What is the impact of strike direction in Tunnels with Class 5 rock ?

Strike direction will make favor in tunneling if the strike dipping against the tunneling direction, that mean the risk of collapse is very less in class 5. However the strike dipping towards to the tunneling direction will cause high risk levels of collapse so need more care for immediate support works and very less advance in round.   

the impact of strike direction in tunnels depends on physical and chemical proprieties of a rock ,                                                                                                                                      ( porosity, permeability