Integrated risk assessment due to slope instabilities at the roadway network of Gipuzkoa, Basque Country

Abstract

Transportation corridors such as roadways are often subjected to both natural instability and cut slope failure, with substantial physical damage for the road infrastructure and threat to the circulating vehicles and passengers. In the early 2000s, the Gipuzkoa Regional Council of the Basque country in Spain, marked the need for assessing the risk related to the geotechnical hazards at its road network, in order to assess and monitor their safety for the road users. The Quantitative Risk Assessment (QRA) was selected as a tool for comparing the risk 20 for different hazards on an objective basis. Few examples of multi-hazard risk assessment along transportation corridors exist. The methodology presented here consists in the calculation of risk in terms of probability of failure and its respective consequences, and it was applied to 95 selected points of risk (PoR) of the entire road network managed by the Gipuzkoa Regional Council. The types of encountered slope instabilities which are treated are rockfalls, retaining wall failures, slow moving landslides, and coastal erosion induced failures. The proposed 25 methodology includes the calculation of the probability of failure for each hazard based on an extensive collection of field data and its association with the expected consequences. Instrumentation data from load cells for the anchored walls and inclinometers for the slow moving landslides were used. The expected road damage was assessed for each hazard level in terms of a fixed Unit Cost, UC. The results indicate that the risk can be comparable for the different hazards. 12% of the PoR in the study area were found to be of very high risk. 30

Intervention Solutions on Landslides in Road Areas. Case Study

“…They are caused by triggering factors such as torrential rains, water leaks, earthquakes or human interventions on the relief, due to lower characteristic parameters of the soils. Landslides can trigger suddenly, being dangerous to people, properties and communication routes, causing property damage or even loss of human lives [5][6][7][8][9]. The prevention and management of landslides requires continuous planning and monitoring, as well as rapid physical interventions to stabilize the area, through the construction of various support structures or through technical interventions on the foundation soils.…”

Small-scale analysis to rank municipalities requiring slow-moving landslide risk mitigation measures: the case study of the Calabria region (southern Italy)

“…Owing to their particular kinematic features, associated with a permanent or episodic activity, these landslides mainly cause direct damages to exposed buildings and/or infrastructure networks the severity of which progressively increases over time (Antronico et al 2015;Ferlisi et al 2021;Peduto et al 2017). Consequently, also the SML-induced risk increases with detrimental effects on the abovementioned exposed elements that are expected to be higher as displaced masses experience sudden accelerations due to rainfall or earthquakes (Donnini et al 2017;Gullà 2014;Mavrouli et al 2019;Negulescu et al 2014;Uzielli et al 2015).…”