Geo-structural stability assessment of surrounding hills of Kuala Lumpur City based on rock surface discontinuity from geological survey data

Abstract

Structural field data have been widely used for geological analysis in the past decade. By contrast, structural stability analysis based on surface orientation for large discontinuity planes has received inadequate attention from researchers. This study performs structural stability analysis on Kuala Lumpur (KL) by utilizing surface orientations (1) to investigate the influence of rock stability on the development of transportation corridors and (2) to assess land and infrastructure stability by determining areas susceptible to various rock failures. Data are collected from three parts of KL (east, west and north) that represent different hilly regions. Data from the southern part of the city are not collected because its hilly regions are far from the city. Furthermore, the orientation data of bedding planes, faults and joints are grouped into sets for a thorough understanding. The computed global mean and best fit show that the overall structure of the area is dome- and basin-shaped. Kinematic analysis provides the percentage of potential risk for various rock failures. Our findings show the dominant types of rock failure with high risk around the city and the ranges of probabilities in the eastern, western and northern part of the city, which are 5.22%, 9.8% and 7.37%, respectively. Low probability of wedge sliding, high probability of flexure toppling and medium probability of planar sliding are observed. Results show that the set S(2) with dip angle 55°–60° in the east of KL; S(3), S(4) with dip angle 58°–67° and 65°–70° in the west of KL and S(2), S(6,7) with dip angle 52°–70° and 86°–90° are critical and could contribute to the slope failure risk in the future. It could be understood that rock failures can seriously influence the development of the surrounding agriculture land and infrastructures.