Model tests on anomalous low friction and pendulum-type wave phenomena  

作　　者：Hao Wu Qin Fang Yusheng Lu Yadong Zhang Jinchun Liu 

机构地区：[1]Engineering Institute of Engineering Corps. PLA Unitersity of Science and Technology, Nanjing, Jiangsu 210007. China

出　　处：《Progress in Natural Science:Materials International》2009年第12期1805-1820,共16页自然科学进展·国际材料（英文版）

基　　金：supported by the National Natural Sci- ence Foundation of China(Grant No.50525825);the National Basic Research Program of China(Grant No. 2009CB724608);the Natural Science Foundation of Jiangsu Province(Grant No.BK2008002).

摘　　要：The anomalous low friction （ALF） and pendulum-type wave （μ wave） phenomena were two typical, nonlinear, geo-mechanical, and dynamic responses in deep-block rock mass discovered from in situ observations, which occurred from the movement of the geo-blocks under the impact of external pulses, such as deep confined explosion, earthquake, and rock bursts. With the aim to confirm the existence of the above two phenomena and study the variation laws of them experimentally, laboratory tests on the granite and cement mortar continuum and blocks models were conducted on the self-independently developed multipurpose testing system, respectively. The ALF phenomenon was realized under two loading schemes, the blocks model and working block were acted upon by the joint action of vertical impact and horizontal static force as well as the joint action of both vertical and horizontal impacts with different time intervals. It revealed that the discrete time delays corresponding to the local maximums and minimums of the horizontal displacement amplitudes and residual horizontal displacements of the working block satisfied the canonical sequences with the multiple of √2, most of which satisfied the quantitative expression （√2）Δ/Vp. Besides, the one-dimensional impact experiments were carried out on the blocks granite model, continuum, and blocks cement mortar models, respectively. Based on the comparison and analysis of the propagation properties （amplitudes and the Fourier spectrums of acceleration time histories of blocks） of the 1D stress wave in the above models, it is indicated that the fractures in rock mass have tremendous effect on the attenuation of acceleration amplitudes and high-frequency waves. By comparison of the model test data with the in situ measurement conclusions, the existence of the μ wave was confirmed experimentally in the cement mortar blocks model with larger dimensions, and the frequencies corresponding to the local maximums of spectral density curves of three-directional accelerat异常低磨擦( ALF )和现象是的摆钟类型波浪(μ波浪)在深块的岩石质量中的二典型、非线性、geo机械、动态的回答从在 situ 观察发现了，它在外部脉搏的影响下面从geo块的运动发生了，例如深限制的爆炸，地震，和岩石爆炸。与目的到证实上述二现象的存在并且试验性地学习他们的变化法律，臼连续统和块建模的花岗石和水泥上的实验室测试分别地在自我独立地发达的多种用途的严峻的系统上被进行。ALF 现象在二装载下面被认识到计划，块模型和工作的块被扮演在之上由象有不同时间间隔的垂直、水平的影响的联合行动一样的垂直影响和水平静态的力量的联合行动。它表明相应于工作的水平排水量堵住的水平排水量振幅和剩余的本地最大值和最小的分离时间延期满足了正规序列与其大多数满足了量的表示多重。而且，一个维的影响实验在水泥臼分别地建模的块花岗石模型，连续统，和块上被执行。在上述模型基于 1D 压力波浪的繁殖性质(振幅和块的加速时间历史的 Fourier 系列) 的比较和分析，在岩石质量中的破裂在加速振幅和高周波的波浪的变细上有巨大的效果，这被显示。由模型测试数据与的比较在里面 situ 测量结论，μ波浪的存在在块与更大的尺寸建模的水泥臼试验性地被证实，并且相应于本地最大值的频率光谱亚块的三方向性的加速时间历史的密度曲线也满足了几个正规序列与多重。

关 键 词：Deep-block rock mass： Block-hierarchical structure Anomalous low friction Pendulum-type wave Canonical sequence 

分 类 号：N[自然科学总论]