PSI - Issue 78

Matteo Tatangelo et al. / Procedia Structural Integrity 78 (2026) 404–411 411 The target reliability indexes, ̅ ( , ) and ̅ 0 ( , ) , are shown using continuous and dashed red lines. For the estimated reliability index, Fig. 5 displays both the annual 1 ( ) and cumulative ( ) values, represented by dashed and continuous violet lines. The attention year, , and limit year, , are also marked with green and cyan dots, respectively. Fig. 5.a represents a scenario where is 100 years, and the actual trend of RC half-joint reliability over time is known, based on a specific corrosion law (8). Here, occurs at 78 th years, and the is at 95 th years. Consequently, under these conditions, and are determined to be 17 and 42 years, respectively. Similarly, Fig. 5.b presents the reliability analysis for =100 year, but in this instance, the past reliability history (i.e., the capacity trend) is unknown. Thus, as previously noted, a conservative assumption of constant capacity is employed; this simplification ultimately has minimal impact on the overall reliability assessment. Also, in Figure 5c, the past reliability history remains unknown, yet the assumption of = is applied (Fig. 1.c). It is observable that both and are reduced compared to the values found when =0 (Figs. 5.a and 5.b). This reduction occurs because, with = , the target reliability indexes, ̅ ( , ) and ̅ 0 ( , ) , are higher than when =0 . 5. Conclusions This study introduces a new reliability-based procedure for managing the life-cycle of both new and existing constructions. It transforms a time-integrated reliability assessment into a time-dependent one, thus offering a more in-depth assessment of structural integrity over the entire life of a construction. This approach adheres to current international standards that prioritize risk-informed design and cost-benefit evaluations. As for the RC half-joint, three scenarios were examined to illustrate how the procedure influences the reliability within the evaluation period. It is found that in all the scenarios considered if =0 is known, the assumption of constant past capacity does not significantly affect the resulting reliability index. Whereas, in the case of = the assessment is slightly more conservative. The introduced procedure is designed for life-cycle management, offering a unified approach for both new and existing constructions. This would enable a more adaptive management strategy, facilitating the timely identification of alert thresholds that progressively narrow the gap to the estimated time of limit state violation. References Freudenthal, A.M., Garrelts, J.M., Shinozuka, M., 1966. The analysis of structural safety, J. Structural Div., ASCE, 92 (ST1) 267 – 325 Holický, M., 2018. Target reliability of civil engineering structures. IOP Conf. Series: Materials Science and Engineering 365 052002. 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