拉力型锚索极限承载力的解析解与试验研究

Analytical solution and experimental study on ultimate bearing capacity of tensile type anchor cable

针对拉力型锚索锚固岩体的破坏形式,结合拉力型锚索作用下岩体破坏面方程,采用Mohr-Coulomb强度准则,对破坏区岩体的极限平衡状态进行研究。以此为基础,推导基于岩体破坏面方程的拉力型锚索极限承载力的解析解,并分析破坏面形状与锚索几何参数对极限承载力的影响,与拉力型锚索的试验成果进行对比分析。研究结果表明:采用拉力型锚索的解析表达式可以较合理地估算拉力型锚索的极限承载力;基于围岩体破坏的锚索承载力与其破坏面形状有关,对于锚固段存在结构面或滑动面的锚索,需对锚索基于围岩体破坏的承载力进行验算。

Focused on the failure modes of anchored rock mass, combined with researches of failure surface equation of anchored rock mass, limit equilibrium state of rock mass in failure zone was studied by adopting Mohr-Coulomb strength criterion. Based on the obtained equation of failure surface, analytic solution of ultimate bearing capacity of tensile anchor cable was deduced. The influences of failure surface shape and geometry parameters of cable on the ultimate bearing capacity were analyzed. The analytical solution of a tensile type cable was compared with the experimental results. The results show that the ultimate bearing capacity of tensile cable can be estimated well by the analytical expression established in this paper. Since surrounding rock failure surface shape is related to rock mass ultimate bearing capacity, the ultimate bearing capacity of surrounding rock with structure planes and sliding surfaces in anchorage sections should be calculated.