Une approche progressive pour l'évaluation de la stabilité sismique 3D des piliers d'évacuateurs de crues

During the last decades, seismic standards for hydraulic structures have become more demanding. Many aging hydraulic structures are subject to seismic stability reassessment studies to ensure their safety. In the absence of a precise methodology, dam safety engineers must make choices of approach for a rapid assessment of the seismic stability of spillways without resorting to complex and time-consuming finite element models. Most of the existing simplified methods consider only a seismic excitation in the upstream-downstream direction. However, spillway pillars can be particularly affected by seismic excitations in the direction of the banks which corresponds to the weak axis of bending because of a lower moment of inertia. This report presents a progressive calculation approach using a simplified model of beam-column elements (stick model SAP2000) considering a three-dimensional seismic excitation. The objective is to evaluate the stability of pillars at critical sections using the forces obtained with the simplified stick model. First, the use of sectional analysis software Sectionproperties and Cross Section was validated by comparing the results (sectional mechanical properties, stress distribution, location of the neutral axis, cracking) to reference responses for different geometries of unreinforced and reinforced sections.