摘要：本文针对均质各向同性条件下岩基承载力特征值的解法，考虑岩体各向异性影响修正或改进来确定岩基承载力特征值。岩体的各向异性系数，可根据岩体的横波速与纵波速之比，根据不同的岩体情况确定，岩体的各向异性系数是横波速与纵波速之比的n次方，本文研究n=0～3，不同的计算方法n值取值不同。通过计算分析比较，岩体完整性越好，四种方法确定的承载力特征值越接近，岩体完整性越差，抗剪强度参数法解、Hoek-Brown强度准则法解计算值较工程地质勘察经驗公式法和建筑地基基础经验公式法计算值总体偏小。四种方法确定的岩基承载力特征值均可作为地质建议值。

Abstract： Aimed at the solution of bearing capacity characteristic value in the homogeneous isotropic conditions， this paper considers the anisotropy effect correction of the rock mass to determine or improve the batholith bearing capacity characteristic value. The anisotropy coefficient of rock mass can be determined by the ratio of transverse wave velocity and longitudinal wave velocity of the rock mass and the different rock mass conditions. The anisotropy coefficient of rock mass is nth-power of the ratio of transverse wave velocity and longitudinal wave velocity. This paper studies n=0～3， the values of n are different for the different calculation methods. Through the calculation analysis and comparison， the better the rock mass integrity， the closer the bearing capacity characteristic values determined by the four methods. If the rock mass integrity is worse， the calculated values of the calculation method of shear strength parameters and calculation method of Hoek Brown strength criterion will smaller than those of the engineering geological survey and empirical formula method and building foundation empirical formula method. The batholith bearing capacity characteristic value determined by the four methods can be as geological recommended values.

关键词：岩基承载力特征值；各向异性系数；岩块单轴饱和抗压强度标准值

Key words： batholith characteristic value of the bearing capacity；anisotropy coefficient；rock standard value of saturated uniaxial compressive strength

中图分类号：TU473.1 文献标识码：A 文章编号：1006-4311（2016）07-0208-03

1 绪言

岩基承载力特征值严重受岩体各向异性影响，岩体各向异性影响主要受岩体所处温度、应力状态，岩体结构面的发育程度，岩体内地下水的发育程度和规模，岩体的水理性等因素控制。研究发现，根据波动理论，岩体的各向异性影响系数可用岩体的横波速和纵波速之比来反映，根据不同的岩体情况，根据岩体的横波速与纵波速之比采用不同的各向异性系数，各向异性系数是波速比的n次方，本文研究n=0～3。

2 未考虑各向异性影响岩基承载力特征值的确定方法

根据三轴压缩原理、广义Hoek-Brown强度准则及格里菲斯强度理论，基于均质各向同性岩体之岩基承载力特征值的确定公式[1]：