横观各向同性岩体平直−光滑节理双模型细观参数联合标定方法

A transversely isotropic rocks integrated microparameter calibration method for flat joint model and smooth joint model

为更真实地模拟节理岩体的力学行为,颗粒流程序(PFC)采用平直节理模型(FJM)和光滑节理模型(SJM)分别模拟横观各向同性岩体的岩石部分和节理部分。但双模型(FJM和SJM)标定涉及的细观参数多,导致宏观−细观参数对应关系复杂。为此,本文提出一种横观各向同性岩体双模型细观参数联合标定方法。首先,遴选核心细观参数,建立岩体参数标定指标体系,对指标体系中的宏观−细观参数进行了敏感性分析,得到显著影响各宏观参数的细观参数;然后,提出FJM和SJM细观参数标定优先级体系,构建双模型细观参数联合分析方法,建立表征宏细观参数之间的函数关系;第三,为提高参数标定的准确性,提出了细观参数迭代校准方法;最后,形成了一套针对横观各向同性岩体的标准化细观参数标定流程。研究结果表明:所提标定方法可应用于页岩的细观参数标定,标定结果的相对误差小于3%,验证了该方法的有效性。

In order to simulate the mechanical behavior of the jointed rock mass more realistically in particle flow code(PFC),the flat joint model(FJM)and smooth joint model(SJM)were used to simulate the rock part and the joint part of the transversely isotropic rock mass,respectively.However,there exists complex relationship between macroscopic and microscopic parameters due to a large number of microparameters of dual-model.Aiming at addressing this challenge,an integrated parameter calibration method of dual-model was developed.Firstly,a calibration parameter index system was proposed through parameter selection.Numerical simulations and sensitivity analysis were conducted to obtain the relationship between macroparameters and microparameters.Secondly,microparameters priority of FJM and SJM was carried out,which provided an integrated analysis way of dual-model microparameters.The macroscopic and microscopic parameter functional representation system was developed.Thirdly,in order to improve the accuracy of parameter calibration,an iterative calibration method for microparameters was proposed.Finally,a set of standardized microparameter calibration procedures for transversely isotropic rocks was proposed.The results show that the calibration method can be applied to the integrated microparameter calibration of shale,and the relative error of calibration results is less than 3%,which verifies the effectiveness of this method.