Date of Graduation

8-2024

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Murray, Cameron

Committee Member

Prinz, Gary

Second Committee Member

Fernstrom, Eric

Keywords

Temporary bridge; Superstructures; Rapid deployment

Abstract

Rapidly deployable temporary bridges are critical for military operations in hostile environments. The research focuses on conceptualizing bridge solutions for MLC 40 loading and 30 feet span that can be operational within hours, require minimal personnel and equipment, and are compact for logistics. An extensive literature review covered historic deployable structures, retractable stadium roofs, structures in aerospace, permanent deployable bridges, current military bridges, innovative deck solutions, lightweight structural materials, and compliant mechanisms. The study then investigated bridge superstructures made of lightweight Aluminum 6061-T6 alloy utilizing tensegrity and prefabricated aluminum extruded decks to meet the criteria. Two concepts, expandable scissor truss and collapsible tube girder bridge both utilizing trackway systems were outlined. Preliminary sizing for the members was performed as per Trilateral Design and Test Code, Aluminum Design Manual 2015 and manufacturers’ catalogs. The collapsible tube girder bridge was considered the more viable option and using these preliminary sizings, a Finite Element Analysis (FEA) using ABAQUS was performed. Shell elements were used for girder and stiffeners to evaluate local stresses and any concentrated material yielding, while wire elements were used to simulate kickers and lower tension cable. Results from FEA showed that none of the elements yielded and vertical deflections were within tolerances. A 1/3 rd scaled model to explore only deployability and not the evaluation of engineering properties was built using materials that were easy to obtain and fabricate.

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