hard rock mass of a tunnel
digital fractured rock mass model
fractured rock mass seepage
jointed and fractured rock mass
parameters characterization of fractured rock mass
random fractured rock mass
alternatively distributed soft and hard rock
deep-hole hard rock drilling
ground consisting of hard rock
HARD ROCK
火成岩
秦岭隧道
硬石岩
硬质岩石
硬岩石
坚岩
硬岩
硬质岩
坚硬岩石