Bandis经验公式修正及其应用

针对三维离散元程序中刚度参数合理选取方法及其应用开展研究.通过理论分析，给出了结构面剪切刚度及法向刚度的理论公式；结合室内剪切试验研究和数值分析，得到了符合工程实际的剪切刚度修正Bandis经验公式及法向刚度参数经验公式，从而明确提出了一种结构面刚度参数的选取方法；通过实际工程边坡稳定性分析，探究了基于上述方法选取的参数对实际工程模拟的适用性.研究表明，岩体结构面刚度参数是应力的函数，修正Bandis经验公式能够较为完善地表征剪切破坏前结构面的剪切刚度变化规律；利用编制FISH程序使刚度参数随应力变化而改变的方法，使3DEC软件对工程岩体变形特征的模拟更加符合实际，从而验证了该方法的合理性.

Correction and application of the Bandis empirical formula

A reasonable method was discussed for choosing and applying stiffness parameters in a 3D distinct element code. The formulas of pre-peak shear stiffness and normal stiffness of the fracture were derived through theoretical analysis. In combination with data from indoor shearing experiment,a corrected Bandis empirical formula of shear stiffness and a normal stiffness empirical formula were developed,which were proved to be logical by numerical analytical study. At last,a reality engineering of slope slide was discussed as a further evidence to describe the applicability of stiffness parameters chosen by the method mentioned above. It is obvious that the stiffness parameters of the fracture are a function of stress whether shear stiffness or normal stiffness. The corrected Bandis empirical formula can reflect the behavior of shear stiffness in the pre-peak range well. It is practicable to make the stiffness of the fracture changed with stress by developing a FISH program(in 3DEC),and therefore,the simulation can more in line with the practical engineering. In conclusion,the method mentioned above is proved to be reasonable.