Statistical properties of the Bukit Timah granite in Singapore

The mechanical behavior of rock mass is affected strongly by its material p roperties. This paper carries out statistical analyses of the material prop erties of a rock mass. Statistical analyses of the material constants and t he initial damage parameter of the rock mass are performed by using both fi eld and laboratory test data. Based on the measured properties of rock spec imens, the elastic modulus, uniaxial compressive strength, and the Poisson' s ratio of sock are each found to have normal distributions and the,tensile strength to have the gamma distribution. By using Monte Carlo simulation, the equivalent critical tensile strain is found to have the normal distribu tion. The initial damage of the rock mass, which describes the effects of n aturally existing geological discontinuities in a rock mass, is estimated u sing the field-measured longitudinal and transverse elastic wave velocities . It is found to have the beta distribution. These distributions of rock pr operties can be used in statistical analyses of the rock mass responses to both static and dynamic loads.