Additional points 283In Chapter 15, we noted that the possibility of introducing new
methods of excavation is unlikely. Similarly, we do not anticipate that
new methods of stabilization will be introduced. Failure of the rock mass
occurs because of the presence of increased rock stresses, pre-existing
fractures, water pressure and water flow, and rock deterioration over
time. It is unlikely that stabilization improvements will be made because
the factors listed above cannot be removed, and the existing techniques
of rockbolts, shotcrete, lining and grouting offer direct solutions to the
adverse effects.