Rock slope assessment using kinematic and numerical analyses

Abstract

This paper presents stability assessment of rock slopes at Jalan Kuari, Cheras, Kuala Lumpur. The site is a disused quarry slope where a low cost residential area of Pangsapuri Intan was built very close to it, frequent instability at the rock slope have been reported. A detailed discontinuity assessment was carried at the site, then, the kinematic and numerical analyses were performed in order to determine the stability of the rock slope. The kinematic analysis was carried out using DIPS 5.0 software and the results showed that about 19% is the percentage of the wedge failure that is encountered for the rock slope. Meanwhile, the finite element method of analysis in Phase2 showed that the slope is in stable condition, with the Strength Reduction Factor (SRF) of 2.0. The difference between the results of the kinematic and the finite element analyses is because, the kinematic analysis considered the discontinuities volume and orientations with regards to the slope face, while the finite element, analysed the slope with respect to strength properties. Since the slope is a disused quarry, where previous blasting work had produced fractures on the rock face, these discontinuities and fractures are more influencing the instability and the result from kinematic analysis shows a good agreement with the field observation.