强度折减法在Hoek-Brown准则中的应用

Application of strength reduction method in Hoek-Brown criterion

为了在Hoek-Brown准则中实施强度折减法,并使其得到的结果与Mohr-Coulomb准则中强度折减法得到的结果等效,首先,通过理论推导确定Hoek-Brown准则参数m,s,σci与粘结力c和内摩擦角φ之间的关系;然后,进一步得到在Hoek-Brown准则中实施强度折减法时,m,s和σci的折减系数以及它们之间的关系;最后,由FLAC3D软件建立计算模型,采用所确定的折减方法计算边坡的安全系数,并将该结果与Mohr-Coulomb准则得到的结果进行对比,结果表明:参数m,s和σci的折减系数须满足一定关系,强度折减法在Hoek-Brown准则和Mohr-Coulomb准则中得到的安全系数的差别为3.54%,差别微小,从而验证了所确定的折减方法的可靠性。

In order to implement the strength reduction method in the Hoek-Brown criterion, and make the result obtained by Hock-Brown criterion equivalent to that by Mohr-Coulomb criterion, some deductions and numerical calculations were done. Firstly, the relationships among Hoek-Brown parameters m, s, σci and cohesion c, internal friction angle were established by theory deduction. Secondly, the reduction factors of m, s, σci, were obtained by further theory deduction and their relationships among these factors were found. At last the calculation models were obtained by FLAC^3D software. In the calculation procedure for safety factor of slope, the proposed reduction method was adopted. The comparative analysis was done for the safety factors obtained by Hoek-Brown and Mohr-Coulomb criterion. The result shows that, three reduction factors for m, s and σci should satisfy certain relationship, the difference between the two safety factors is 3.54%, which is very small, which proves that the reduction method proposed is correct.