基于统计岩体力学的隧道围岩分级方法  

A Tunnel Surrounding Rock Masses Classification Method Based on Statistic Mechanics of Rock Masses

作　　者：郗鹏程 伍法权[1,2,3] 包含 

机构地区：[1]中国科学院地质与地球物理研究所中国科学院页岩气与地质工程重点实验室,北京100029 [2]中国科学院地球科学研究院,北京100029 [3]中国科学院大学,北京100029

出　　处：《地下空间与工程学报》2018年第1期131-137,共7页Chinese Journal of Underground Space and Engineering

基　　金：中国科学院重点部署项目(KZZD-EW-05)

摘　　要：国标《工程岩体分级标准》(GB50218—94)在隧道设计阶段应用广泛,但是由于地质条件的复杂性及岩体各向异性的影响,不能精准预测施工阶段隧道围岩等级。本文基于统计岩体力学提出了针对隧道施工阶段的围岩分级方法,即通过现场岩体结构面统计和岩石力学试验,获取结构面参数和岩石力学参数,应用统计岩体力学强度理论及本构理论,获得具有各向异性特征的岩体弹性模量参数E_m,进而应用经验公式换算得到BQ值,从而确定隧道围岩基本分级。在实例中,小盘岭2号隧道GDK347+360里程处围岩设计分级为Ⅲ级;应用此方法重新分级的结果为Ⅳ级,低于设计分级,这与现场观察和监测的围岩性状吻合,说明本方法在隧道施工阶段能较为客观地反映围岩性质。以上研究结果表明,在含碳泥质板岩隧道围岩施工阶段岩体分级过程中,本方法具有良好地适用性。It was known that Standard of Engineering Classification of Rock Masses（ GB50218—94）,＂national standard＂for short herein,is used widely in tunnel design stage. But it couldn＇t predict the surrounding rock mass classification level in construction phase because of the complex geological conditions and rock mass anisotropy.Therefore,based on the principles of statistical mechanics of rock masses（ SMRM for short）,a rock mass classification applied in the tunnel construction phase is proposed. First,a series of statistics analysis are performed after calculating the data of discontinuities of surrounding rock masses,and rock strength parameter is got from rock mechanical test. Then,the elastic modulus of surrounding rock mass with anisotropy property could be got by using the strength theory and constitutive theory of statistic mechanics of rock masses. On the basis of previous studies,it is possible to convert Emto BQ by empirical formula,which means that the tunnel surrounding rock masses＇ grade is determined naturally. For example,Xiaopanling 2 # tunnel,the computed surrounding rock mass level is Ⅳ,compares to Ⅲ of the design level. To sum up,SMRM rock mass classification method fully reflects the fact that anisotropy of argillaceous slate with carbon has a great influence on the rock mass classification in tunnel excavation stage,and this method has strong applicability and wide serviceability in this situation.

关 键 词：围岩分级 BQ 弹性模量 统计岩体力学 各向异性 

分 类 号：P642.3[天文地球—工程地质学]