Structural Engineering Commons^™

Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh

All Dissertations

The Federal Highway Administration (FHWA) recognizes the necessity for cost-effective and practical system identification (SI) techniques within structural health monitoring (SHM) frameworks for asset management applications. Indirect health monitoring (IHM), a promising SHM approach, utilizes accelerometer-equipped vehicles to measure bridge modal properties (e.g., natural frequencies, damping ratios, mode shapes) through bridge vibration data to assess the bridge's condition. However, engineers and researchers often encounter noise from road roughness, environmental factors, and vehicular components in collected vehicle signals. This noise contaminates the vehicle signal with spurious modes corresponding to stochastic frequencies, impacting damage monitoring assessments. Thus, an efficient and reliable SI …

Estimation And Mitigation Of Stresses In Mass Concrete Structures Containing Ground Granulated Blast Furnaceslag And Fly Ash, Guadalupe Leon

Graduate Theses, Dissertations, and Problem Reports

In large concrete structures, due to concrete’s low thermal conductivity, the interior temperature rise can approach the concrete’s adiabatic temperature rise. As the concrete’s surface losses heat to the environment and cools rapidly, the interior of the concrete attempts to expand while the exterior provides an internal restraint. The phenomenon causes thermal stresses at the concrete’s surface. If the thermal stresses exceed the concrete’s tensile strength, there is a high probability of cracking. The cracks usually appear during the first few days after construction while the concrete’s tensile strength is low. These early-age cracks can reduce the service life of …

Computational Modeling Of Laminated Veneer Bamboo (Lvb) Dowel Joints, Niloufar Khoshbakht

Doctoral Dissertations

Laminated veneer bamboo (LVB) is a sustainable building material that has been gaining interest in the construction industry of late. As a relatively new product, little is known about its connection performance, specifically, its failure behavior in dowel type joints and possible similarities it may have to engineered wood products in terms of failure mechanisms. Research is needed to aid in the understanding of LVB dowel connection failure behavior and to quantify the failure mechanism and key factors associated with LVB dowel connection strength. Modeling, as conducted in this research, is a valuable tool to help devise safe standards and …

Strength Structure Analysis Of Main Gate Graving Dock Using Pontoons For Condition Repairs, Budianto Budianto

Makara Journal of Technology

Main gate graving dock with pontoon type can certainly suffered some level of damage after a long period of operation. Many employments within the graving dock can delay the process repair of main gate. The main gate may not be opened, because employees are still working to ship fabrication process under sea waterline. For accommodate these interrelated conditions, the best solution with repair one side of the main gate with type pontoon and employees can still work ship fabrication process in graving dock conducted simultaneously. The repair process conditions must be required main gate structure that consists of only one …

Seismic Performance Of Steel Helical Piles, Moustafa K. El-Sawy

Electronic Thesis and Dissertation Repository

Recent earthquakes have highlighted the need for safe and efficient construction of earthquake resilient structures. Meanwhile, helical piles are gaining popularity as a foundation for new structures and retrofitting solution for existing deficient foundations due to their immense advantages over conventional driven pile alternatives. In addition, helical pile foundations performed well in recent earthquakes, proving they can be a suitable foundation option in seismic regions. The objective of this thesis is to evaluate the seismic performance of helical piles by conducting full-scale shaking table tests and nonlinear three-dimensional numerical modeling using the computer program ABAQUS/Standard. The experimental setup involved installing …

A Comparison Of Force And Pressure Coefficients On Dome, Cube And Prism Shaped Buildings Due To Straight And Tornadic Wind Using Three Dimensional Computational Fluids Dynamics, Majdi A. A. Yousef

Graduate Theses and Dissertations

Tornadoes induce very different wind forces than a straight-line (SL) wind. A suitably designed building for a SL wind may fail when exposed to a tornado-wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Most studies have been conducted to investigate tornado forces on cubic, gable-roof and cylinder buildings. However, little attention has been paid to investigate tornado force on dome buildings; hence, further research is conducted in this study. The forces on a dome, cube and prisms were analyzed and compared using Computational Fluid Dynamics (CFD) for tornadic and SL …

Analysis And Design Procedure For Liquid-Filled Conical Tanks Under Seismic Loading, Ahmed Musa

Electronic Thesis and Dissertation Repository

Steel conical tanks are widely used for liquid storage in North America and elsewhere. A number of those tanks collapsed in the last decades as a result of instability of the steel shells. Despite being widely used, no specific design procedure is available for conical tanks under dynamic conditions. The research conducted in the current thesis presents a simplified approach for the design of steel conical tanks when subjected to ground excitations in the form of horizontal and vertical excitations.

First, the capacity of steel conical tanks to avoid yielding and buckling of the tank vessel under hydrodynamic pressure resulting …

Behaviour Of Reinforced Concrete And Composite Conical Tanks Under Hydrostatic And Seismic Loadings, Ahmed Elansary

Electronic Thesis and Dissertation Repository

Conical liquid storage tanks are widely used to store different liquids and to provide water supply at cities and municipalities. However, no comprehensive guidelines currently exist in the codes of practice for the structural analysis and design of such tanks. The walls of a conical tank can be made of steel, reinforced concrete, or a combination of the two materials in a composite type of construction in which steel and concrete walls are connected using steel studs. The research conducted in this thesis provides a comprehensive understanding of the structural behaviour of reinforced concrete and composite conical tanks under hydrostatic …

Circular Rc Columns Partially Confined With Frp, Sahar Y. Ghanem

Theses and Dissertations--Civil Engineering

Wrapping reinforced concrete (RC) columns with Fiber Reinforced Polymer (FRP) composites is effective in increasing their capacity. The current state of art concentrates primarily on fully wrapped RC columns and few studies dealt with partially wrapped columns. The majority of the studies did not account for the influence of the existing steel reinforcement on the column’s behavior. Other studies estimated the total confinement pressure as the sum of the confinement pressure due to the external FRP jacketing and due to the internal transverse steel reinforcement. Few models dealt with the coupled effect of the confinement from steel and partial FRP …

Numerical And Experimental Studies Of Transmission Lines Subjected To Tornadoes, Ahmed Hamada

Electronic Thesis and Dissertation Repository

The majority of worldwide weather-related transmission line failures have been attributed to High Intensity Wind (HIW) events in the form of tornadoes and downbursts. The research conducted in the current thesis presents a significant development in the understanding of the structural behaviour of transmission line systems under tornado loading. A comprehensive in-house numerical model that combines the data of computational fluid dynamic (CFD) simulations of tornado wind fields with three dimensional nonlinear structural analysis modelling is developed. A three dimensional four-nodded cable element is first formulated to simulate the nonlinear large deformation behaviour of the conductors. The support provided to …

Performance Of Circular Reinforced Concrete Bridge Piers Subjected To Vehicular Collisions, Nevin L. Gomez

Masters Theses

Vehicle collisions with bridge piers can result in significant damage to the support pier and potentially lead to catastrophic failure of the whole structure. The Nation’s aging infrastructure suggests that many structures no longer meet current design standards, placing many bridge susceptible to failure if subjected to an extreme loading event. This research aims to study the structural response of reinforced concrete bridge piers subjected to vehicle collisions. A sensitivity analysis is conducted to observe the causes of shear and bending failures of bridge piers subjected to vehicle collision. Parameters, such as pier diameter, transverse reinforcement spacing, vehicle impact velocity, …

The Response Of A Footbridge To Pedestrians Carrying Additional Mass, Darragh O'Sullivan, Colin Caprani, Joe Keogh

Conference papers

Footbridges with low natural frequency are susceptible to excessive vibration serviceability problems if the pedestrian pacing frequency matches the bridge natural frequency. Much research has been done into describing the response of a footbridge to single pedestrian loading. However, many pedestrians carry additional mass such as shopping bags and backpacks, and this has generally not been accounted for in previous research. This work examines this problem using an experimental bridge excited with many single pedestrian events, both with and without additional mass. The vertical acceleration response is measured and compared to moving force, moving mass, and moving spring-mass-damper models. The …

Experimental And Numerical Development Of Anchor-Jointed Precast Structural Wall System And Optimum Design Of Prestressed Slabs, Mohamed El Semelawy

Electronic Thesis and Dissertation Repository

Precast concrete shear walls are used to resist lateral loads in low- to medium-rise buildings. An innovative joining technique is proposed to accelerate construction process and to reduce concrete damage possibility and capital loss during an earthquake event. Panels are jointed using steel anchor bolts, therefore, the system is designated "anchor-jointed precast structural wall system". In this system, anchors are utilized as a structural fuse. Damaged anchors are easily replaced after an earthquake, thus minimizing repair costs and serviceability disruptions. In the first part of this thesis, conceptual development of the system is carried out. A research program of combined …