梯度应力对红砂岩应力波传播特性的影响研究  

Effect of gradient stress on stress wave propagation characteristics of red sandstone

作　　者：金解放[1] 张雅晨 刘康 张睿 李云浩[1] JIN Jie-fang;ZHANG Ya-chen;LIU Kang;ZHANG Rui;LI Yun-hao(School of Civil and Surveying Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;School of Resource and Environment Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Beijing Urban Construction Exploration&Surveying Design Research Institute Co.,Ltd.,Beijing 100101,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 [3]北京城建勘测设计研究院有限责任公司,北京100101

出　　处：《岩土力学》2023年第4期952-964,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51964015,No.52174112);江西理工大学清江青年英才支持计划(No.JXUSTQJBJ2017007)。

摘　　要：地下工程岩体开挖卸载后,围岩体承受的地应力随空间位置呈梯度形式变化。梯度地应力导致岩石的波阻抗呈梯度形式变化,进而影响应力波传播衰减特性。为研究梯度地应力对岩石应力波传播特性的影响,利用自主研发的具有梯度静应力岩石应力波传播试验系统,对红砂岩长试件进行了9种应力梯度工况下的应力波传播试验。通过分析岩石应力波传播速度、波阻抗随应力梯度的变化规律,构建应力波幅值与传播距离、传播时间和应力梯度之间的经验模型,探索梯度应力影响红砂岩应力波传播衰减的机制。结果表明,相同应力梯度工况下,随传播距离增加,应力波形状变化较小,但幅值逐渐减小。随应力梯度增大,岩石各测点区段内应力波传播速度、波阻抗均增大,但增大速率逐渐减缓,相邻测点区段波阻抗差值比先快速增大,后缓慢减小。随传播距离和传播时间增加,应力波幅值均呈指数形式减小;随应力梯度增大,时空衰减系数均呈先快速增大,后缓慢减小趋势变化。随应力梯度增大,相同测点应力波幅值先快速减小,后缓慢变化,在低应力梯度阶段,距离自由端越远的测点幅值衰减速率越快。After the excavation unloading of underground engineering rock mass, the geostress in surrounding rock mass varies with the spatial position in a gradient form. The wave impedance of rock varies in a gradient form under the action of gradient geo-stress,and then affects the propagation and attenuation characteristics of stress wave. In order to investigate the effect of gradient geostress on the propagation characteristics of rock stress wave, the stress wave propagation tests were carried out on the red sandstone long specimen under nine stress gradient conditions by using the self-developed rock stress wave propagation test system with gradient static stress. By analyzing the variation laws of rock stress wave velocity and wave impedance with stress gradient, empirical models between stress wave amplitude and propagation distance, propagation time and stress gradient were established to explore the mechanism of stress wave propagation and attenuation affected by gradient stress in red sandstone. The results show that under the same stress gradient condition, the stress waveform change little with the increase of propagation distance, but the stress wave amplitude decrease gradually. With the increase of stress gradient, the stress wave velocity and wave impedance in each measuring point section of rock increase, but the increase rate gradually slows down, the wave impedance difference ratio between adjacent measuring point sections increases rapidly first and then decreases slowly. The stress wave amplitude decreases exponentially with the increase of propagation distance and propagation time, with the increase of stress gradient, the spatial-and time-attenuation coefficients of amplitude show a trend of “rapid increases at first, then slow decreases”. As the stress gradient increases, the stress wave amplitude at the same measuring point decreases rapidly first and then varies slowly, and at the low stress gradient stage, the further away from the free end, the faster the amplitude attenuation rate of the

关 键 词：岩石应力波传播 梯度应力 传播速度 波阻抗 幅值衰减 

分 类 号：TU452[建筑科学—岩土工程]