Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : July 10, 2017 - July 12, 2017
This paper describes the theoretical optimal time-gap of delay blasting in tunnel blasting method. for tunnel blasting. Recently the shorter time-gap of the delay blasting in micro seconds can be carried out by the development of high precious electric detonator. At many excavation sites the time-gaps were empirically determined and there is no report about theoretical determination for the time-gap. At first we introduce a condition for optimal time-gap to reduce synthesized signal in maximum under the assumption that the signal can be expressed by sinusoidal signal without decay. Next the condition is also useful to determine the time-gap for decayed sinusoidal signals. Moreover, we apply the condition for the optimal time-gap to reduce the synthesized signal based on the first blasting signal which is excluded from the actual blasting sound. It is concluded that the time-gap determined by the introduced condition is useful to reduce the synthesized signal.
