UNCERTAINTY QUANTIFICATION OF FRACTURE POTENTIAL AT CONCRETE-ROCK INTERFACE FOR GRAVITY DAMS

Resumo

The uncertainties are present in engineering projects, in which can be due to materials,
models or constructive inaccuracies. This is very important in dams, because the failure of this
structure can lead to enormous social, economic and environmental impacts. In addition, dams must
resist overtopping occurrence, in which it has intensity, period and duration variabilities. Thus, this
paper aims to analyze the behavior of a concrete gravity dam in the presence of a crack along interface
dam/foundation, where it is, normally, the weakest zone of the structure. The study of this
discontinuity was based in linear elastic fracture mechanics, considering mixed-mode propagation, due
to the particulars of the problem. Furthermore, a reliability analysis was made to take account the
uncertainty of main design properties and loadings. The results showed the tendency of energy release
rate to follow a lognormal distribution. The importance of flood control was evidenced, because the
analyzed dam presented high failure probability with overtopping. Moreover, consider triangular uplift
or constant uplift acting on the crack generated great differences in reliability analysis.