基于广义Hoek-Brown准则强度折减法的岩坡稳定性分析

Stability analysis of rock slope by strength reduction method based on generalized Hoek-Brown failure criterion

针对岩质高边坡的稳定性分析问题,开展了基于广义Hoek-Brown破坏准则强度折减法的研究。提出了判别强度折减法合理性的两个基本标准:与Mohr-Coulomb准则强度折减法的一致性和能否体现节理岩体的真实破坏特征。基于以上标准,对比了3种不同的基于广义Hoek-Brown破坏准则的强度折减方法:σci、mi,σci、GSI和mi、GSI均同比折减,理论分析表明:mi、GSI同比折减更符合前述标准。最后,通过对工程实例的对比研究,验证了这一结论,并提出mi、GSI同比折减更能体现节理岩体的真实破坏特征,因而其安全系数的计算结果也更加真实可靠。

The strength reduction method based on the generalized Hoek-Brown failure criterion is studied.Two basic standards judging the rationality of the strength reduction method are proposed as follows:it coincides with strength reduction method based on the Mohr-Coulomb criterion and represents the real failure characteristics of jointed rock.Based on the two standards,three kinds of strength reduction methods are contrasted by reducingσci and mi,σci and GSI,and mi and GSI with the same factor.Analysis results indicate that the method of reducing mi and GSI with the same factor is more reasonable.Through comparative study of one engineering case,the method of reducing mi and GSI with the same factor can represent real failure characteristic of fractured rock is proved;and then more reliable safety factor during the stability analysis of rock slope is obtained.