Impact behavior of reinforced concrete slabs subjected to rock fall loading

Abstract

This research aims at providing a better understanding of the dynamic behavior of rock fall protection galleries. To improve the prediction accuracy for the impact load capacity, analytical, numerical and experimental works have been carried out. According to a survey of galleries in Switzerland, the relevant geometries for the tests were chosen in a scale of about 1:2. Concrete slabs with lateral dimensions of 3.5 x 4.5 m and a thickness of 0.35 m were subjected to falling weight impacts with increasing falling height. Measuring the reaction forces as well as strains in the reinforcement and on the concrete surface, the required data to validate an analytical model was gained. In this contribution, the observed crack patterns of the slabs due to the impacts are discussed. The impact load and the strains can be predicted using an analytical model consisting of three masses and three nonlinear springs. As a comparison, the values given by the design guidelines of Switzerland and Japan are illustrated, too.