PSI - Issue 62

Paolo Borlenghi et al. / Procedia Structural Integrity 62 (2024) 468–475 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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According to Tubaldi et al. 2018, the effects of scouring-induced settlements are related to pier-foundation rotations in the opposite direction of the river flow. In addition, the pier displacements start to increase beyond the values induced by vertical loads only after the maximum scour depth exceeds the foundation depth. In the present case, tiltmeters T03 and T07 (as well as other tiltmeters) experienced permanent rotations in the direction of the river flow; therefore, the phenomenon that caused the residual rotations should not be related to a soil settlement of the upstream side. It is worth mentioning that the distribution of vertical loads is not symmetric: the railway track – decommissioned in 2010 – is on the upstream side while the roadway is on the downstream side, causing an asymmetric distribution of service loads. In addition, the tiltmeters installed on the same pier began to exhibit the permanent rotations at different times so that those rotations are most likely induced by the arch. 6. Conclusions The paper presents the application of the RL guidelines for the structural/hydraulic risk-based assessment and monitoring on a historical Candia bridge. The paper moves from the preliminary documentary evaluation to the installation and deployment of a static monitoring system to control the effects of scouring on the structure. From the analysis of the monitoring data, the following conclusions can be drawn: (a) the tilt variations in the considered monitoring period for the selected sensors range from − 0.026° to +0.116°; (b) the outdoor temperature is confirmed as the dominant driver for the tilt variations; however, changes in the rotation-temperature correlation were detected during the monitoring period; (c) the physical phenomenon that caused the observed permanent shifts in the rotation-temperature correlation is still unclear and onsite visual inspections are periodically performed to detect the onset of possible cracks in the arches. Acknowledgements The support of Regione Lombardia is gratefully acknowledged. Sincere thanks are due to G. Cazzulani, PhD (DMECC, Politecnico di Milano), G. Zonno, PhD (DABC, Politecnico di Milano), M. Cucchi and M. Iscandri (LPMSC, Politecnico di Milano) who assisted the authors during the installation of the monitoring system. References Arena, M., Azzone, G., Urbano, V. M., Secchi, P., Torti, A., Vantini, S., 2022. Development of a functional priority index for assessing the impact of a bridge closure. In Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 1817-1822. Bianchi, S., Biondini, F., Rosati, G., Anghileri, M., Capacci, L., Cazzulani, G., Benedetti, L., 2022a. Structural Health Monitoring of Two Road Bridges in Como, Italy. Lecture Notes in Civil Engineering 200, 390 – 399. https://doi.org/10.1007/978 – 3 – 030 – 91877 – 4_45 Bianchi, S., Zani, G., Scalbi, A., Ferreira, K.F., D’Angelo, M., Anghileri, M., ..., Barassi, S., 2022 b. StradeNet: A regional road information system. In Bridge Safety, Maintenance, Management, Life – Cycle, Resilience and Sustainability, 1849 – 1856. Biondini, F., Ballio, F., di Prisco, M., Bianchi, S., D’Angelo, M., Zani, G., …, Ferreira, K.F. , 2022. Bridge vulnerability and hazard assessment for risk-based infrastructure management. In Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 1864-1873. Borlenghi, P., D’Angelo, M., Ballio, F., Gentile, C., 2022 a. Continuous monitoring of masonry arch bridges to evaluate the scour action. Lecture Notes in Civil Engineering 200, 400 – 408. https://doi.org/10.1007/978 – 3 – 030 – 91877 – 4_46 Borlenghi, P., Gentile, C., Zonno, G., 2022b. Monitoring Reinforced Concrete Arch Bridges with Operational Modal Analysis. Lecture Notes in Civil Engineering 200, 361 – 371. https://doi.org/10.1007/978 – 3 – 030 – 91877 – 4_42 D’angelo, M., Menghini, A., Borlenghi, P., Bernardini, L., Benedetti, L., Ballio, F., Belloli, M., Gentile, C., 2022. Hydraul ic Safety Evaluation and Dynamic Investigations of Baghetto Bridge in Italy. Infrastructures 7(4), 53. https://doi.org/10.3390/infrastructures7040053 Italian Ministry of Infrastructures CSLP, 2020. Guidelines on Risk Classification and Management, Safety Assessment and Monitoring of Existing Bridges. Rome, Italy. Limongelli, M.P., Gentile, C., Biondini, F., di Prisco, M., Ballio, F., Zonno, G., ..., Colombo, A., 2022. Bridge structural monitoring: the Lombardia regional guidelines. Structure and Infrastructure Engineering. https://doi.org/10.1080/15732479.2022.2107023 Martinengo, L., 1869. Ponte in muratura sul fiume Sesia nella ferrovia in costruzione di Asti – Casale – Mortara [Dissertation]. Regia Scuola d’Applicazione per gli Ingegneri di Torino. Tubaldi, E., Macorini, L., Izzuddin, B.A, 2018. Three – dimensional mesoscale modelling of multi – span masonry arch bridges subjected to scour. Engineering Structures 165, 486 – 500. https://doi.org/10.1016/j.engstruct.2018.03.031