基于脆剪分析的岩体非线性强度特性在统一强度理论中的实现

Realization of rock mass nonlinear strength characteristics in unified strength theory based on brittle-shear strength analysis

针对统一强度理论(UST)拟合非线性强度的局限和岩土材料强度特点,提出拟合岩土非线性强度特征的脆性剪切分析方法,建立了过渡式双线性强度分解公式。以脆断、剪切双重破坏机制,解释Hoek-Brown准则的非线性特征机制,并推导出体现岩石、岩体类材料非线性强度特征的脆剪强度公式。Mine-by隧道和北山花岗岩强度数据分析显示,在岩体折减强度、试验数据直接拟合实例分析中,脆剪强度与Hoek-Brown强度相关性系数均在0.98以上,在该基础上建立岩体非线性强度脆剪分析的双线性过渡式,并提出对应的统一强度理论形式,实现统一强度理论在拟合岩土非线性强度准则中的扩展。

Considering the limitation of the unified strength theory (UST) in nonlinear fitting and nonlinear features of geotechnical materials, a brittle-shear strength analysis method is proposed; and a transition bilinear formula is derived. Nonlinear strength feature of Hoek-Brown criterion is explained based on the double failure mechanism of fracture and shear; and an associated formula with highly correlation is obtained. Mine-by tunnel and the strength of Beishan granite data results analysis show that coefficients of correlation of Hoek-Brown rock mass strength, experimental data and brittle-shear strength values are all above 0.98. Twin formulas of Hoek-Brown criterion in the form of UST are derived based on the brittle-shear nonlinear fitting. Application of UST to fitting nonlinear strength of geotechnical materials is realized.