Abstract
A statistical reconsideration on the parameters for geomechanics classification of rock mass has been carried out to apply them in the Japanese geological conditions.
Procedure to produce the parameters from the data base collected in conjunction with tunnel deformation and geomechanical rock conditions is reported.
Analysed results of 152 examples of tunnel excavation in the Japanese geology so far collected are compared with the weighting of classifications by Wickham, Bieniawski and Barton.
The authors concluded that the greatest weight should be placed on the thickness of tunnel overburden presented by the sectional area of tunnelling, whereas the RQD and joint condition constitute the greatest factor in the aforesaid researchers.
