多组贯穿节理岩体的扩展遍布节理模型研究

Extended Ubiquitous Joint Model for Jointed Rock Mass with Several Superimposed Joint Sets

天然岩体中常含有多组密集的贯穿节理,它的存在极大地弱化岩体的力学性质,对围岩的稳定有着重要的影响。针对含多组密集节理岩体,将其看成等效均质的复合材料,建立了扩展遍布节理模型。岩体和节理均是弹性-理想塑性本构关系,都服从带抗拉强度的Mo-hr-Coulomb屈服准则。提出了屈服类型判断方法,并成功推广用于多组节理屈服类型判断,为选择哪种塑性势函数进行应力修正提供理论依据。采用C++语言,基于VStudio2005开发平台,将该模型成功嵌入到FLAC3D软件中,并通过两组节理岩体的单轴压缩试验和三轴压缩试验验证了模型的正确性。

Natural rock mass usually contains multiple superimposed joint sets, which greatly weaken the me- chanical behavior of the rock mass and remarkably impact the stability of surrounding rock mass. An extended ubiqui- tous joint model has been established for the rock mass with several sets of joint weak-planes, which is considered as a macroscopic composite material in a broader sense. Both rock mass and joint weak-planes are elastic-ideal plastic model. The criterion for failure on the joint weak-plane consists of a composite Mohr-Coulomb envelope with tension cutoff, and the rock mass satisfies the failure criterion which is the same as the joint weak-plane. This method is pro- posed for judging yield type and is utilized in rock mass with sets of superimposed joints. It provides a theoretical ba- sis on choosing the type of plastic potential function for stress corrections. Then, the proposed model has been suc- cessfully established and embedded in FLAC3D on the basis of the VStudio2005 developing platform of constitutive model. It is verified by simulating the uniaxial compression test and triaxial compression test on rock mass including two joint sets. The calculated results show that this model is correct.