An overview of excavatability classification for bedded and non bedded rock in a tropical region

Abstract

Surface excavation works in tropically weathered rock are often reported to be challenging due to too many uncertainties such as rock mass and rock properties, environment, selection of the best excavation method, machine characteristics, cost and production rate. The purpose of this study is to present an overview of previous assessments of excavatability and demonstrate the reliability of these methods for assessing the weathered state of rocks in tropical regions. In surface excavation operations, the heterogeneity of the rock mass presents significant issues, particularly in sedimentary locations where the same rock mass contains multiple rock layers with varying weathering grades and strengths. Furthermore, the non-bedded rock mass displays a distinct profile, with boulders occurring throughout the entire zone of highly weathered rock. In tropical weathered rocks, the weathering profile of the rock mass can be very erratic, changeable, and dominant in dictating the behavior of the rock. Disputes in rock engineering properties for practitioners involved in construction work, due to weathering and other issues such as the complex behavior of soil-like and rock-like material arise at the site. These disputes affect practitioners working in the field. A critical review of the current excavatability assessment was conducted. The parameters are then contrasted with the current excavatability assessment procedure, and the outcomes are also specified. At the end of the study, the significance parameter on geological, geotechnical, and geophysics could be determined for various types of rock; thus a reliable classification system could be proposed for efficient assessment. Additionally, a classification system that takes into account the geological factors that are important for surface excavation in tropical areas is greatly needed to assess excavatability.