Structural reliability of reinforced concrete hydraulic structures - A case study

Hydraulic structures differ from buildings and bridges by the types of loads, their spatial distribution and the load combinations. This contribution investigates the verification of the reliability of hydraulic structures by means of different reliability methods. These include the semi probabilistic method, which employs partial safety factors, and two selected fully probabilistic methods, the first order reliability method (FORM) and subset simulation. The reliability analysis framework was implemented for a half frame reinforced concrete ship lock structure. The mechanical models applied for the structural reliability analysis follow those of Eurocode. Eight limit state functions were assessed, by consideration of different sections (wall and base slab), design situations (persistent and transient) and failure criteria (bending moments with normal forces and shear forces). The sections designed through partial safety factors and analysed by full probabilistic methods indicate slightly higher reliability indexes than target reliability indexes. The results of FORM analysis were verified by subset simulation which showed comparable results for all investigated limit states. The sensitivity analysis indicated water levels in chamber, coefficient of earth pressure and resistance model uncertainties as most critical parameters.