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Abstract The rock mass around blasting hole will be damaged when foundation pit is excavated by blasting. Therefore，it is very important to control safety of blasting excavation in order to ensure the bedrock quality. Based on bedrock blasting excavation in Ningde Nuclear Power Plant，the attenuation laws of site blasting vibration is obtained through in-situ test；and the relationship between damage depth caused by blasting and peak particle vibration(PPV) of rock mass 30 m away from the blasting center is established through the site monitoring and numerical simulation. Accordingly，velocity threshold is determined based on different allowable damage depths of foundation pit excavation by blasting. It is shown that controlling method and velocity thresholds effectively ensure safety of the bedrock under blasting excavation.
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Received: 24 April 2009
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