Resilient design of landslip prevention measures: a case study

Bervie Braes is a 750 m long, and up to 55 m high, coastal slope above a residential area and harbour in Stonehaven, Scotland, with a history of instability mostly associated with the road traversing the slope. This paper outlines the most probable causes of the instability on the slope and details the hazards that had to be taken into account during the design and construction of stabilisation measures. The hazards associated with hydrology in terms of future potential change in rainfall patterns and intensity, but also in terms of providing adequate drainage capacity and flows, were juxtaposed against the geotechnical hazards of shallow landslips and erosion near the surface, as well as deep-seated landslides on the slope. Owing to the complex nature of the hazards and the need for longer life expectancy of the design, the soil nailing option was combined with eco-engineering strategies to provide resilience for a changing climate. A risk-based approach considering the number of lives at danger during a catastrophic failure was adopted when deciding on the priority of the areas of the slope to be stabilised. The sustainability of the design solution and the construction methods were constantly monitored and re-appraised throughout the project.