Engineering Commons^™

Evaluating The Impact Of Bridge Deck Removal Method On The Performance Of Precast/Prestressed Concrete I-Girders, Shaddi Assad

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Wide flange precast/prestressed concrete I-girders have been widely used by several State Departments of Transportation (DOTs) in the last two decades. These girders have many advantages over standard AASHTO I-girders. Their wide and thick bottom flange accommodates a large number of prestressing strands and their wide and thin top flange provides a shorter deck span, reduced girder weight, greater stability in construction, and adequate platform for workers. Despite these advantages, the wide and thin top flange might be disadvantageous when it comes to deck removal, as it is more susceptible to damage. Therefore there is a need to investigate the …

Increased Span Length For The Mgs Long-Span Guardrail System, Nicholas A. Weiland

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Long-span guardrail systems have been recognized as an effective means of shielding low-fill culverts while minimizing construction efforts and limiting culvert damage and repair. The current MGS long-span design provided the capability to span unsupported lengths up to 25 ft (7.6 m) without the use of nested guardrail. The excellent performance of the MGS long-span system in full-scale crash tests suggested that longer span lengths may be possible with the current design.

A detailed analysis of the MGS long-span guardrail system was performed using the finite element software program LS-DYNA^®. It was shown that the MGS long-span design …

Development Of A Mash Tl-3 Transition Between Guardrail And Portable Concrete Barriers, David A. Gutierrez

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Often, road construction causes the need to create a work zone. In these scenarios, portable concrete barriers (PCBs) are typically installed to shield workers and equipment from errant vehicles as well as prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed in order to place the portable concrete barrier system. The focus of this research study was to develop a proper stiffness transition between W-beam guardrail and portable concrete barrier systems. This research effort was accomplished through development and refinement of design …

Equipment Fragility Due To Shock Response, Christopher Y. Tuan

Department of Civil and Environmental Engineering: Faculty Publications

Because of its simplicity, the shock response spectrum has become widely used as a means of describing the shock responses and fragilities of structures and equipment. This paper focuses on the drawbacks of using the shock response spectrum for defining equipment shock tolerance. A cantilever beam with a tip mass was used to model a hypothetical piece of equipment subjected to strong ground motion such as that caused by an explosion. The exact solution from a detailed modal analysis shows that multiple modes of response were excited. Contributions from higher modes can be more predominant than that from the fundamental …