DOMINI DI INTERAZIONE N-M E M-V NEI PONTI A CONCI COSTRUITI PER SBALZI SUCCESSIVI

Safety verification of prestressed concrete segmental bridges built by cantilevering are made in engineering practice through separate checks for axial force, shear force and bending moment. In this study a methodology for operating safety checks through interaction domains at serviceability and ultimate limit states is presented. Interaction between axial force and bending moment during construction stages and in the final configuration is considered as well as interaction between shear force and bending moment for failure conditions. A model based on the stress field theory is developed for plotting M-V domains. Moreover a case-study of a segmental bridge is presented, underlining the effects of internal force interaction and operating a comparison between internal and external prestressing, especially for failure conditions. Results show that separate verification could lead to unsafe evaluations, while interaction domains allow engineers to establish the actual safety conditions. The stress-paths during construction and service life are followed and design choices can be operated for prestressing and cross section properties of the bridge.