Parameter Optimization of Presplitting Blasting Based on Model Test

In order to effectively reduce the disturbance derived from the vibration of the presplitting blasting in the slope rock mass and surrounding structures, it is important not only to pay attention to the vibration damping effect of the presplitting, but also to optimize the blasting parameters and initiation modes of the presplitting hole. The study adopts the orthogonal experimental method, which selects the C30 concrete as the similar simulation material of the blasting object to carry out the similar model test of the blasting process with presplitting hole. In this model test, three factors are considered as the non-coupling coefficient, which are delay time, and maximum single-shot charge, and four levels are set for each factor, taking effective half porosity, pre-fracture width and original rock damage rate as evaluation indicators. After the analysis of the sensitivity of each factor to evaluation indicators through range and variance calculations, the best blasting effect with the blasting parameters of the presplitting hole are finally achieved in this model test: non-coupling coefficient is 1.33, delay time is 12 ms, and maximum single-shot charge is 1.8 g. The research results provide guidance for the design of the parameters of on-site blasting with presplitting hole and precise delay time.