(1.北京科技大学 应用科学学院，北京 100083；
2.中国科学院 地质与地球物理研究所，北京 100029；
3.上海隧道施工技术研究所，上海 200233)
摘 要: 用类岩石材料白水泥多裂纹模型进行了双向加压实验。实验结果表明，在各种侧压σ2下，宏观强度σc1基本上随α增加而变大，但在α=45°左右呈现最低值；随着侧压σ2增加，宏观强度σc1明显提高。用εθmax及σθmax断裂判据对单个裂纹进行了分析，所给出的初始开裂角理论值与该多裂纹模型实验值非常相符，对初始开裂载荷，能给出多裂纹模型实验值的上限。以单向加压实验结果为基础，建立了便于工程应用且适用于多裂纹体的等效正交各向异性本构关系。由此本构关系所得的计算结果与双向加压实验结果符合良好。
关键字: 双向加压；多裂纹体；正交各向异性；本构关系
and orthotropic constitutive
relationship for regular cracks
in replicated rock mass
（1.School of Application Science,
University of Science and Technology Beijing，
Beijing 100083, China；
2.Institute of Geology and Geophysics，
Chinese Academy of Sciences，Beijing 100029, China;
3.Shanghai Institute of Tunnel，Shanghai 200233, China）
Abstract:A series of biaxial compression experiments，dealing with the effects of regular cracks in replicated rock mass，have been carried out. The results show that the macro-strength σc1 increases basically with the increasing inclined angle α of crack and remarkably with the increaseing side compression σ2.But when α≈45°，σc1 be comes the lowest. The initiation angle θ of the cracks and the up limit of the critical fracture load can be estimated well by the mixed-mode fracture criterions of εθmax and σθmax.Based on the results of uniaxial compression experiments，anorthotropic constitutive relationship is constructed，which can be applicable to the multi-cracked body problem of mining and other underground engineering.The computed re sults by this relationship agree well with the biaxial compression experime nt results.
Key words: biaxial compression; model experiment; multi- cracked body; orthotropy; constitutive relationship
