岩体爆破累积损伤效应声波频谱特征分析

发布时间：2018-02-17 05:39

本文关键词： 爆破损伤累积效应声波测试频谱特征快速傅立叶变换　出处：《地下空间与工程学报》2017年02期 　论文类型：期刊论文

【摘要】：为揭示岩体爆破损伤累积扩展规律及其与岩体声学变化特性之间的内在联系,在某地下工程围岩中进行了10次小药量爆破岩体损伤的现场声波测试。为充分利用岩体声波测试信号中的有效信息,弥补单纯声波速度分析的不足,基于快速傅立叶变换(FFT)探讨了声波在爆破损伤岩体中传播时的衰减特性,分析了主频、频域内最大振幅等岩体声学参数随爆破次数不断增加的变化特性。研究结果表明,随着爆破次数增加,岩体声波频谱特征呈现如下变化规律:(1)岩体爆生裂隙不断增加和扩展,声波测试信号中的高频成分不断被吸收,低频成分所占比例增加,主频向低频方向偏移,频谱曲线畸变程度增加;(2)声波主频比和频域最大振幅比均呈非线性降低趋势,频域最大振幅比对岩体爆破损伤的敏感性高于声波主频比;(3)随着爆心距的增大,岩体声波频谱变化程度逐渐减弱。
[Abstract]:In order to reveal the cumulative propagation law of rock mass blasting damage and its internal relation with rock mass acoustical variation, In order to make full use of the effective information of rock mass acoustic wave test signal and to make up for the deficiency of pure acoustic velocity analysis, the field acoustic wave test of rock mass damage was carried out in the surrounding rock mass of a certain underground project. Based on fast Fourier transform (FFT), the attenuation characteristics of acoustic waves propagating in damaged rock mass during blasting are discussed. The variation characteristics of acoustic parameters of rock mass such as main frequency and maximum amplitude in frequency domain with the increase of blasting times are analyzed. With the increase of blasting frequency, the frequency spectrum of rock mass acoustic wave presents the following law of change: 1) the crack caused by rock mass explosion is increasing and expanding, the high frequency component of acoustic wave signal is continuously absorbed, and the proportion of low frequency component increases. When the main frequency shifts to the low frequency direction, the distortion degree of the spectrum curve increases. (2) both the principal frequency ratio and the maximum amplitude ratio in frequency domain show a nonlinear decreasing trend. The sensitivity of the maximum amplitude ratio in frequency domain to rock mass blasting damage is higher than that of the main frequency ratio of acoustic wave.) with the increase of the core distance, the frequency spectrum of rock mass acoustic wave becomes weaker.
【作者单位】：郑州大学土木工程学院;郑州科技学院土木建筑工程学院;
【基金】：国家自然科学基金(U1504523) 河南省高等学校重点科研项目(15A410001)
【分类号】：TU452

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