为了提高Hoek-Brown准则对层状岩的适用性，减少对层状岩地质强度指标（GSI）取值的主观性，提出了考虑层状岩石GSI值随层理倾角β 变化的修正Hoek-Brown屈服准则。首先收集不同层理角的层状岩在不同围压下的三轴试验数据，结果显示，层状岩石峰值强度与层理角β 呈U形曲线关系。然后定义层理倾角β = 0º的岩样为完整岩石，采用Hoek-Brown准则得到完整岩石的单轴抗压强度σc与参数mi，以此反算其他层理倾角下对应的GSI值。基于GSI 随层理倾角β 的变化趋势，采用高斯函数对GSI与β 的变化关系进行拟合，从而建立基于Hoek-Brown准则的含层理岩石强度模型。最后对比GSI弱化模型所得峰值强度，验证了提出的修正Hoek-Brown准则对预测不同倾角与围压下层状岩强度具有较好的适用性，并对屈服准则中引入的新参数的意义进行了讨论。 In order to improve the applicability ofHoek-Brown failure criterion and reduce subjectivity in the determination ofgeological strength index (GSI) value for anisotropic rocks

a modifiedHoek-Brown failure criterion is proposed

whichconsiders the variation of the GSI value with the bedding angle of anisotropicrocks. Triaxial compression test data of anisotropic rocks with differentbedding angles were first collected. The results show that the peak strength ofanisotropic rocks exhibits a U-shaped relation with bedding angle β. Then

the rock specimen with thebedding angle β = 0º is defined as the intact rock. The uniaxial compressive strength σc and material parameter mi of intact rocks are obtained from data fitting using Hoek-Brown failurecriterion. The corresponding GSI values under different bedding angles arecalculated. The relationship between GSI and bedding angle β is fitted using Gaussian function

and anew strength model of anisotropic rocks is established based on Hoek-Brownfailure criterion. Finally

the proposed model is verified by comparing thepeak strength obtained from the GSI-softening model. It is found that themodified Hoek-Brown failure criterion is suitable for predicting the strengthof anisotropic rocks with different bedding angles and under various confiningpressure. The physical meaning of the new parameters in the model is alsodiscussed.