A novel segmental design for Condeep platforms

Construction of offshore concrete platforms involves considerable challenges due to the transportation and installation of heavy monolithic reinforced concrete structures. Modular or segmental construction offers a promising alternative by reducing construction time and cost while enabling deployment in deeper waters. This study proposes a novel segmental design and analysis approach for Condeep platforms through comparison with monolithic construction. Three-dimensional finite-element models were developed and validated against available experimental data to accurately capture load–displacement behaviour, crack width distribution, submerged natural frequencies, and corresponding mode shapes. The Draugen Condeep platform was analysed in monolithic and segmental configurations under service and ultimate limit states, considering relevant loading conditions. The results indicate greater ductility of the segmental platform than the monolithic design. Prestressing tendon stresses increased by ∼18%–30%, while the maximum crack width was significantly reduced from 3.21 to 0.34 mm, demonstrating improved stress redistribution and crack control. Moreover, the shear capacity of segmental joints was found to be comparable with, and in some cases up to 15% higher than, that of the corresponding cross-sections. Findings confirm that segmental modular construction can ensure reliable structural performance while improving flexibility, serviceability, and constructability of offshore concrete platforms under demanding marine conditions.