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In this paper, an efficient methodology that could be implemented within any analysis software is developed to automate the design process of post-tensioned slabs. Optimization techniques are used to compute the necessary number of strands. The present methodology is based on computing an innovative influence matrix that contains the effect of each strand on stresses at a set of control points (points of peak stresses). This matrix will be used in the optimization avoiding reanalysis in each optimization iteration. The sum of the squares of the difference between the allowable stress and the computed stresses at all control points is considered an objective function. The optimization is then carried out under the constraints that the stresses at each control point should not exceed the allowable limit and to ensure that the number of strands is an integer value. Alternatively, the proposed methodology could be used as a value-engineering tool. Practical examples are presented to demonstrate the efficiency of the developed methodology. Highlights: • Automated design tool of practical PT slabs independent of designer experience. • Ability to perform value engineering tasks to obtain optimum number of cables in practical PT slabs. • Practical use of optimization methods in structural design automation tool. [ABSTRACT FROM AUTHOR]

In this paper, the domain integrals due to uniform load or self-weight that appear in the boundary element method (BEM) formulation for thick plates resting on elastic foundations are transformed to boundary integrals. The Reissner plate bending model is used to model the plate behavior, and the two-parameter Pasternak model is used to model the behavior of the foundation. The necessary particular solutions are derived, and the explict forms for the new boundary kernels are given. Two different collocation procedures are considered - external and boundary collocations. In the case of the boundary collocation and internal collocation (for computing internal functions) procedures, an additional free term is obtained, due to the discontinuity of the transformed kernels. The new boundary integrals are hypersingular integrals. However, it will be shown that these hypersingular terms vanish when integrated around a closed contour. Three numerical examples are presented with several parametric studies to demonstrate the accuracy of the present formulation.