Calibration of shear strength calculation models to bridge slabs with emphasis on the national designs practice

Abstract

The shear force strength has attracted, over the last decades, great discussions about the understanding of the involved mechanisms and their quantification. A large number of mechanical models developed mostly deal with the shear strength of beams or the concentric punching of slabs. However, in the case of loads distributed in small areas close to the support, a usual situation in bridge deck slabs, not all the width of the supports is mobilized. For this reason, it is generally necessary to define a cooperative/effective width in the shear strength. In this aspect, many works were developed evaluating the level of precision of different calculation models combined with different ways of defining the effective width. However, most of these were performed with slabs of thicknesses greater than those practiced in Brazilian designs and using a deterministic approach in the calibration of calculation models. For this reason, the aim of this research proposal is to develop a most suitable study about the national practice of designs regarding the use of thinner slabs (200-250 mm). In addition, it is proposed the use of probabilistic tools combined with a more comprehensive database for the development of more accurate calculation models for this type of request. In this way, it is intended to develop an experimental program, in addition to the database of experimental results built in the master course of the candidate, including parameters little or not evaluated in the most recent publications that allow a better understanding of the physical mechanisms of the problem. The study also includes numerical simulation of experimental results and parametric analysis of the calibrated models, using the finite element method, to investigate in a more detailed way the influence of aspects as the arching effect and the arrangement of corbels in slabs requested by loads distributed in small areas close to the support. (AU)