Safety criterion of blasting vibration for structure based on wavelet packet analysis

According to the collected field data of blasting vibration, the time-frequency characteristic analysis for blasting vibration signals is made by use of the wavelet packet analysis technology. According to the multi-resolution decomposition of wavelet packet transform, the wavelet packet frequency band energy is deduced on different bands of blasting vibration signals, and it can reflect the total influence of all the three key elements (the intensity, frequency and duration of vibration) of blasting vibration. Considering the dynamic response of structures, the influence of the inherent characteristics of the controlled structures on the blasting vibration dynamic response is discussed, and the frequency band response coefficients for the controlled structures by blasting vibration are obtained. A safety criterion of multi-factors blasting vibration called response energy criterion is firstly established. The criterion can reflect the total influence of the intensity, frequency and duration of vibration and the characteristics (natural frequency and damping ratio) of dynamic response from the controlled structures themselves, and the feasibility and reliability of the criterion are validated by some practical engineering cases.