Engineering Commons^™

A Mechanics-Based Analytical Solution For Restrained Beams With Application To Progressive Collapse Behavior, Leven Deputy

Civil and Environmental Engineering Theses and Dissertations

This dissertation presents an axially restrained beam (ARB) model that incorporates axial-flexural interaction throughout the entire static load-deflection curve: the elastic material range, the plastic, flexural dominant range, the range beyond plastic flexure with increasing catenary effect, and the full catenary range. Energy methods are applied to static load-deflection curves to determine dynamic load-deflection relationships. Specifically, this dissertation considers the two conditions; Pinned-Pinned-Pinned (PPP) which has no flexural resistance at the boundaries, and Fixed-Fixed-Fixed FFF (also Pinned-Fixed-Pinned, PFP) condition which provides the beam with flexural resistance at the boundaries equal to flexural capacity of the beam. Behavior is explained analytically …

Component Testing And Characterization Of An Innovative Pressurized Sand Damper For The Response Modification Of Structures, Konstantinos Kalfas

Civil and Environmental Engineering Theses and Dissertations

This study is partly motivated by the need to develop sustainable energy dissipation devices that do not suffer from oil leakage due to failure of their end seals and from displacement limitations; and partly from the need to develop a robust damper that consists only of traditional civil engineering materials (sand and steel) in association with the use of post-tensioned steel rods with which practitioner civil engineers are familiar. Past failures of fluid dampers are both disruptive and costly, therefore not in-line with the current design paradigm of sustainable engineering, where the design and construction of structural systems shall meet …

Indirect Bridge Monitoring Using Crowdsourced Smartphone Data From Passing Vehicles, Jase Sitton

Civil and Environmental Engineering Theses and Dissertations

Bridges become susceptible to deterioration and damage as they age and are subjected to continually increasing demands. Bridge inspections help insure the integrity and safety for service and are conducted on a regular, but usually infrequency, basis. Traditional evaluation methods include visual inspections and permanent sensor installations. Visual inspections are both time and labor intensive and often require bridge closure or service interruption, while cost and logistics complications often prevent practical, widespread deployment of permanent sensor installations. Sensors, including smartphones, in moving vehicles may be used to monitor bridge condition over time and provide valuable insight into the dynamic behavior …

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 …

Truss Bridge Damage Localization And Severity Estimation Using Influence Lines, Hamoud Alshallaqi

Civil and Environmental Engineering Theses and Dissertations

The safety of bridges is one of the primary concerns of researchers, engineers, and bridge owners and managers, especially when bridges are approaching the end of their intended service lives. The estimation of bridge condition and remaining service life is critical to prioritize the allocation of available funding for repairs and rehabilitation. Various methods, including both dynamic and static approaches, have been developed to detect and localize bridge damage and estimate its severity. This research presents a methodology for detecting a single damaged member in a truss bridge and estimating the severity of the damage using static vertical deflection influence …

A Restrained Beam Sub-Model Assembly (Rbsa) For Progressive Collapse Analysis, Muath Alhumaidi

Civil and Environmental Engineering Theses and Dissertations

The progressive collapse failure mode occurs in buildings when a load-carrying element is lost due to extreme events such as explosions caused by terrorist attacks or vehicular impacts. Guidelines and many researches efforts have been established in order to limit and prevent total collapse of buildings after losing a load-carrying component (e.g., a column). Two famous examples of progressive collapse are the 1968 Ronan Point apartment building kitchen explosion on the 18^th floor and the 1995 Alfred P. Murrah Federal Building bombing in Oklahoma City. Both examples resulted in fatalities and injuries. A small number of these …

Response Modification And Seismic Protection Of Yielding Structures Equipped With Inerters And Hysteretic Dampers, Gholamreza Moghimi

Civil and Environmental Engineering Theses and Dissertations

This study investigates the seismic response of structures with sustainable, long-stroke response modification devices. The main thrust of the dissertation is the investigation of the seismic response of yielding structures equipped with supplemental rotational inertia, or inerters. The last chapter of this dissertation investigates the seismic response of multistory yielding steel structures equipped with pressurized sand dampers.

Inerters are mechanical devices with resisting force proportional to the relative acceleration of their end nodes. This class of response modification devices complements the traditional fluid viscous damping devices with resisting force proportional to the relative velocity at their end-nodes. Mass-amplification is the …

Context-Aware Sensing And Fusion For Structural Health Monitoring And Night Time Traffic Surveillance, Xinxiang Zhang

Electrical Engineering Theses and Dissertations

Rapid developments in computer vision technologies have been transforming many traditional fields in engineering and science in the last few decades, especially in terms of diagnosing problems from visual images. Leveraging computer vision technologies to inspect, monitor, assess infrastructure conditions, and analyze traffic dynamics, has gained significant increase in both effectiveness and efficiency, compared to the cost of traditional instrumentation arrays to monitor, and manually inspect civil infrastructures and traffic conditions. Therefore, to construct the next-generation intelligent civil and transportation infrastructures, this dissertation develops a comprehensive computer-vision based sensing and fusion framework for structural health monitoring and intelligent transportation systems. …

Behavior Of Geothermal Energy Piles Embedded In Rock, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Geothermal energy piles are categorized as closed systems. Energy piles are a relatively new technology which couples the structural role of traditional pile foundations to that of heat exchangers to fulfill the required energy demand of buildings and infrastructures. These foundations are equipped with pipes embedded in the concrete forming the pile. While connected to a heat pump, the fluid circulating inside these pipes provides the exchange of heat with the ground for heating and cooling purposes. As the undisturbed temperature at the shallower depths of the ground stays comparatively constant the whole year, being warmer than the surrounding temperature …

Flexural Rigidity Estimation Using Noisy Static Influence Lines, Yasha Hajizeinalibiouki

Civil and Environmental Engineering Theses and Dissertations

Society depends on critical infrastructure to support everyday activities. Even as critical components of civil infrastructure approach and exceed their design lives, demand on these structures continues to increase. In light of the need for managing aging infrastructure, several opportunities exist for research that can aid infrastructure managers in significant the challenge of detecting, classifying, and mitigating structural impairments. This dissertation presents a novel framework for impairment detection through the capture and utilization of deformation influence lines for flexural rigidity estimation on Euler-Bernoulli beams. In this research study, mechanical theory, a computer-vision algorithm, and multiple numerical methods are integrated to …