Engineering Commons^™

Reliability Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The reliability of reinforced concrete bridge columns strengthened with externally bonded, steel-fiber reinforced polymer fabric subjected to blast loads was investigated. Columns were modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. Different concrete strengths, longitudinal reinforcement ratios, and gravity and blast load levels were considered, while uncertainties in material strength and stiffness parameters, as well as load characteristics, were incorporated in the probabilistic analysis. It was found that the use of SFRP can allow significant increases in blast load while maintaining the same level of column reliability.

Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp

Graduate Theses and Dissertations

Lock gates are essential infrastructure components to the United State (US) supply chain. They create large cost savings and environmental benefits when compared with traditional methods of transport (freight and rail). Because of the large quantity of goods and dependence on these shipping chains, the US economy can be drastically affected by an unexpected gate closure. Unfortunately, many lock gates within the US have reached or exceeded their designed life. Due to the intensity of cyclic loads and the environment, fatigue cracks have become a prominent issue. Developed cracks near the pintle region (a joint which the gate rotates and …

Quantitative Resistance Assessment Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The blast resistance of a typical reinforced concrete bridge pier column design was modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. While varying concrete strength, amount of longitudinal reinforcing steel, and gravity load, the effect of applying an externally bonded steel fiber reinforced polymer (SFRP) wrapping was assessed. The presented approach uniquely quantifies column blast resistance in terms of charge weight. It was found that blast capacity was roughly linearly related to concrete strength and steel reinforcement ratio, the former of which is most influential. It was further found that a single layer of …

Long-Term Performance Evaluation Of Nudeck In Kearney East Bypass, George Morcous, Marc Maguire

Nebraska Department of Transportation: Research Reports

The Kearney East Bypass bridge is the first project that implements the newly developed precast concrete deck system (known as 2nd generation NUDECK). The new system consists of full-depth full-width precast prestressed concrete deck panels that are 12 ft (3.66 m) long each. The panels have covered shear pockets at 4 ft (1.22 m) spacing on each girder line to host clustered shear connectors that are adjustable in height. Narrow unreinforced transverse joints are used to eliminate the need for deck overlay. Also, deck panels are post-tensioned in the longitudinal direction using a new post-tensioning system that eliminates the need …

Performance Evaluation Of Inverted Tee (It) Bridge System, Garrett P. Martindale, Daniel Watson, Antony Mohsen Kamal Masoud Kodsy, Mostafa Abo El-Khier, Richard L. Wood, George Morcous

Nebraska Department of Transportation: Research Reports

The Inverted Tee (IT) girder bridge system was originally developed in 1996 by the University of Nebraska–Lincoln (UNL) researchers and Nebraska Department of Transportation (NDOT) engineers. This bridge system currently accounts for over 110 bridges in Nebraska used for both state highways and local county roads. Extensive longitudinal and transverse deck cracking have been observed and noted in numerous bridge inspection reports. Since the IT girder bridge system is relatively new, limited data and knowledge exist on its structural performance and behavior. This study evaluates the IT girder bridge system by conducting twenty field observations as well as recording accelerometer, …

Effect Of Subsurface Conditions On Flexible Pavement Behavior: Non-Destructive Testing And Mechanistic Analysis, Md. Fazle Rabbi

Boise State University Theses and Dissertations

The behavior of flexible pavements under traffic and environmental loading can be significantly affected by subsurface conditions. Inadequate support conditions under the surface can lead to excessive pavement deformations, often leading to structural and functional failure. This research effort focused on assessing the effects of base/subbase and subgrade layer conditions on flexible pavement behavior. The results of this study are presented in the form of two journal manuscripts.

The first manuscript focuses on utilizing pavement structural and functional evaluation data in making pavement rehabilitation decisions. Visual distress surveys and Falling Weight Deflectometer (FWD) testing are often carried out by agencies …

A 3d Numerical Analysis Of The Railway To Compare The Performance Of The Granular And Asphalt Trackbeds., Thammapot Wattanapanalai

Electronic Theses and Dissertations

In the last two decades, trains have been developed either to carry heavy weight of cargo or for high-speed rail transport. Nonetheless, track structure, have not been improved adequate to support the extra loads or dynamic vibrations of high-speed trains. As a result, the performance of track will be affected from heavy freight or high-speed trains. In the long term it results in trackbed damage by increasing the subgrade and ballast displacement. Besides, it negatively affects the performance of the locomotives. Therefore, alternative subballast, should be introduced to reduce the stress and deformation of the track under dynamic or heavy …

Structural Integrity Of Conventional And Modified Railroad Bearing Adapters For Onboard Monitoring, Joseph Montalvo, Alexis Trevino, Arturo A. Fuentes, Constantine Tarawneh

Mechanical Engineering Faculty Publications and Presentations

This paper presents a detailed study of the structural integrity of conventional and modified railroad bearing adapters for onboard monitoring applications. Freight railcars rely heavily on weigh bridges and stations to determine cargo load. As a consequence, most load measurements are limited to certain physical railroad locations. This limitation provided an opportunity for an optimized sensor that could potentially deliver significant insight on bearing condition monitoring as well as load information. Bearing adapter modifications (e.g. cut outs) were necessary to house the sensor and, thus, it is imperative to determine the reliability of the modified railroad bearing adapter, which will …

Evaluation And Analysis Of Highway Pavement Drainage, Kamyar C. Mahboub, Yinhui Liu, David L. Allen

Kentucky Transportation Center Research Report

This report presents an analysis of pavement drainage using various finite element models. The analysis included a range of pavement materials and drainage parameters. The computational tool in study was the SEEP/W option in the GEOSLOPE computer program. A steady-state saturated flow analysis was employed to generate flow paths and flux quantities through the cross-sectional area of the pavement. Finite element models in this study covered various drainage practices and quantified their relative drainage advantages. Finally, recommendations were provided for optimum drainage practices as well as future research topics in this area.

A 3-D Finite Element Structural Model Of An Instrumental Rigid Pavement (I-265 Gene Snyder Freeway, Louisville, Kentucky), Kamyar C. Mahboub, David L. Allen, Yinhui Liu

Kentucky Transportation Center Research Report

Field data that were generated from a section of concrete pavement on Gene Snyder Freeway (I-265), Louisville, Kentucky, were closely examined. An important conclusion of the field data examination was that the response produced by environmental load was more significant than traffic load and static load. To predict the mechanical behavior of the rigid pavement, a finite element model was developed for the project using the ANSYS program. The parametric study of the FEA model showed that the stiffness of subbase and subgrade had the most important effect on the mechanical response of the rigid pavement. On the basis of …