Author: Dato’ Ir. Dr. Dennis Ganendra, Ir. Lam Yoon Cheong, Koay Leong Thye
Presented at: International Conference on Landslides and Slope Stability (SLOPE 2019), September 2019
The effects of weathering of rock mass and its discontinuities is well known in the highly humid Malaysian climate. A pilot study was carried out to assess the stability and risk categorization of rock slopes at a major expressway. The expressway operator was interested to ascertain the risks of slope instability and identification of priority areas for maintenance planning of remedial or mitigation works.
The principal methods to identify potentially unstable rock mass are geological and rock discontinuity mapping, LiDAR survey, kinematic analysis, stability and risk assessment of the slopes. At inaccessible areas, fieldworks were facilitated using roped access technique and a skylift crane.
Geo-structural and discontinuity mapping were carried out to assess the rock mass condition and joint orientations at the slope face. Topographic contours and cross-sections, obtained from LiDAR survey, were used to evaluate the geometric profile of slopes while kinematic analyses were performed to verify the stability of rock face. The likelihood of a slope failure is caused by instability factors such as rock mass and joint conditions, slope angle and kinematic
analysis. The related consequence factors are influenced by slope geometry, height of potential instability and safety features available at the slope.
High risk slopes were prioritized for future remedial works. With visual conditions and mapping data recorded in the base photographs, it is possible to continuously monitor the slopes over time, thereby providing a versatile tool in the long-term asset management of the expressway.
Location : MALAYSIAN EXPRESSWAY