Finite element study of the Nevis Bluff (New Zealand) rock slope failure

Abstract

Finite Element Study of the Nevis Bluff (New Zealand) Rock Slope Failure: In June 1975, part of the Nevis Bluff rock slope failed along State Highway 6 in the South Island of New Zealand. The slope is near the bottom of the Kawarau River valley, which has been deeply entrenched in chlorite schist rocks. The detailed geology of the slope, and the mechanical properties of the rocks comprising the slope are described. For the purposes of finite element modelling, the schist was assumed to be a transversely isotropic material with four independent deformability parameters. A two dimensional finite element program was used to establish the regional state of stress, the results from which were then used in a larger scale model of the rock slope. The results of finite element analyses suggested that slope failure occurred by flexural toppling, where continuous columns broke in flexure as they slid along schistosity surfaces. Flexural cracking was then responsible for propagating the plane along which sliding occurred. When the shear strength available along this plane was exceeded by shear stresses, the slope failed. © 1980 Springer-Verlag.