Structural Performance Assessment of Post-Tensioned PC-U Girders for 25 m and 50 m Industrial Bridge Spans

Abstract

A 380 m industrial bridge connects the JIIPE Industrial Estate to Pulau Segitiga in Gresik, Indonesia. This study evaluates the structural performance of post-tensioned prestressed-concrete U (PC-U) girders for representative 25 m side spans and a 50 m main span using section calculations and three-dimensional SAP2000 analysis. The assessment covers prestressing demand, immediate and time-dependent losses, anchorage-induced principal tensile stress, live-load deflection, and preliminary erection feasibility. Required prestressing forces are 9,278.7 kN and 25,348.7 kN for the 25 m and 50 m girders, respectively. Total prestress losses are 26.1% and 27.6%, below the adopted 28% planning estimate. Maximum principal tensile stresses after anchorage are 2.519 MPa and 2.676 MPa, below allowable values of 2.556 MPa and 2.761 MPa. Live-load deflections are 17.10 mm and 60.35 mm, satisfying the corresponding L/800 limits of 31.25 mm and 62.50 mm. P Preliminary lifting checks indicate that the assumed half-girder lifting configurations are feasible within the adopted crane-chart capacities. Both girder configurations satisfy the structural criteria evaluated in this study under the stated assumptions; however, the 50 m girder governs the serviceability and lifting requirements, utilizing 96.6% of the allowable deflection and approximately 90% of the adopted crane-chart capacity. The lifting assessment represents only a preliminary erection-feasibility screening and does not constitute a final lifting or erection plan. Detailed anchorage-zone design, camber verification, construction-stage analysis, temporary stability assessment, field verification, and project-specific erection planning are therefore required before implementation.