ABSTRACT
This chapter reviews some of the methods of cautious blasting and describes the rock mass damage from a rock mechanics point of view. After a rock blasting operation is completed, the remaining rock mass itself is very often a part of a structure that is expected to remain stable for a long time. The required stand-up time, that is, the time the rock mass remains stable, depends on the purpose for which the structure is intended. The strength and stability of the rock mass surrounding large, permanent, underground storage rooms is of major importance to prevent rock fall that could badly damage people and equipment. The chapter describes the method for calculating the rock damage which is based on the intensity of blast vibration in the adjacent rock mass. It describes how certain diagrams can be used to compute the damage zone in the remaining rock adjacent to a row of contour holes.
