首页|具有复杂层次结构的二维离散块系岩体中摆型波与旋转波研究

具有复杂层次结构的二维离散块系岩体中摆型波与旋转波研究

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岩体是由软弱结构层分割的各种尺度的岩块相互嵌套形成,具有复杂的层次结构,对岩体动力变形及应力波传播具有显著影响.针对具有复杂层次结构的块系岩体,基于Cosserat理论建立摆型波与旋转波的动力模型,确定层次结构对动力变形的影响.进一步,针对摆型波的低频、低速特征,基于Bloch定理确定并求解不同层次结构中波的频散方程,研究波的频散关系及速度特征.最后,基于固体能带理论揭示摆型波低频特性的力学机制,并基于研究结果讨论摆型波及旋转波诱发冲击地压的可能性.研究表明:忽略岩体高阶层次结构将低估岩体的位移及其整体变形,计算结果偏于不安全.长波扰动作用下,高阶层次结构中第一模态摆型波(对应声学支)频散现象不显著,其传播速度降低,岩体内部高阶层次结构阻碍波的传播;其他波(对应光学支)频散现象极其显著,几乎不能独立存在并传播;低频摆型波为波的主要形式,比高阶模态波及传统的P波、S波衰减速度更慢、传播距离更远.
Research on pendulum-type and rotational waves in 2D discrete blocky rock masses with complex hierarchical structures
Rock masses consist of nesting rock blocks with various scales separated by weak structural layers,and their complex hierarchical structures play a significant role in dynamic deformation and stress wave propagation.In this paper,based on the Cosserat theory,a dynamic model of pendulum-type and rotational waves in blocky rock mass with complex hierarchical structures is established to determine the influence of hierarchical structures on dynamic deformation.Then,aiming at low-frequency and low-velocity characteristics of pendulum-type waves,dispersion equations of waves are determined and solved in different hierarchical structures based on the Bloch theorem,and furthermore,the dispersion relation and velocity characteristics of waves are investigated.Finally,mechanism of low-frequency characteristics of pendulum-type waves is revealed on the basis of solid energy band theory,and the possibility of pendulum-type and rotational waves inducing rock bursts is discussed based on the research results.It is indicated that ignoring higher-order hierarchical structures of rock masses may underestimate displacement and overall deformation of rock masses,resulting in unsafe numerical results.Under the action of long wave disturbance,for the first mode pendulum-type waves(the acoustic branches),the dispersion is not significant and propagation velocity decreases,and higher-order hierarchical structures inside rock masses hinder the wave propagation.However,the dispersion of other waves(the optical branches)is significant so that they hardly exist and propagate independently.The low-frequency pendulum-type waves are dominant,which have slower attenuation and longer propagation distance than the high-order mode waves and traditional P and S-waves.

rock mechanicsblocky rock massespendulum-type wavesrotational waveshierarchical structuresdispersion relationCosserat theory

姜宽、卢春生、戚承志、王泽帆

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北京工业大学城市建设学部,北京 100124

西澳大学土木、环境与采矿工程学院,澳大利亚珀斯6009

科廷大学土木与机械工程学院,澳大利亚珀斯6845

北京建筑大学北京未来城市设计高精尖中心,北京 100044

北京建筑大学城市交通基础设施建设北京国际科技合作基地,北京 100044

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岩石力学 块系岩体 摆型波 旋转波 层次结构 频散关系 Cosserat理论

国家自然科学基金资助项目国家自然科学基金资助项目国家留学基金管理委员会资助项目

5177401812172036202206540052

2024

岩石力学与工程学报
中国岩石力学与工程学会

岩石力学与工程学报

CSTPCD北大核心
影响因子:2.589
ISSN:1000-6915
年,卷(期):2024.43(2)
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