Geospatial analysis in identifying karst cavity distribution: The SMART Tunnel, Malaysia

A methodology has been developed for producing zones of karst cavity distribution based on a geotechnical database containing data from boreholes drilled for a newly developed tunnel, the 9.7 km long Stormwater Management and Road Tunnel (SMART tunnel), where it is predominantly routed in karstified limestone. Preparation of such maps will provide some insight into the characterization of karst, as much of the commercial center of Kuala Lumpur is founded on heavily karstified limestone of the Kuala Lumpur Limestone. For the analysis, the three nearest boreholes were used to represent the percentage of karst in one unit triangle of area and one unit triangle of volume of ground along the tunnel alignment. This reveals the complex nature of the ground that appears to align generally in the heavily karstified limestone at the northern section and in massive, good quality limestone at the southern section of the study area. The results indicate that the spatial distribution of dissolution features is explained mostly by the structural domains, the mineralogical composition, and topography.