Numerical Simulation & Push-off Test Validation of Full-Depth Precast Bridge Decks with Large Stud Clusters in UHPC Shear Pockets

Full-Depth Precast Concrete (FDPC) bridge deck panels are increasingly used in highway construction due to their rapid installation, ease of replacement, and cost-effectiveness. To improve composite action, clusters of large headed-stud connectors embedded in Ultra-High-Performance Concrete (UHPC) shear pockets have been introduced, however, this configuration often induces high stress concentrations and premature cracking around the pockets. This study develops and validates a finite element (FE) model of FDPC panels incorporating L-angle confined UHPC pockets with clustered large studs, based on push-off tests under eccentric loading. The FE simulations accurately reproduced experimental behavior, with predicted ultimate loads and crack patterns closely matching test results for specimens with a cluster of 4, 6, and 8 studs. Parametric analyses showed that finer mesh sizes (10–30 mm) improved crack localization but underestimated ultimate loads (up to 8.3%). Push-off stiffness was influenced by LVDT placement (with 10–20%) due to localized slip and by eccentric loading positions, which significantly affected shear capacity and premature crack pattern. L-angle confinement enhanced shear resistance by up to 15%. Comparisons with experimental data and American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) bridge design equations confirmed that the FE model provides a reliable and efficient analytical tool for optimizing FDPC bridge deck connections with large stud clusters and UHPC shear pockets.