Use of Field Data in Determining Rock Slope Stability: Case Study North – South Malaysia Highway

Abstract

This study was conducted to assess the rock mass classification and to evaluate the stability of a slope at the North – South highway (KM 173.7 between the Parit Buntar interchange and interchange at Jawi). A number of field data were collected at the site which include dip direction, dip angle, type of fractures, weathering state and length of fractures, ground water condition and uniaxial compressive strength of rock. The classification of rock mass is based on the Bienawski and Laubscher classification method while stereographic projection is used to assess the rock slope stability. It can be concluded that based on Bienawski the existing rock slope is in a very good condition (1st class) and while Laubscher dictates the rock as in good condition (2nd class). The contour density in the stereographic projection also indicates that the overall rock blocks are in stable condition geometrically. There are three sets of fractures present in the slope which generally dip in the NW – SE, N – S and E – W directions. The type of failure, if it were to occur, would be a wedge type. However, this study does not take into account factors like the shear strength of a joint and the dip of the intersecting line between two joints.