Hoek-Brown强度准则在岩石及岩体工程中得到了广泛的应用,而目前基于该准则建立起的弹塑性本构模型在理论上还存在着一些不足;考虑到不同围压条件下的岩石材料塑性形变发展特征,提出了基于分段隐式修正塑性势的塑性流动法则,解决了其它基于广义H-B准则所建立的本构模型中塑性流动方向不连续及需额外引入参数等问题;采用基于误差控制的改进欧拉中点积分算法,对该本构模型进行了数值实现并给出了单积分点层次的结果验证;进一步将成果嵌入到了同济曙光岩土工程三维数值平台(Geo FBA3D)当中,并给出了一类经典弹塑性力学问题的计算结果验证以及其在隧道工程中的典型应用算例。
Hoek-Brown criterion has been widely applied in rock engineering. However, there still exists a defect in the elastoplastic rock constitutive model proposed on the basis of this criterion. A plastic flow rule based on a piecewise implicitly modified plastic potential is proposed here when the feature of the plastic deformation development of rock under different confining pressure is considered. This method can solve the plastic flow discontinuity problem in other constitutive model using generalized H-B criterion and avoid the additional input parameters as well. Based on the modified Euler mid-point type constitutive integration method, the numerical implementation of this model has been conducted, with the result verification on single integration point level. This model has also been attached to the numerical platform of Geo FBA3 D, and further results verification in a classical elastoplastic mechanics problem as well as a typical application example in tunnel engineering are also developed.