Modelling discontinuity control on the development of Hell’s Mouth landslide

Abstract This paper focuses on numerical modelling and back analysis of the Hell’s Mouth landslide to provide improved understanding evolution a section north coast Cornwall, UK. Discontinuity control is highlighted through formation ‘zawn’ or inlet, occurrence two successive landslides evidence ongoing instability opening tension cracks behind cliff top. Several integrated remote sensing (RS) techniques have been utilised for data acquisition characterise slope geometry, features crack extent development. In view structural rock failures, 3D distinct element method (DEM) code incorporating discrete fracture network rigid blocks has adopted stability analysis. The onset modelled failure zones also studied by analysing displacements adjoining blocks, between which, joint-related developed. addition, sensitivity undertaken further insight into influence key discontinuity parameters (i.e. dip, dip direction, persistence friction angle) this coastline. Numerical field observations indicate that block removal preferential erosion along fault resulted in inlet. development inlet provides daylighting conditions discontinuities exposed wall, triggering initial which occurred 23 rd September 2011. modelling, from video landslide, suggests characterised combination planar sliding, wedge sliding toppling modes controlled geometry.