Research on Crack Control Method of Girder End Anchorage Zone Based on Nonlinear Finite Element Analysis

A new, contemporary post-tensioned prestressed concrete I girder is created for a hydropower facility to accommodate larger loads in services. The increased transverse tensile loads caused by the enhanced I-girders with more tendons, however, have raised the possibility of girder end cracking. In this study, solutions for controlling cracks on the targeted girders were investigated. A modified finite element analysis model was used to simulate girder end behaviors and investigate effective crack management approaches. Two solutions were investigated: altering the girder's anchoring end section and enhancing the reinforcement. The findings indicated that the girder end cracks, which included horizontal cracks under the anchorage plate and inclined cracks at the upper corner of the anchoring plate, followed predictable patterns. Excessive tensile stresses generated by the various tendon tensioning sequences, as well as excessive initial tensioning control stresses, all contributed to the cracks that formed during the prestress tensioning procedure. The first method could not fundamentally eliminate the appearance of cracks, while the second method modifying the reinforcement could control the appearance of cracks.