Rock Slope Stability Assessment of Limestone Hills in Northern Kinta Valley, Ipoh, Perak, Malaysia

Abstract

The uniqueness of the karst topography of Kinta Valley is the result of the spectacular shaped steep-sided limestone towers. The instability of these hillslopes however, may affect the vulnerability of the surrounding area. This paper presents the results of slope stability assessment by using kinematic analysis to investigate the possible failure modes of 7 slopes in Gua Naga Mas (GNM1, GNM2 and GNM3), Gua Kandu (GK1, GK2 and GK3) and Gua Tempurung (GT) located in the southern part of the Kinta Valley, Ipoh, Perak. From the results of the slope stability assessment, it was determined that planar failure and wedge failure were the main failure modes. The GNM1 slope of Gua Naga Mas consist of four wedge failures and a planar failure with dip directions/dip angles of 005°/54°, 354°/59°, 124°/52°, 360°/50° and 063°/70° respectively. The GNM2 slope consists of a wedge failure with the dip direction/dip angle of 021°/64°. Two wedge failures and a planar failure were identified on slope GNM3 with the respective dip directions/dip angles of 336°/49°, 301°/68° and 270°/71°. The GK1 slope for Gua Kandu consists of wedge and planar failures with dip directions/dip angles of 231°/49° and 217°/49° respectively. The mode of failure at GK2 slope was identified as wedge failure with the dip direction/dip angle of 154°/44°. No mode of failure was identified on slope of GK3. Slope GT of Gua Tempurung was identified to have two wedge failures with dip directions/dip angles of 011°/49° and 321°/48° respectively.