Structural Engineering Commons^™

Bayesian Model Updating Of Structural Parameters Using Temperature Variation Data., Ujjwal Adhikari

Electronic Theses and Dissertations

Physical digital twins have now emerged as a technology in structural health monitoring and other domains of structural modeling. A Finite Element Model can be a tool for digital twin technology in conjunction with measured physical data. Developing an accurate digital model requires the integration of various parameters to replicate the real structure; however, temperature is dynamically changing, resulting in difficulty in the identification of structural parameters. Typically, temperature is considered noise or filtered out. Limited research has addressed the physics-based model using temperature variation related to structural modal properties. Finite Element Model Updating (FEMU) is a typical inverse problem-solving …

Effects Of Peel Angle And Strain Rate On The Bond Between Frcm Composite And Concrete Substrate, Lucas Robert Gervais

Electronic Theses and Dissertations

Fiber-reinforced cementitious matrix (FRCM) composites have gained increasing attention for the rehabilitation and strengthening of concrete and masonry structures due to their favorable mechanical properties, compatibility with existing substrates, and ease of application. The effectiveness of any strengthening procedure depends on the quality of the bond between the external reinforcement and the substrate, ensuring efficient stress transfer and enabling the system to reach its ultimate capacity without premature debonding. While research has focused on the bond performance of FRCM systems under pure shear loading and quasi-static, low strain rate conditions, the effects of mixed-mode loading and high strain rates representative …

Performance And Durability Assessment Of Concrete Bridge Deck Sealants, Bipin Adhikari

Electronic Theses and Dissertations

No abstract provided.

Electronic Waste As Synthetic Aggregate For Portland Cement Concrete, Md Shafaul Islam

Electronic Theses and Dissertations

Lightweight concrete has grown in popularity in the building industry in recent years. Due to its environmental and economic benefits, the construction sector favors using lightweight concrete in applications allowed by the technical specifications. On the other hand, electronics waste (e-waste) is the world’s most rapidly growing waste problem. Given the scale and the volume of global concrete construction, incorporating e-waste as a lightweight concrete construction material can potentially reduce sending electronic waste to landfills, which is an environmental benefit. Additionally, it will help with saving the consumption of virgin aggregates. This study was undertaken to determine the feasibility of …

Repairable Precast Bridge Bents For Seismic Events, Kallan Hart

Electronic Theses and Dissertations

Concrete bridge columns are designed to withstand earthquakes by undergoing large displacements. Current seismic bridge codes guarantee collapse prevention, but damage to concrete and longitudinal reinforcement often requires demolition of the structure. Repairable detailing and advanced bridge construction connections may be utilized in concrete bridge columns to allow for quick construction as well as replacement of damaged reinforcement after an earthquake. This detailing may be an attractive alternative to bridge owners to reduce construction and replacement costs as well as ensure the functionality of critical routes after an earthquake. Three repairable precast bridge columns with exposed longitudinal reinforcement were tested …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Mechanically Spliced Precast Bridge Columns, Ted Sjurseth

Electronic Theses and Dissertations

Mechanical bar splices provide an alternative to the traditional method of lap splicing to achieve reinforcement bar continuity in reinforced concrete. Even though mechanical bar splices can be used as new precast column connections to accelerate the bridge construction (ABC), The use of bar couplers in the plastic hinge region of bridge columns is prohibited by the current US codes since the effects of bar couplers on the seismic behavior of columns is not fully investigated. A bridge column including precast columns with couplers located in a high seismic region must be designed to handle large inelastic lateral deformations. The …

Seismic Performance Of Mechanically Spliced Precast Bridge Columns With New Couplers, Evan Greeneway

Electronic Theses and Dissertations

Lap splicing is not always the most economical or practical approach to achieve reinforcement bar continuity. Mechanical bar splices, or bar couplers, are one alternative that may be far more practical. Currently, the US codes do not allow for the use of bar couplers in the plastic hinge region for RC members in areas of high seismic activity. There has not been enough research into the couplers behavior when subjected to significant inelastic lateral deformations. The Lohr Structures Laboratory was used to conduct an experimental study on campus of South Dakota State University to evaluate the seismic performance of mechanically …

Seismic Performance Of Mechanically Spliced Bridge Columns Through Analytical Studies, Mathew Ray Lavoy

Electronic Theses and Dissertations

Reinforcement continuity in concrete members is traditionally achieved through lap splicing. Mechanical bar splices are an alternative to traditional lap splices. Mechanical bar splices utilize mechanical devices known as bar coupler to connect the ends of reinforcing bars. Bar couplers are common in accelerated bridge construction applications at non-critical members but are not allowed in the plastic hinge region of bridge columns probably due to a lack of knowledge on how they affect seismic performance of columns. A comprehensive analytical study was carried out to determine how bar couplers used at the base of bridge columns affect: 1) column lateral …

Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani

Electronic Theses and Dissertations

Recently, Carbon Nanotubes (CNTs) are drawing considerable attention of researchers for reinforcing cementitious materials due to their excellent mechanical properties and high aspect ratio (length-to-diameter ratio). However, CNTs might not disperse well within the cement matrix, resulting in little improvement or even degradation of concrete properties. The uncertainty in producing the consistent results in different studies might be attributed to multiple interactions between the experimental variables affecting the nanotube dispersion and the final properties of CNT-cement nanocomposites. Therefore, this research mainly focused on proposing equations that can reliably capture these interactions in order to correlate CNT dispersion with the mechanical …

Investigation Of Flexural Behavior Of Steel Fiber Reinforced Concrete And Steel Fiber Orientation Control During Construction, Maria Kolisnichenko

Electronic Theses and Dissertations

Concrete is the most widely used construction material in the world, and its consumption has been increasing. The main benefits of concrete include its durability, availability of the components, and great strength in compression. Despite all these advantages, however, concrete is a brittle material with a relatively low tensile strength and deformation capacity. It is, therefore, vulnerable to cracking under tension, which can lead to sudden catastrophic failures of concrete structures. In order to control and reduce cracking, reinforcement of concrete is necessary.

The most commonly used reinforcement technique in structural application is the use of deformed steel bars. However, …

Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano

Electronic Theses and Dissertations

For this thesis, a study was completed on two different structures on the UCF Orlando campus through the use of both structural plans and point cloud technology. The results sought to understand the viability of point cloud technology as an accurate tool for the static and dynamic modal analysis of existing structures. For static analysis, a portion of the framing of Spectrum Stadium was rendered, modeled, analyzed and compared to a previous case study. The results emphasized how different users can render dissimilar member sizes and lengths due to human judgment on point cloud visuals. The study also found that …

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

Electronic Theses and Dissertations

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

Field And Numerical Study For Deteriorating Precast Double-Tee Girder Bridges, Brian Kidd

Electronic Theses and Dissertations

Two deteriorating DT bridges in South Dakota, both over 30-years old, were field tested with a static and dynamic load. From the recorded strain values, the liveload distribution factors (LLDFs) and dynamic load allowance (IM) factors were calculated. The AASHTO LRFD and AASHTO Standard Specifications were compared with the field LLDFs and IMs. It was determined that the AASHTO LRFD Specifications were conservative for deteriorating DT girder bridges, with two exceptions. The AASHTO Standard codified LLDFs were significantly higher than the field LLDFs in all cases. The AASHTO LRFD and AASHTO Standard specifications were conservative when calculating the IM factors …

Repairable Precast Buildings And Bridges, Abdullah Boudaqa

Electronic Theses and Dissertations

A new moment-resisting precast connection is developed in the present work through experimental and analytical studies to accelerate construction of bridges and buildings, to improve their seismic performance, and to quickly repair them through replacement of exposed reinforcement. The new precast joint detailing incorporates (1) detachable external reinforcing steel bars restrained against buckling, which is referred to as buckling restrained reinforcement (BRR), to develop plastic bending moments, (2) a steel pipe connecting the precast members through a pin connection to resist plastic shear forces, and (3) detachable mechanical bar splices to assemble and disassemble BRR at any time specifically after …

Evaluation Of The Effect Of Tack Coat Type, Application Rate, And Surface Type On Interlayer Shear Strength, Chamika Prashan Dharmarathna

Electronic Theses and Dissertations

Tack coat is an asphaltic material applied between asphalt pavement layers. Since pavement is a multilayered structure, it is highly important to make proper bond between the layers to achieve a monolithic behavior. Hence, inadequate bond due to application of inadequate amount of tack coat may lead to poor structural behavior and premature failure. Also, applying excessive amount of tack coat may lead to layer slippage and binder migration. Therefore, it is highly important to apply an optimum amount of tack coat between layers. Over the past decades several studies have been conducted to determine the optimum tack coat application …

Methodology For Load Rating Double-Tee Girder Bridges, Sandip Rimal

Electronic Theses and Dissertations

The most common type of bridge on South Dakota (SD) local roads is precast prestressed double-tee (DT) girders. More than 700 DT bridges are currently in-service in SD. Structural detailing, aging, traffic volume, and environmental conditions affect the structural performance, integrity, and capacity of DT bridges. When a bridge is affected by one or more of the aforementioned parameters, the estimation of the bridge safe live loads is necessary to ensure the safety of the traveling public and to prevent excessive bridge damage and collapse. Load rating of damaged bridges is challenging mainly because of a lack of information regarding …

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 …

Non-Contact Based Structural Damage Assessment Using Stochastic Subspace Identification And Finite Element Model Updating., Li Yang

Electronic Theses and Dissertations

This research proposed and verified an innovative method to identify and locate structural damage using only the response of operational vibration, that is the displacement acquired by a non-contact optical method. The most efficient and economical way to detect damage within the structure is to monitor its structural health while in operation. However, the uncertainties and the randomness of ambient vibrations due to the operation and environments cause a challenge in conducting the operational analysis. Current technology limits the ability to collect data on the properties of the structure without the interruption of operation. Frequencies and mode shapes have been …

Effects Of Mechanical Bar Splices On Seismic Performance Of Reinforced Concrete Buildings, Abdullah Al Hashib

Electronic Theses and Dissertations

Mechanical bar splices, which are commonly referred to as couplers, are currently used in reinforced concrete structures to directly connect steel bars in lieu of conventional lap splicing. With proper detailing, couplers can be utilized to connect precast beams and columns to accelerate the construction. However, the experimental and analytical studies regarding their effect on the performance of RC moment-resisting frames (MRFs) are scarce. Current ACI 318 restricts the use of couplers in plastic hinge regions of special moment-resisting frames (SMRFs). Nevertheless, they can be incorporated at any location of the intermediate and ordinary MRFs. The seismic performance of RC …

Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik

Electronic Theses and Dissertations

Stadiums, pedestrian bridges, dance floors, and concert halls are distinct from other civil engineering structures due to several challenges in their design and dynamic behavior. These challenges originate from the flexible inherent nature of these structures coupled with human interactions in the form of loading. The investigations in past literature on this topic clearly state that the design of flexible structures can be improved with better load modeling strategies acquired with reliable load quantification, a deeper understanding of structural response, generation of simple and efficient human-structure interaction models and new measurement and assessment criteria for acceptable vibration levels. In contribution …

Site Specific Sinkhole Risk Assessment In Central Florida Using Cone Penetrometer Testing, Ryan Shamet

Electronic Theses and Dissertations

As Florida's population is expanding and greater fluctuations in groundwater levels are being recorded, Central Florida has been experiencing a higher frequency of sinkhole occurrences than ever before in recorded history. Sinkholes in Central Florida are formed by a combination of bedrock weathering and overburden soil erosion due to the groundwater recharge and are a part of Florida's past and future geology. The initial stage of a sinkhole is referred to as soil raveling and is the most effective time to perform soil improvement measures, such as grouting, to mitigate further expansion of a subterranean void. Subsurface exploration tests, commonly …

Uav-Based Bridge Inspection And Computational Simulations, Luis Duque

Electronic Theses and Dissertations

The use of Unmanned Aerial Vehicles (UAV), commonly known as drones, has significantly increased in the field of civil engineering due to the poor condition of the United States’ infrastructure. The American Society of Civil Engineers (ASCE) recently reported that more than 9.1% of the United States’ bridges were structurally deficient and required attention and maintenance to ensure appropriate structural performance. Meanwhile, current practices are expensive and unsafe for bridge inspectors, requiring innovative and safer methods for the study of bridges. The goal of this paper was to identify better techniques to not only inspect, quantify, and determine the effect …

Precast Full-Depth Deck Panels Supported On Inverted Bulb-Tee Bridge Girders, Michael James Mingo

Electronic Theses and Dissertations

The South Dakota Department of Transportation (SDDOT) currently uses precast double-tee bridge deck systems for many of its county bridges because they are economical and fast in construction. Current bridges are designed for a service life of 75 years. However, many double-tee girder bridges are deteriorating and some need total replacement after 40 years in service. Furthermore, the double-tee bridge system only has one supplier in South Dakota. Alternative durable precast or prefabricated bridge systems are needed to provide more options to local governments when designing a new bridge. Different alternatives will also give local governments more flexibility to select …

Sinkhole Monitoring Using Groundwater Table Data, Ton Tu

Electronic Theses and Dissertations

Florida might be one of the most sinkhole-active areas on the earth. Due to its unpredictability and significance of occurrence, the development of sinkhole monitoring techniques is imperative to minimize sinkhole-induced hazards. Several methods have been used to evaluate sinkhole risks, including destructive methods, such as Standard Penetrating Tests (SPT) and Cone Penetrating Tests (CPT), geophysical method, and sensor-based groundwater monitoring method. However, few studies are available for comprehensive understanding of spatiotemporal sinkhole mechanism by combining different exploration methods under realistic experimental conditions. The objective of this study is to understand spatiotemporal sinkhole mechanism, using SPT, CPT, ground penetrating radar …

Evaluation Of Strength And Hydraulic Properties Of Buried Pipe Systems Used For Stormwater Harvesting, Mario Samson Mena

Electronic Theses and Dissertations

Water scarcity has been identified as a global issue. Both water harvesting and an efficient water piping system are some of the important factors to meet the water demand. In this study, high-density polyethylene (HDPE) pipes used as an underground storage was evaluated and a Microsoft EXCEL based model was developed, called PIPE-R Model. To study the structural integrity of the pipes, laboratory and field testing were conducted. For the water harvesting, UCF Stormwater Management Academy designed an EXCEL based model to simulate the system's performance to store and redistribute water for an average year. The purpose of PIPE-R Model …

Damage Detection Methodologies For Structural Health Monitoring Of Thin-Walled Pressure Vessels, Arturo Modesto

Electronic Theses and Dissertations

There is a need in exploring structural health monitoring technologies for the composite structures particularly aged Composite Overwrapped Pressure Vessels (COPVs) for the current and future implementation of COPVs for space missions. In this study, the research was conducted in collaboration with NASA Kennedy Space Center and also NASA Marshall Space and Flight Center engineers. COPVs have been used to store inert gases like helium (for propulsion) and nitrogen (for life support) under varying degrees of pressure onboard the orbiter since the beginning of the Space Shuttle Program. After the Columbia accident, the COPVs were re-examined and different studies (e.g. …

Characterization Of Dynamic Structures Using Parametric And Non-Parametric System Identification Methods, Ayad Al Rumaithi

Electronic Theses and Dissertations

The effects of soil-foundation-structure (SFS) interaction and extreme loading on structural behaviors are important issues in structural dynamics. System identification is an important technique to characterize linear and nonlinear dynamic structures. The identification methods are usually classified into the parametric and non-parametric approaches based on how to model dynamic systems. The objective of this study is to characterize the dynamic behaviors of two realistic civil engineering structures in SFS configuration and subjected to impact loading by comparing different parametric and non-parametric identification results. First, SFS building models were studied to investigate the effects of the foundation types on the structural …

Role Of Force Resultants Interaction On Fiber Reinforced Concrete, Titchenda Chan

Electronic Theses and Dissertations

Ultra-high performance concrete (UHPC) is a recently developed concrete gaining a lot of interest worldwide, and a lot research has been conducted to determine its material properties. UHPC is known for its very high strength and high durability. Association Francaise de Genie Civil (AFGC) has defined UHPC as a concrete exhibiting compressive strength greater than 150 MPa (22 ksi). To utilize the full compressive strength of UHPC, complementary tension reinforcement is required. A recent research study to find light weight yet high strength alternative deck systems for Florida movable bridges demonstrated that a composite UHPC and high strength steel (HSS) …

Characterization Of Impact Damage And Fiber Reinforced Polymer Repair Systems For Metallic Utility Poles, Cara Johnson

Electronic Theses and Dissertations

Previous studies have demonstrated that the behavior of fiber reinforced polymers (FRPs) bonded to metallic utility poles are governed by the following failure modes; yielding of the metallic substrate, FRP tensile rupture, FRP compressive buckling, and debonding of FRP from the substrate. Therefore, an in situ method can be devised for the repair of utility poles, light poles, and mast arms that returns the poles to their original service strength. This thesis investigates the effect of damage due to vehicular impact on metallic poles, and the effectiveness of externally-bonded FRP repair systems in restoring their capacity. Damage is simulated experimentally …