Anisotropic strength and deformation of irregular columnar jointed rock masses under triaxial stress  

三向应力下不规则柱状节理岩体各向异性强度及变形特性

作　　者：QUE Xiang-cheng ZHU Zhen-de NIU Zi-hao ZHU Shu 阙相成;朱珍德;牛子豪;朱姝

机构地区：[1]College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China [2]Powerchina Huadong Engineering Corporation Limited,Hangzhou 311122,China

出　　处：《Journal of Central South University》2025年第2期643-655,共13页中南大学学报(英文版)

基　　金：Projects(42307192,41831278)supported by the National Natural Science Foundation of China;Project(CKWV20231175/KY)supported by the CRSRI Open Research Program,China。

摘　　要：The special columnar jointed structure endows rocks with significant anisotropy,accurately grasping the strength and deformation properties of a columnar jointed rock mass(CJRM)under complex geological conditions is crucial for related engineering safety.Combined with the irregular jointed networks observed in the field,artificial irregular CJRM(ICJRM)samples with various inclination angles were prepared for triaxial tests.The results showed that the increase in confining pressure can enhance the ability of the ICJRM to resist deformation and failure,and reduce the deformation and strength anisotropic degrees.Considering the field stress situation,the engineering parts with an inclination angle of 30°−45°need to be taken seriously.Four typical failure modes were identified,and the sample with an inclination angle of 15°showed the same failure behavior as the field CJRM.Traditional and improved joint factor methods were used to establish empirical relationships for predicting the strength and deformation of CJRM under triaxial stress.Since the improved joint factor method can reflect the unique structure of CJRM,the predictive ability of the empirical relationship based on the improved method is better than that based on the traditional joint factor method.特殊柱体结构使柱状节理岩体各向异性显著,准确掌握其在复杂环境下变形及强度特征对工程安全至关重要。结合工程现场所表现的不规则节理网络特征,制备了具有不同倾角的不规则柱状节理岩体试样,并开展了三轴压缩试验。试验结果表明,围压的增加使试样抵抗变形和破坏的能力提升,而使柱状节理岩体的各向异性水平降低。考虑现场地应力环境,倾角为30°~45°的工程部位需格外注意。本研究还总结了不规则柱状节理岩体试样的四种典型破坏模式,倾角为15°的试样表现出与现场柱状节理岩体相同的破坏形态。随后,分别采用传统及修正节理系数方法建立了三轴应力条件下柱状节理岩体的变形及强度经验关系,将其用于预测不同围压下柱状节理岩体的弹性模量及破坏强度。由于修正节理系数法更能反映柱状节理岩体的结构特征,基于此方法的经验公式表现出的预测能力更佳。

关 键 词：irregular columnar jointed rock mass triaxial stress STRENGTH DEFORMATION anisotropic mechanical property empirical relation 

分 类 号：TU45[建筑科学—岩土工程]