基于Hoek-Brown强度准则深埋隧道掌子面稳定性分析

Stability analysis of deep-buried tunnel face based on Hoek-Brown strength criterion

为了研究孔隙水压力作用下深埋隧道掌子面的稳定性,构建了深埋盾构隧道的二维刚性有限平动多块体的破坏模式,并引入了Hoek-Brown强度准则。利用极限分析得到掌子面前方土体的内部耗散能和外力做的功,利用Hoek-Brown强度准则推导得到极限支护力的目标函数,通过MATLAB数值软件的规划求解得到支护力的解,和既有文献中的成果对比,2种方法得到解的最大误差为6.7%,验证了Hoek-Brown强度准则的有效性。对各个岩体参数下深埋隧道掌子面极限支护力的变化规律进行分析,结果表明:深埋隧道掌子面前方的极限支护力随着扰动因子D和孔隙水压力系数ru的增大而增大,随着地质强度指标GSI和参数mi的增大而减小;破坏范围随着参数mi和孔隙水压力系数ru的增大而减小,而随着地质强度指标GSI和扰动因子D的增大而增大。研究结果可为岩质地层中深埋盾构隧道掌子面支护力的设计提供理论依据。

In order to investigate the stability of deep tunnel face witn the pore water pressure,a two-dimensional rigid finite translational multi block failure mode of deep shield tunnel was constructed,and the Hoek Brown strength criterion was introduced.The internal dissipative energy and the work done by the external force of the soil in front of the tunnel were obtained by using the limit analysis,and the objective function of the limit support force was derived by using the Hoek-Brown strength criterion.The solution of support force was obtained by using the MATLAB numerical software,and it was compared with the achievement in the existing literature.The maximum error between the solutions obtained by two methods was 6.7%,which verified the effectiveness of the Hoek-Brown strength criterion.The variation laws of the limit support force of deep-buried tunnel face under various rock mass parameters were analyzed,and the results showed that the limit support force in front of the deep-buried tunnel face increased with the increase of the disturbance factor D and the pore water pressure coefficient ru,and decreased with the increase of the geological strength index GSI and the parameter mi.The failure range decreased with the increase of the parameter mi and the pore water pressure coefficient ru,and increased with the increase of the geological strength index GSI and the disturbance factor D.The results can provide theoretical basis for the design of support force on the deep-buried shield tunnel face in the rock stratum.