FE Analysis of Tucker High School Roof Using Nonlinear Geometry and Creep

Abstract

A nonlinear analysis that focused on geometric effects and also included the long-term effects of creep and shrinkage performed on the Tucker High School roof revealed an unstable shell with little capacity for increased loads. The hipped hyperbolic paraboloid roof collapsed under dead loads alone in 1970 after seven years of use. The nonlinear model included a realistic description of the geometry of the roof by using shell elements and solid elements instead of shell elements and beam elements. The finite-element analysis used the large rotation geometric nonlinearity and therefore accounted for the deformed geometry of the shell. The study, based on an uncracked material, also assumed that the incremental creep strains were proportional to the stresses and the incremental creep strain was exponentially decaying in time. The magnitudes of the creep strains after one year were close to the average for lightweight concrete based on the ACI guide.