基于有限元方法的裂隙岩体等效强度参数研究

 利用等效连续介质力学方法分析裂隙岩体中工程稳定性时，选择合理的裂隙岩体等效强度参数是取得可靠分析结论的前提。依据建立的裂隙岩体网格，结合岩石统计损伤模型和结构面损伤模型，通过有限元数值方法研究裂隙岩体加载中的渐进破坏过程，以及裂隙岩体等效抗压强度的尺寸效应和各向异性。分析结果表明，从岩块到岩体，岩体等效抗压强度很快降低至稳定幅度，岩体抗压强度的各向异性也不显著。最后，对10 m尺寸的岩体进行不同围压下抗压强度的数值分析，得到裂隙岩体的强度参数，并和Hoek-Brown经验准则进行对比。文中的分析方法对于工程裂隙岩体的宏观参数取值具有参考价值。

NUMERICAL DETERMINATION OF STRENGTH PARAMETERS OF FRACTURED ROCK MASSES USING FINITE ELEMENT METHOD

The equivalent strength parameters of fractured rock masses are prerequisite to stability analysis of geotechnical engineering projects constructed in fractured rock masses which are encountered frequently in west China. Based on generated mesh of fractured rock masses，combined with statistic damage constitutive model of intact rock and damage model of structural plane，progressive failure of fractured rock masses is studied using finite element method(FEM). Furthermore，scale effect and anisotropy of compressive strength of fractured rock masses are studied. Study results show that the strength decreases and tends towards stability rapidly from intact rock to fractured rock masses，and the anisotropy of strength of fractured rock masses is not significant. At last，based on numerical simulation conducted on 10 m scale rock masses under different confining pressures，the equivalent strength parameters of fractured rock masses are gained and the results are compared with Hoek-Brown criteria. The method developed is helpful for determination of strength parameters of fractured rock masses.