摘要
结构的受震破坏不仅与震动强度有关,而且与震动频率、震动持续时间等因素有关,独立阈值理论的安全评价指标可能会与实际震害情况不符,从能量角度建立爆破震动安全评价指标具有重要意义。提出基于HHT的瞬时能量分析法,首先采用经验模态分解提取爆破震动信号的固有模态函数分量IMF,再对IMF作Hilbert变换计算信号的总输入能量TIE,以TIE作为爆破震动安全评价指标。TIE值在反映现有规程的峰值震动速度指标总体规律的基础上,能够对主频、持续时间因素进行更明确、简洁的定量化描述,具有一定的特色和优势。结合杭州市钱塘江引水工程浅埋段的爆破震动实测资料,验证本文方法的可行性,根据实例计算和爆破震害调查,初步认为当TIE≥1时,爆破震动将对砖混结构造成危害。
Structure damages caused by blasting vibration are not only related to the vibration intensity,but also related to vibration frequency,duration and other factors.The safety evaluation index based on independent threshold value may be inconsistent with the actual damage.Thus,it has important significance of establishing the safety evaluation index of blasting vibration from the energy viewpoint.The instantaneous energy analysis method based on Hilbert-Huang transform（HHT） is proposed.Firstly,intrinsic mode function（IMF） components of blasting vibration signals are extracted.Then,Hilbert transform for IMF is gotten to calculate the total input energy（TIE） of vibration signals.Finally,TIE is used as safety evaluation index of blasting vibration.TIE value not only can reflect the general laws of particle peak velocity（PPV） based on existing specification,but also can give a concise quantitative description for dominant frequency and duration factors.Combining the measured blasting vibration data of shallow-buried section in the Qiantangjiang diversion tunnel project,the feasibility of this method is verified.According to example calculation and blasting damage investigation,the blasting vibration will harm masonry structures when TIE is greater than 1.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2010年第12期2492-2499,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(50509021
51079127)
