基于小波包分析的建(构)筑物爆破振动安全判据研究

基于现场实测爆破振动数据,采用小波包分析技术对爆破振动信号进行了时频特征分析。根据小波包变换的分层分解关系,推导出爆破振动信号不同频带的小波包频带能量,小波包频带能量能同时反映爆破振动三要素(振动的强度、频率和持续时间)的作用影响。从结构动力响应角度,探讨了受控建(构)筑物本身的固有特性对爆破振动动态响应的影响,获得了受控建(构)筑物在爆破振动作用下的频带响应系数。首次建立了能考虑爆破振动的强度、频率和持续时间以及受控建(构)筑物本身的动态响应特性(固有频率和阻尼比)等因素综合的安全判据--响应能量判据,并用工程实例验证了该判据的可行性和可靠性。

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.