Abstract:

The smooth blasting parameters were researched in deep damaged rock tunnel in order to enhance its adaptability. Based on the theory functioned together by explosion shock wave and explosive gas-pressure, as well as the effect of high static stress and rock damage were also in consideration, parameter calculation formula of smooth blasting under the condition of deep damage rock mass tunnel was proposed through analyzing static stress in burden of perimeter, smooth blasting mechanism and vibration damage characteristics. The result shows that: (1) High rock static stress is equivalent to increasing of rock tensile strength, which make against to formation and transfixion of initial cracks, thus the hole space should be reduced. (2) After the rock was damaged, hole space of smooth blasting and the resistance line value can be appropriately increased while the other conditions are still the same. (3) Under the condition of high rock static stress and damage, surrounding rock with low stability can be easy damaged after smooth blasting when hole space is small. Therefore, the surrounding rock should be reinforced in time to ensure construction safety and rock mass stability as the blasting was improved. (4) The calculation formula of smooth blasting parameters proposed is proved to be valid and adaptable for complex rock environment in on-site blast operation.

Key words: blasting damage, smooth blasting, parameters calculation, initial rock mass stress