Date of Award
Civil and Environmental Engineering
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In this dissertation the author investigates the behaviour of reinforced and prestressed concrete waffle slabs from initial to collapse load. The theoretical treatment covering the whole range of load, is divided into three parts: elastic analysis, ultimate analysis, and progressive failure analysis. The elastic analysis part is based on a Fourier series solution for simply supported slabs and this is extended to continuous waffle slab structures. The ultimate limit state analysis is obtained by adopting the yield line theory as an upper bound solution. The progressive failure analysis is tackled by the finite element method as a numerical technique; beyond the initiation of the first crack at sections of maximum stresses, an iterative incremental procedure is adopted to take into account the reduction of rigidities with the corresponding increment of loading, thus converting the non-linear problem into a series of incrementally linear problems in the elastic-plastic range. Comparison of results is made between skew and rectangular waffle slabs as well as between continuous slabs on isolated supports and on continuous line-supports. A study of the effect of rotating the isolated column support line about the center of the bridge on the structural response is undertaken. The theoretical analyses are substantiated and verified by experimental results obtained from tests on seven models of reinforced and prestressed concrete waffle slab bridges. The deflections and strains obtained from the tests are found to be in good agreement with the theoretical solutions. From this study it is concluded that the yield-line analysis is simple and reliable in predicting the ultimate load of waffle slab structures. Furthermore, prestressed concrete waffle slab construction is well suited for use in large span structures. Also, in predicting the collapse load of waffle slab structures, it is found that the progressive failure analysis of such structures gives results which are in close agreement with those obtained from the tests as well as from the yield-line analysis.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1982 .S422. Source: Dissertation Abstracts International, Volume: 43-07, Section: B, page: 2279. Thesis (Ph.D.)--University of Windsor (Canada), 1982.
EL-SEBAKHY, IBRAHIM SAYED AHMED., "ELASTIC AND ULTIMATE BEHAVIOUR OF WAFFLE SLAB STRUCTURES." (1982). Electronic Theses and Dissertations. 1887.