Rapid Design of a Modular Rockfall Protection Wall in Response to the 2016 KaiKoura Earthquake

The November 2016 M 7.8 Kaikoura earthquake caused thousands of landslides in the northeastern part of New Zealand’s South Island. More than 80 landslides directly impacted a coastal road and rail transportation corridor, resulting in closure of a critical national transportation corridor for 13 months. A key part of the work to restore the route involved mitigating the rockfall risk posed by unstable slopes. This included installing more than 80 rockfall protection structures along the base of the slopes. In a few areas, slope conditions and space constraints meant that existing rockfall protection solutions could not be readily utilized in the narrow space available. A new type of modular rockfall protection wall, comprised of interconnected concrete blocks and sand and rock-filled gabion baskets, was designed, tested, and approved for use on site. Two of these walls have been constructed to provide permanent rockfall protection to users of this important transportation link.