Application Geological Strength Index (GSI) quantification method on the characterization of carbonate rock mass

Abstract Determining GSI as a representation of the presence of rock mass in slope analysis continues to develop. The development of the quantitative GSI method was carried out because the basic (qualitative) GSI values were deemed too subjective so the results from the use of the quantitative GSIwere expected to be more objective and accurate. The method used is to combine 3 GSI quantitative methods to find GSI based on surface conditions and joint structure. The results showed that the Quantitative GSI value was smaller than the GSI predictive value (qualitative). The GSI approach with RQD and UCS parameters is also presented to describe rock mass conditions due to changes in GSI values, and the third result shows a directly proportional relationship, the greater the GSI value, the greater the RQD and UCS values. The combined application of these three quantification methods is suitable for slopes that have not been properly exposed so that surface and structural conditions can only be seen from visual observations of outcrops and some initial construction slopes.