第35卷第5期 岩 土 力 学 Vol.35 No.5 2014年5月 Rock and Soil Mechanics May 2014

文章编号：1000－7598 (2014) 05－1317－07

武当群片岩变形参数各向异性特征及机制研究

王章琼1，晏鄂川1，刘毅学2，王忠杰1

（1.中国地质大学 工程学院，武汉 430074；2.湖北省十房高速公路建设指挥部，湖北 十堰 442000）

摘 要：片岩因受片理面影响，其变形行为和破坏机制与一般岩体存在明显差异。为此，采用室内单轴压缩试验，研究了十堰－房县高速通省隧道武当群片岩在片理面倾角分别为0°、45°、90°时的变形参数各向异性特征及破坏机制。结果表明：片岩变形参数及破坏模式具有显著的各向异性特征。按照弹性模量E由大到小的顺序，试样的片理面倾角依次为：90°、0°、45°；按照泊松比v由大到小的顺序，试样的片理面倾角依次为：45°、0°、90°。片理面倾角为0°时试样以垂直片理面方向的压断破坏为主，45°时试样以沿片理面方向的纯剪切破坏为主，90°时以劈裂破坏为主。在此基础上，通过电镜扫描、FLAC3D数值试验结果等，分析了片岩变形破坏各向异性的机制，认为主要原因是片理面空间方位与轴向力方向不同的组合，导致软弱结构面——片理面对片岩变形的贡献差异明显。

关 键 词：片岩；单轴压缩试验；各向异性；破坏机制；电镜扫描 中图分类号：TU 452 文献标识码：A

WANG Zhang-qiong, YAN E-chuan, LIU Yi-xue, WANG Zhong-jie

(1. Faculty of Engineering, China University of Geosciences, Wuhan 430074, China;

2. Hubei Provincial Construction Headquarters of Shiyan-Fangxian Expressway, Shiyan, Hubei 442000, China)

Anisotropic properties of deformation parameters

and its mechanism of Wudang group schist

1

121

Abstract: The common character of schist is transversely isotropic due to the existence of regular bedding planes, which means that the failure mechanism and deformation characteristics of such rocks have the obvious difference with common rocks. In view of this point, uniaxial compressive test on samples of Wudang group schist, Tongsheng tunnel, Shiyan-Fangxian expressway, that with schistosity inclination of 0°, 45° and 90° respectively is carried out. The results show that: deformation parameters and failure mode of schist show obvious anisotropic characteristics. In the order of descending values of the modulus of elasticity, schistosity inclination of the samples are 90°, 0°, 45°respectively, in the order of descending values of the Poisson ratio, schistosity inclination of the samples are 45°, 0°, 90° respectively. The main failure mode is press off perpendicular to the spatial orientation of schistosity, shear and split off when schistosity inclination is 0°, 45°and 90° respectively according to schistosity inclination. Based on above, the mechanism of deformation and failure characteristics of schist is analyzed, via electron microscope scanning and FLAC3D numerical experiment, it is considered that, the main reason is the different relationships between spatial orientation of schistosity and axial force direction, which caused obvious differences of contribution that of schistosity surface to schist deformation. Key words: schist; uniaxial compressive test; anisotropy; failure mechanism; electron microscope scanning

1 引 言

鄂西北地区为国内典型的变质岩发育区，以武当群片岩为主，区域地质构造较为复杂，片理面极其发育。十房高速公路通省隧道以深埋长大成为该地区片岩公路隧道的控制性工程。隧道建设期间遇到大变形、纵向裂缝、钢拱架被剪断等问题，严重阻碍了隧道的正常建设。因此，研究片岩强度各向

异性特征及其机制十分必要。

片岩属典型的层状岩体，其变形有着明显的各向异性，这对工程岩体的稳定性会产生特殊的影 响[1

－4]

。王宏图等[5]对层状复合煤岩在三轴不等压应

力状态下的变形特性和强度特性进行了较为系统的试验研究；刘卡丁等[6]提出了层状岩体抗剪强度参数的经验表达式，并通过解析法分析了层面与外荷载相对方位对剪切破坏面方位的影响；张玉军等[7

－8]

收稿日期：2013-06-16

基金项目：交通运输行业联合科技攻关项目（No. 2010-353-342-260）。

第一作者简介：王章琼，男，1984年生，博士研究生，主要从事岩土力学与滑坡地质灾害方面的研究。E-mail：wzqcug@http://www.wenkuxiazai.com