aspect of a structure, cracking impacts the serviceability criteria as well. Although cracking phenomenon in any structure is highly inevitable, it has to be minimized in order to maintain a structure’s life effectively. Cracking in reinforced concrete structures is related to the bond strength developed between the bar and the concrete. It also depends on an ability of the bar to resist the stresses due to shrinkage to minimize the crack. Another important aspect is the resistance offered …

Tessellated Structural-Architectural Systems: Experimental Testing And Interdisciplinary Student Projects, Grace F. Crocker

All Dissertations

This dissertation discusses a new structural system called a Tessellated Structural-Architectural (TeSA) system. These TeSA systems utilize architecturally appealing tessellations in load-bearing structures comprised of interlocking tiles in a pattern. This dissertation focuses on the design, construction, and structural behavior of these TeSA systems, as well as their value as an interdisciplinary learning tool.

This dissertation has 4 research objectives: 1) Demonstrate the fabrication and construction of a precast reinforced concrete (RC) TeSA shear wall system; 2) Measure the structural performance of the RC TeSA shear wall system; 3) Compare simplified shear and flexural analysis methods for RC TeSA shear …

Rapidly Deployable Structures For Disaster Relief And Military Use, Jayson Leonard

All Theses

Rapidly deployable structures currently play a vital role in the recovery aspect of disaster-stricken areas and the safety of military personnel in hostile zones. More recently there has also been a need for the structures to deal with unforeseen disruptions caused by the COVID pandemic, such as COVID testing centers or backyard pop-up offices. These structures could be used in different environments and serve many other purposes. Along with the structural performance of these shelters, they need to integrate into systems set in place effortlessly. For that reason, four key factors were taken into consideration, namely (1) deployability (how difficult …

Development Of Ultra High Performance Composite Impact Panels Using Emaa, Jeffrey Hollstein

Electronic Theses and Dissertations

UHPC with the addition of fibers is recognized for its increased impact resistance compared to typical strength concrete. To further increase the resilience, recent studies have been conducted to reinforce the UHPC with CFRTP on the front and rear face to create sandwich panels. These studies used PETg/E-glass CFRTP bonded to the UHPC using EMAA (Surlyn) in a stamp thermoforming process. Impact tests conducted on these panels have shown that delamination has been the initial and detrimental failure to the sandwich composite. Increasing the composites resistance to debonding will increase the impact energy required to debond the composite. In this …

Inspection Of Flexible Fillers In Post-Tensioned Bridges, Carley Gonzalez

Doctoral Dissertations and Master's Theses

The Florida Department of Transportation (FDOT) is currently pushing toward the use of flexible fillers (FF) in new post-tensioned (PT) bridges. Flexible fillers have several advantages compared to the currently used cementitious grouts (CG) and can offer longer-lasting structures by providing better corrosion protection and allowing for replaceable tendons, which reduces the overall maintenance costs over the structure’s lifespan. Due to these fillers being used in new bridges, FDOT needs effective nondestructive evaluation (NDE) methods to employ in their biennial inspections. There are currently numerous NDE methods available to inspectors that have been used to identify defects in PT bridges …

Numerical And Experimental Investigation Of Machinery Isolation Featuring Gap-Type Nonlinear Rotational Inertial Mechanisms For Marine Applications, Alexandra C. Shafer

Masters Theses

Transmitted noise and vibration from equipment and machinery is an ongoing and serious priority onboard marine vessels as noise and vibrations interfere with system operations and can compromise the functionality of the vessel. Vibration isolation systems have been widely studied for civil and mechanical applications because of the damage that can occur from extreme vibrations and excessive motion. Conventional vibration isolation systems often include components such as springs and dampers in the isolation layer, but researchers have begun to incorporate other devices including, linear rotational inertial mechanisms (RIMs), often known as inerters, to enhance traditional vibration isolation systems. The inerter …

The Evacuation Simulation Of Wheelchair Users In A Building Fire: An Initial Dynamic Characterization Of Structural Egress Components, Haley Hostetter

All Theses

People with disabilities are one of the most vulnerable groups involved in building fires. According to the U.S. Fire Administration, in the United States alone, an estimated 700 home fires involve people with physical disabilities each year while over 1700 involve those with mental health disorders. Despite this, the current body of literature shows few studies focused on the evacuation of disabled people. This is a direct result of past and present social injustice on people with disabilities and has resulted in high injury and death rates during fires. To combat this, enrich the literature, and improve their experiences in …

Effect Of Varying Amounts Of Sandstone On The Performance Of Asphalt Mixtures In Arkansas, David Murphy

Graduate Theses and Dissertations

There are many different species and subspecies of aggregate used across the state of Arkansas, and the rest the country. However, it cannot be presumed that the amount and type of these aggregates will be compatible with the commonly used asphalt binder of an area; this can lead to performance issues and premature pavement damage. It has been suspected in Arkansas that an excessive amount of sandstone in asphalt mixtures may be a culprit of some of these premature pavement damage issues, especially regarding the moisture susceptibility of a pavement. This study aimed to analyze the performance effects of using …

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …

Investigations Into Flange Surface Friction Effects On Shear Stud Load Transfer In Composite Bridge Girders, Callie Clark

Graduate Theses and Dissertations

Composite bridge behavior is commonly achieved through headed shear studs welded tothe steel girder flange and embedded in the concrete deck. Current AASHTO provisions for estimating demands on shear studs during service-level loading consider only bearing load transfer, neglecting adhesion bonding and friction load transfer between the concrete deck and girder flange. Quantifying alternative load transfer mechanisms across the steel-concrete interface may result in improved steel bridge economy by reducing the number of studs required in a composite girder design. This study investigates the effects of flange surface friction (considering various coatings) on resulting stud demands using both experimental testing …

Flexural Behaviour Of Concrete Beams With High Strength Reinforcement, Sohaib Akbar

Electronic Thesis and Dissertation Repository

Using High Strength Reinforcement (HSR) in concrete construction allows steel volumes to be reduced, and economies to be realized. CSA Standard A23.3:19 “Design of Concrete Structures” limits the maximum yield strength for design to 500 MPa. This thesis investigates the flexural behavior of concrete beams reinforced with HSR to assess whether current code provisions are appropriate. Curvature ductility ratios are calculated for cross-sections with varying concrete compressive strengths, and reinforcement types and quantities. The effects of utilizing HSR on extreme fibre concrete compressive strains at Ultimate Limit State (ULS), moment redistribution at ULS, and deflections at Serviceability Limit States, are …

Simulation Of Non-Homogeneous Wind Processes, Comparison Between Numerical And Experimental Model Of A Bridge, Héctor Hernández Landero

Electronic Thesis and Dissertation Repository

The scaled aerodynamic model of a bridge is often tested in the boundary layer wind tunnel laboratory (BLWTL). In this study a numerical model of the Baluarte Bridge subjected to wind loading is investigated. The scaled full bridge aerodynamic model was previously studied at the University of Western Ontario, Canada. For the numerical model a finite element model (FEM) is implemented, and the characterization of the buffeting forces are considered on the frequency and time domain. In the former case, the so-called pseudo excitation method is used to characterize the wind load, while in the latter the spectral representation method …

Ultrasonic Ndt Methods For The Evaluation Of Post-Tensioned Systems With Flexible Fillers, Denis Mcdonald

Doctoral Dissertations and Master's Theses

Non-destructive evaluation of post-tensioned structures with flexible fillers is desperately needed due to their rapid implementation in the State of Florida, primarily in roadway structures. This study provides an overview of existing evaluation methods for traditional post-tensioned structures with cementitious grouts and further explores two promising methods to be applied to flexible filler systems. The first method, diffuse ultrasound spectroscopy, indirectly evaluates posttensioned structures by quantifying the severity of microcracking in the structure. Microcrack detection is accomplished by processing received waveforms generated with a pitch-catch transducer configuration. The second method, coda-wave interferometry, measures the velocity variation at the tail end …