Issue 61

M.E. Kerkar et alii, Frattura ed Integrità Strutturale, 61 (2022) 530-544; DOI: 10.3221/IGF-ESIS.61.36

C ONCLUSION

T

he uncertainty can affect several parameters that are included in the calculation of the stability and dimensioning study, generally this study are based on a deterministic approach in which parameters take fixed values without taking into account uncertainty. In this work the objective is to estimate the reliability of some Algerian concrete gravity dams during the scenarios proposed in relation to the phenomenon of sliding, the uncertain parameters that have taken are; the friction angle ' φ ' and the cohesion 'C' and those are random variables in space or in time along the dam-foundation interface and in the body of the dike (concrete-concrete). Different load combinations have been proposed which are called failure scenarios ( C i ) that can encounter a dam during its service life as shown in Fig.1, the assumption is to accept the probability of a scenario C i equal to 1 ( P C i = 1), the calculation of the probability of failure by the three methods (First Order Reliability Method, Monte Carlo Simulations and Latin Hyper cube Sampling) has given us close and at times equal values and the idea is to take the most unfavorable value between these methods and consider it as the probability of failure to increase the safety margin. The exploitation of these results is an achievement in time to quantify the reliability of a dam by optimizing a maintenance and inspection policy, an example; On Friday August 07, 2020, the Beni Harroun dam site received seismic activities with a magnitude of 4.9 on the Richter scale according to the Astrophysical and Geophysical Astronomy Research Center (CRAAG), so if we accept that the operating rate for the drainage system is 90%, the P f at the time of the earthquake will be less than 3.51x10 -3 and 10 -7 respectively at the interface and at the heart of the dike, it is the inflection of the scenarios C 47 , C 48 according to Fig. 1 and if it will have a strong flood the probability of failure will be P f C19 =1.1x10 -3 and if there will be a failure in the drain valve or spillways gates during this flood P f C37 =1.18x10 -3 . In conclusion this study is a means of control for the safety of a dam knowing that the scenarios proposed can cover the events which encounter this type of structure during its service life. [1] Rasool, M. (2012). Dynamic and multi-perspective risk management of construction projects using tailor made Risk, Breakdow Structures. Doctorate, University of Bordeaux1, France, 02. [2] Azam, A., Mehdi, A. M., Seyed, A. H. M., Mohsen, R., Yong, L. (2020). Subset simulation method including fitness based seed selection for reliability analysis. Engineering with Computers, Springer. DOI: 10.1007/s00366-020-00961-9 [3] Reeve, D. (2010). Risk and Reliability. Coastal and Hydraulic Engineering, Spon Press 270 Madison Avenue, New York, NY 10016 USA, pp. 126-151. [4] Bomel (2001). Probabilistic methods: Uses and abuses in structural integrity. Executive health and safety, contract research report, UK, pp. 29-35 [5] Dalsgaard Sørensen, J. (2004). Structural Reliability Theory And Risk Analysis. Structural Reliability Theory And Risk Analysis. Institute of Building Technology and Structural Engineering, Denmark, 03. [6] International Committee Of Large Dams. (2005). Dam Foundations, Geologic considerations. Investigation methods, Treatment. Monitoring. Geologic considerations. Investigation methods of Treatment and Auscultation, Paris, ICOLD, 2005CD Rom. Bulletin, pp. 129-169. [7] Abdollahia, A., Amini, A., Hariri-Ardebili, M. A. (2022). An uncertainty-aware dynamic shape optimization framework: Gravity dam design. Science Direct, Reliability Engineering & System Safety journal, DOI: 10.1016/j.ress.2022.108402 [8] Droesbeke, J. J., Maumy-Bertrand, M., Saporta, G., Thomas-Agnan, C. (2014). Approaches statistiques du risque. Edition Technic 1 rue du Bac, 75007 Paris, France, 05 [9] Schneider, J. (2006). Introduction to Safety and Reliability of Structures. Structural Engineering Documents. 2 ed edition. Zurich, Suisse, 14. [10] Eddleston, M., Rose, C., Gallagher, E., Hope, I., Sugden, P. (2014). Quantitative risk assessment applied to sludge lagoon embankments. Maintaining the Safety of Our Dams and Reservoirs Proceedings of the 18th Biennial Conference of the British Dam Society. Queen's University of Belfast, 257, pp. 264-266. [11] Safe Work Australia. (2012). Guide for major hazard facilities safety case: Demonstrating the adequacy of safety R EFERENCES

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