Construction of subway systems for underground highways, railways and mass transport, hydroelectric installations, -water diversion system etc are. some of the most important infrastructure projects for any country. The blasting engineers ultimate challenge is to provide desired fragmentation with sufficient advance/progress and at the same time keeping ground vibration level within limit as per prevailing law. In this article the author tries to discuss the best possible explosives available for undertaking such a important job (i.e., emulsion Explosives and its superiority over other form of explosives available) and. various blast designs, sequence of excavation, types of strata encountered and steps required for its control, sequence of delays to be used in blasting etc. Regarding controlled blasting for carrying out ideal blast in tunnel, i.e., to blast in such a way that minimum of damage to the rock that remains and a minimum of over break is made. This has many advantages like, less rock damage to achieve greater stability and requirement of less ground support, safer tunneling operation as less scaling is required, less over break makes a smoother hydraulic surface for an unlined tunnel and less concrete required to fill excess void created by over break.
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