Which capacity models for shear-critical reinforced concrete hollow piers?

The seismic assessment of existing bridges is nowadays a crucial aspect for resilient communities. Existing bridge piers are characterised by structural deficiencies often resulting in shear failures. Seismic assessment for shear-critical reinforced concrete hollow piers, widely used in bridges, is still an open issue. Currently, practitioners adopt formulations not validated for hollow piers notwithstanding their structural peculiarities. Herein, first, a review of existing shear capacity models from literature and codes is presented. Then, proper experimental data, related to both rectangular and circular hollow members, are collected and compared with the considered models to assess their reliability. Lastly, shear capacity models specific for the investigated structural typology are proposed. They showed very good agreement with the experimental data and can be simply used by practitioners for seismic assessment or design purposes