RELIABILITY OF REINFORCED-CONCRETE CYLINDRICAL-SHELLS

Reinforced concrete shells are structurally complex and closed-form models for their various limit states of serviceability and strength either are not available or may be based on approximations and idealizations of behavior. Nonlinear finite-element techniques have made it possible to account for account for the complexities of reinforced concrete behavior in the inelastic range, to identify these limit states more accurately, and to assess the safety and reliability of concrete shells. Traditional reliability analysis methods are more convenient to apply when closed-form mechanical models of limit states are available. In the absence of such models, the reliability analysis can be performed by response surface methods that approximate the limit states by polynomial surfaces obtained through finite-element analyses of the system at a set of predetermined experimental points. This paper presents the reliability analysis of a reinforced concrete containment structure by the response surface method. Axisymmetric nonlinear finite-element analyses were performed to define the limit surfaces and importance sampling was used for the calculation of limit state probabilities.