Issue 43

A. Luciani et alii, Frattura ed Integrità Strutturale, 43 (2018) 241-250; DOI: 10.3221/IGF-ESIS.43.19 241 Maintenance and risk management of rockfall protection net fences through numerical study of damage influence Andrea Luciani, Carmine Todaro, Daniele Peila Politecnico di Torino, Torino, Italy andrea.luciani@polito.it , carmine.todaro@polito.it , daniele.peila@polito.it A BSTRACT . Rockfall protection net fences are key protection systems in mountainous areas worldwide to ensure the safety of infrastructures, roads and urban areas. Maintenance of these products is fundamental for public administrations in order to guarantee risk mitigation. This paper deals with the assessment of the installation problems and damages induced by ageing of rockfall protection net fences, using numerical modelling in order to evaluate the influence of these issues on their behavior. A percentage of the residual efficiency is assessed as a useful tool for risk analysis and maintenance planning. K EYWORDS . Rockfall protection net fence; Rockfall; Explicit numerical modelling; Residual risk; Maintenance. Citation: Luciani, A., Todaro, C., Peila, D., Maintenance and risk management of rockfall protection net fences through numerical study of damage influence, Frattura ed Integrità Strutturale, 43 (2018) 241-250. Received: 23.10.2017 Accepted: 15.12.2017 Published: 01.01.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION rotection net fences play an essential role to reduce rockfall risk of infrastructure, roads and residential areas against rockfall within acceptable values. Since their installation requires important investments for public administrations, procedures have been developed to quantitatively evaluate risk reduction obtained with these devices and to allow a comparison with other technical solutions for an optimal choice [1-5]. Moreover, the presence of already installed protection devices on the slope has to be considered in the risk assessment and their efficacy in time has to be correctly evaluated, in order to do not overestimate or underestimate their effect [6-8]. Therefore, it is very important for these evaluations to take into account maintenance issues with the aim of evaluating how time and ageing influence efficiency of net fences since public administrations are interested in assessing how long a certain investment ensures the needed risk mitigation. This evaluation allows them to schedule an appropriate maintenance management, taking into account available resources. Despite the highlighted relevance of the influence of damages induced by ageing and installation problems on the behavior and efficiency of rockfall protection net fences, there is a lack of data in technical literature on this topic. Moreover, there is currently no predictive method that could be used to estimate the performance of damaged rockfall protection fences and there is great difference in the technical recommendations for the maintenance provided by producers. P