具有梯度静应力的红砂岩应力波衰减特性试验研究  

Experimental study on attenuation characteristics of stress wave in red sandstone with gradient static stress

作　　者：金解放[1] 刘康 张雅晨 王熙博 张睿 石子勃 徐虹 JIN Jiefang;LIU Kang;ZHANG Yachen;WANG Xibo;ZHANG Rui;SHI Zibo;XU Hong(School of Civil and Surveying Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;College of Resources sources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西赣州341000 [2]江西理工大学资源与环境工程学院,江西赣州341000

出　　处：《中南大学学报（自然科学版）》2023年第6期2482-2495,共14页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51964015,52174112);江西理工大学清江青年英才支持计划项目(JXUSTQJBJ2017007)。

摘　　要：地下工程围岩体承受梯度应力,导致围岩体在梯度空间上的孔隙度不同,影响应力波在其传播的衰减特性。为研究梯度应力对岩石应力波传播衰减特性的影响,利用改进的SHPB试验装置,对红砂岩试件进行不同静应力梯度工况下的应力波传播试验。将采集得到的波形时域数据分别进行傅里叶变换和小波包分解重构。分析应力波质心频率和频带能量分布与静应力梯度的关系,构建频域特征参数的演化经验模型,表征梯度静应力下岩石中应力波的衰减与频散特性。研究结果表明:应力波频谱幅值和应力波信号能量都主要集中于低频带,其中,频带0~7.81 kHz的能量占总能量的80%左右。梯度静应力作用时,岩石中的应力波质心频率随传播距离增加呈线性增加,在同一测点处,应力波质心频率随应力梯度的增加呈“先增加后减小”的变化趋势;在梯度静应力作用下,岩石应力波的频谱峰值衰减呈先快速下降再平稳发展的趋势;岩石应力波总能量与传播距离的幂函数呈线性变化;在梯度静应力作用下,应力波的频带能量和质心频率随传播距离的增加由低频带向较高频带偏移。研究结果阐释了梯度应力的围岩体中应力波的传播衰减规律,从频域的角度指出了应力波在具有梯度应力环境下的传播衰减特性。In underground engineering,the surrounding rock mass is subjected to gradient stress,resulting in different porosity of the rock mass on the gradient space,which affects the attenuation characteristics of the stress wave in its propagation.To explore the effect of gradient stress on the attenuation characteristics of rock stress wave propagation,a modified SHPB test device was employed to conduct stress wave propagation tests on red sandstone specimens under different static stress gradient conditions.The waveform time-domain data of the stress wave was obtained.The time-domain waveform data were respectively subjected to Fourier transform and wavelet packet decomposition and reconstruction.The relationship among the centroid frequency and frequency band energy distribution of stress wave and the static stress gradient were analyzed,respectively,and the evolution empirical model of the characteristic parameters in the frequency domain were built to characterize the attenuation and dispersion characteristics of the stress wave in the rock under the gradient in-situ stress.The results show that the stress wave spectrum amplitude and stress wave energy are mainly concentrated in the low frequency band with the frequency band 0-7.81 kHz accounting for about 80%of the total energy.Under the action of gradient static stress,the centroid frequency of stress wave in the rock increases linearly with the propagation distance.At the same point,the centroid frequency of stress wave in rocks tends to"increase and then decrease"while the stress gradients increase.The decay of the peak spectrum of rock stress waves under gradient static stress tends to decrease rapidly before developing smoothly,and the total energy of rock stress waves varies linearly as a power function of the propagation distance.The band energy of the stress wave under gradient static stress is shifted to the right as a whole with the increase of the propagation distance,which also indicates the development of the centroid frequency towards the high frequen

关 键 词：应力波传播 梯度应力 衰减与频散 频谱分析 频带能量分布 

分 类 号：TU45[建筑科学—岩土工程]