The Geological Strength Index Chart Assesment For Rock Mass Permeability

Authors : Ali Kayabaşi

Pages : 295-309

View : 8 | Download : 6

Publication Date : 2017-12-03

Article Type : Research

Abstract :Determination of permeability of rock masses without testing is very chalenging due to the presence of complex discontinuity patterns in rock masses. Many empirical approaches were proposed in the literature for estimation of rock mass properties. However, approaches based on rock mass classification systems in determination of rock mass permeability in the literature are rarely encountered. Considering this lack in the literature, in this study, the use of the Geological Strength Index (GSI) chart which is one of the input parameters of the Hoek-Brown empirical failure criterion has been assessed for rock mass permeability. In this study, 365 lugeon test results were used. These data were obtained from various dam sites and a coal mine in Turkey. Firstly, lugeon test results were plotted on the quantitative GSI chart by considering the Surface Condition Rating (SCR) and Structure Rating (SR). Then, different permeability regions on the GSI chart were defined for the rock mass permeability. In this study, the data were obtained from granite, diorite, volcanic breccia, andesite and agglomerate type of rock masses. The proposed rock mass permeability (RMP)- Geologic Strength Index (GSI) chart needs development with other study supports. Morever, RMPGSI chart should not be used for rock types having a soluble character such as limestone and gypsum since they may include karstic zones.
Keywords : Permeability, GSI, Rock mass, Lugeon