464 Questions 15.7 - 7 5.1 0: excavation principles
Draw a sketch of these three effects and explain why they cause a
so-called Excavation Disturbed Zone (EDZ).
415.10 (a) Can drill and blast excavation rates be significantly increased
from those currently achieved?
(b) Can tunnel boring machine penetration rates be significantly in-
creased?
(c) Are new methods of excavation likely to be introduced?