Comparison of the overlapping lattice and thefinite element approaches for the prediction of the collapse state of concrete gravity dams

Soysal, Berat Feyza
Arıcı, Yalın
Binici, Barış
Tuncay, Kağan
Estimating the collapse limit state of concrete gravity dams within the framework of performance based design is challenging due to the uncertainty in modelling the response of these systems and the strong dependence of the behavior on the ground motion. In this context, the purpose of the study is to investigate the prediction capability of numerical tools in determining the collapse state of concrete gravity dams. The first tool used to this end is the classical finite element method with the smeared cracking approach. The second is the overlapping lattice model (OLM) employing pin connected bar elements extending over a predefined horizon to discretize the continuum similar to the concept used in peridynamics. Particularly suited to simulating the discrete cracking occurring in plain concrete structures, OLM has the potential to avoid the classical problems in predicting cracking on FE analyses such as the extensive spreading of the damage region. The comparison of the analysis tools were conducted using incremental dynamic analyses (IDA) for two representative dam monoliths. The results from the FE analyses and the OLM approach were markedly different, with the former displaying smeared damage on a considerable area of the dam body while in the latter, discrete, localized cracking going through the whole body was observed for the strong shaking scenarios. In contrast to the FE, the OLM approach was able to simulate the separation of the dam body through a number of discrete cracks forming from the U/S to D/S side.