| 位置条件对爆破震动信号分析中小波包时频特征的影响 |
| |
| 作者单位： | ;1.北京理工大学!北京100081;2.西安科技学院!西安710054;3.北京理工大学!北京100081 |
| |
| 摘 要： | 爆心至测点的位置条件是影响爆破震动时频分布的主要因素之一。在考虑到段药量变化的情况下,位置条件由比例距离和高差系数来进行量化。运用小波包分析方法对监测获得的爆破震动信号进行时频特征分析,探讨时频分布与比例距离及高差系数之间的关系。试验研究发现,位置条件对震动波形小波包细节信号时频特征的影响主要体现在峰值质点振速、优势频率大小及波形衰减阻尼比的变化上。其中峰值质点振速随比例距离的增加呈指数衰减,其与高差系数的相关规律性不强;优势频率随比例距离增加也呈衰减趋势,高差系数对其有较大影响,但规律不明显;衰减阻尼比在不同的主振频带内与比例距离及高差系数有不同的关系,较低频率部分其阻尼比随着比例距离的增加而增大,较高频率部分则基本保持不变。
|
| 关 键 词： | 位置条件 小波包分析 时频特征 比例距离 衰减阻尼比 爆破震动 |
AN EXPERIMENTAL STUDY ON GROUND VIBRATION FROM MILLISECOND BLASTING WITH TWO SOURCES NEAR TO THE GROUND SURFACE |
| |
| Affiliation: | ,School of Civil Engineering and Architecture,Wuhan University of Technology |
| |
| Abstract: | An experimental method, by which the vertical component of ground vibration velocity from a millisecond blasting with two sources near to the ground surface can be measured, is suggested. The measured results at measuring points apart 10, 20 and 40m from the blasting centre are given when the delayed time is 20, 40, 60 and 80ms. Through theoretical analysis, the distribution rules of vibration velocities in vertical direction and their power spectra are obtained. The experimental results show that the optimal delayed time exists when the millisecond blasting is used for reducing blasting seismic strength. |
| |
| Keywords: | Millisecond blasting Ground vibration Blasting seismic effect Random vibrat0 |
|
|
