STATISTICAL ANALYSIS OF ROCK MASS CONSTANTS BY NATM

Statistical analysis of the lock mass constants (mass density, compressive strength, Young modulus and Poissonʹs ratio) of the tunnels which were made by the New Austrian Tunneling Method (NATM) in Japan, was performed on more than 450 sets of data. Based on these studies, an estimation method for the values of the rock mass constants is proposed. This estimated method not only gives the values of rock mass constants but is also applicable in numerical analysis, especially in stochastic finite element method.