Long term axial shortening in a tall concrete structure is a second-order effect that is ofudsome impediment to the serviceability, and in some cases, structural integrity of theudbuilding. The research here involves analysis of axial shortening elements that interactudthrough framing action. In many tall concrete buildings framing is inherent as columns,udbeams and floors are quite often connected with rigid connections. The mechanics ofuddifferential axial shortening and framing action due to rigid connections causes loadudsharing between vertical elements that fundamentally affects the degree of both absoluteudand differential axial shortening. Evaluation of axial shortening by analysis of audstructural system consisting of discrete elements over-predicts the level of axialudshortening when framing is present. udA methodology to calculate axial shortening, accounting for load sharing of axial loadsudfor tall concrete buildings, is developed. The application of this methodology to theudconstruction of a tall concrete building allowing for the building cycle is presented. Audprogram is written that incorporates both the methodology and its application to a talludbuilding, using the ACT concrete creep and shrinkage models. Correlation of theudprogram is made against an existing previously tested program that does not allow forudframing action. A comparison is made between the two sets of data for an actual 85udstorey building. From this it is concluded that; udi) Framing action reduces the differential axial shortening between two elements udii) The core generally experiences less change to axial shortening than columns udiii) The effect of framing cannot be estimated by a relative percentage adjustmentudapplied uniformly to each storey.
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