OpenSEES Procedures for Implementing Reliability Analysis of RC Frames

Seismic reliability analysis is one of the most advanced tools for assessing the actual levels of safety of structures, duly taking into account both the mechanical behaviour of reinforced concrete (RC) members and the key features of the seismic actions. The methods currently available for evaluating seismic reliability requires executing a significant number of Non Linear Time History (NLTH) analyses according to the Incremental Dynamic Analysis (IDA) procedure. As a matter of fact, reducing the computational effort needed by the aforementioned methods and transferring their use to common practitioners are the two main challenges in disseminating to civil engineers the most recent advances in knowledge on seismic reliability. In this regards, the Italian National Council of Research (CNR) have recently given a significant contribution by releasing the Technical Document 212 (DT 212, in the following), a guideline for the seismic reliability assessment of existing structures. This paper describes some procedures intended as the kernel of a possible OpenSEES add-on, capable of providing practitioners with a computationally efficient operational tool for performing reliability analysis of real existing RC frames. After having outlined the main contents of DT 212, the paper describes the conceptual formulation of the procedures and highlights some details of their mplementation in a high-level programming language. A sample application of the proposed procedures is also proposed by considering a RC frame originally designed for gravitational loads only