ROCK SLOPE STABILITY ASSESSMENT OF LIMESTONE HILLS, SOUTHERN KINTA VALLEY, IPOH, PERAK, MALAYSIA

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 005⁰/54⁰, 354⁰/59⁰, 124⁰/52⁰, 360⁰/50⁰ and 063⁰/70⁰ respectively. The GNM2 slope consists of a wedge failure with the dip direction/dip angle of 021⁰/64⁰. Two wedge failures and a planar failure were identified on slope GNM3 with the respective dip directions/dip angles of 336⁰/49⁰, 301⁰/68⁰ and 270⁰/71⁰. The GK1 slope for Gua Kandu consists of wedge and planar failures with dip directions/dip angles of 231⁰/49⁰ and 217⁰/49⁰ respectively. The mode of failure at GK2 slope was identified as wedge failure with the dip direction/dip angle of 154⁰/44⁰. 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 011⁰/49⁰ and 321⁰/48⁰ respectively..