PSI - Issue 78

Abed Soleymani et al. / Procedia Structural Integrity 78 (2026) 815–822

821

Table 3. Results related to post-earthquake vertical load-carrying capacity and robustness indicator Accelerogram set A1 A2 A3 A4 A5 A6

A7

Post-earthquake vertical capacity [kN]

307,791 284,157 275,001 304,890 275,014 305,012 274,728

Robustness indicator [-]

0.976

0.901

0.872

0.966

0.872

0.967 0.871

Remaining traffic capacity (volume %)

100

75

50

100

50

100

50

According to the results presented in Table 3, the highest reduction in post-earthquake vertical load-carrying capacity was observed after applying seismic ground shaking corresponding to A7 accelerograms. On the other hand, applying seismic ground shaking corresponding to A1 accelerograms resulted in the lowest reduction in post earthquake vertical load-carrying capacity. Additionally, as shown in Table 3, except for the seismic loading scenarios consisting of A1, A4, and A6 accelerograms, the remaining traffic capacity under all other accelerogram sets (A2, A3, A5, and A7) cannot be considered equal to 100% in accordance with the criteria presented in Table 1. According to EC8 – 1 (EN1998-1, 2004), when seven accelerograms are used in seismic analysis, the average value of the response parameter (mean effect of the response parameter) can be considered instead of the maximum value of the response parameter obtained in structural analysis using three accelerograms. In this study, the average value of the robustness indicator was found to be 0.918, indicating a 90% remaining traffic capacity and performance level of immediate access after the earthquake in accordance with the criteria presented in Table 1. 7. Conclusions In this study, the post-earthquake traffic load-carrying capacity of a reinforced concrete deck-stiffened arch bridge damaged by earthquake is investigated. The results of seismic analysis revealed that the failure mechanisms of structural elements were restricted to shear failure of deck beams and arch elements. The robustness indicator was assumed as the ratio between residual (i.e., post-earthquake) and initial (i.e., pre-earthquake) load-bearing capacity of the bridge against traffic loads. According to pushdown analysis results, the robustness indicator ranged from 0.871 (minimum) to 0.976 (maximum), representing remaining traffic capacities of 50% and 100%, respectively. Moreover, considering the mean effects of the response parameter, the mean values of robustness indicators and remaining traffic capacity were 0.917 and 90%, respectively. Future developments of this study might include the robustness assessment using alternative indicators, as well as ageing and deterioration phenomena, and other extreme load scenarios capable of inducing local damage to the structure. Acknowledgements This study was developed within the following projects: FIRMITAS (Grant No. 2020P5572N) funded by the Italian Ministry of University and Research; FAIL-SAFE (Grant No. P2022X7N2S_002) funded by European Union through Next-GenerationEU programme – National Recovery and Resilience Plan (PNRR) – Mission 4, Component 2, Investment 1.1, PRIN 2022 programme of the Italian Ministry of University and Research (D.D. 854 02/02/2022, n.104). References Berry, M.P., Eberhard, M.O., 2003. Performance models for flexural damage in reinforced concrete columns. Pacific Earthquake Engineering Research Center, Berkeley, California, PEER Report 2003/18. Computers and Structures, Inc. (CSI), 2022. SAP2000. Version 24.2. Berkeley, California. Dhir, P.K., Losanno, D., Tubaldi, E., Parisi, F., 2025. Performance and robustness assessment of roadway masonry arch bridges to scour-induced damage using multiple traffic load models. Engineering Structures 325, 119441. De Biagi, V., Parisi, F., Asprone, D., Chiaia, B., Manfredi, G., 2017. Collapse resistance assessment through the implementation of progressive damage in finite element codes. Engineering Structures 136, 523 – 534. EN1991-2, 2003. Eurocode 1: Actions on structures ― Part 2: Traffic loads on bridges. European Committee for Standardization, Brussels, Belgium.