Flexible steel protection systems against natural hazards are difficult to access in mountainous areas and inherently become difficult to monitor and maintain over the years. Many small-scale events, such as rock-fall below the service energy limit (SEL) defined by the EAD 340059-00-0106 or debris flows under the maximum impact pressure of the net, acc. to EAD 340020-00-0106, go unnoticed, but the repetition of several events into a protection system still needs regular maintenance to guarantee full performance in case the design event occurs. Furthermore, experience has shown that the corrosion can vary strongly in small localised areas and lead to unpleasant surprises. Therefore, the understanding of microclimates favorable to the corrosion process needs to improve. A newly developed IoT device, called GUARD, was developed aiming to provide monitoring of flexible steel protection systems. It is equipped, amongst others, with a rope force sensor and an accelerometer. The second target of the device is to pass from repair and pre-ventive maintenance to the concept of predictive maintenance by evaluating the local corrosivity and the associated lifetime of the protection system with a specially developed corrosion sensor. These sensors have been deployed over the past years on 40 sites in 13 countries in Europe. Even many flexible protection barriers are equipped with GUARD in North America, Hawaii, Australia and New Zealand. This contribution aims to highlight the monitoring with the GUARD and the inspection concept that can be developed from it, with a highlight on the data collected so far.

IoT device, flexible protection system, GUARD, predictive maintenance