基于声波频谱特征的岩体爆破累积损伤效应分析

发布时间：2018-05-04 14:29

本文选题：岩石力学 + 爆破损伤　；参考：《岩土力学》2017年09期

【摘要】：为深入揭示岩体爆破累积损伤效应及其与岩体声学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,并开展了岩体损伤现场声波测试。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,分析了声波主频、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,同时探讨了围岩松动圈厚度、声波换能器间距、爆心距等因素的影响。研究结果表明,随爆破次数增加,岩体爆生裂隙不断增加和扩展,声波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;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;随爆心距增大,岩体声波频谱变化程度逐渐减弱。声波换能器间距越大,声波主频变化越大,频域内最大振幅衰减变化越显著。研究成果对于丰富和完善岩体爆破累积损伤效应声学研究方法具有一定的参考意义。
[Abstract]:In order to reveal the accumulative damage effect of rock mass blasting and its internal relation with rock mass acoustics, 10 small explosive explosions were carried out in the surrounding rock of an underground engineering, and sound wave test was carried out in the field of rock mass damage. Based on the 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 the main frequency of acoustic waves and the maximum amplitude in frequency domain with the increasing of blasting times are analyzed. At the same time, the influence of the thickness of surrounding rock loose circle, the distance of acoustic transducer and the distance of detonation center are discussed. The results show that with the increase of blasting times, the explosive cracks in rock mass increase and expand, the high frequency components of acoustic signals are absorbed continuously, the proportion of low frequency components increases, the main frequency shifts to the low frequency direction, and the distortion degree of the spectrum curve increases. The acoustic wave frequency ratio and the frequency domain maximum amplitude ratio both show a nonlinear decreasing trend. The sensitivity of the frequency domain maximum amplitude ratio is higher than that of the acoustic wave main frequency ratio, and the variation degree of rock mass acoustic wave spectrum decreases with the increase of the core distance. The larger the distance between acoustic transducers, the greater the variation of the main frequency of the acoustic wave, and the more significant the change of the maximum amplitude attenuation in the frequency domain. The research results have certain reference significance for enriching and perfecting acoustical research method of rock mass blasting cumulative damage effect.
【作者单位】：郑州大学土木工程学院;
【基金】：国家自然科学基金资助项目(No.U1504523) 河南省高等学校重点科研项目(No.15A410001)~~
【分类号】：TU45

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