中文摘要：

在普立特大桥隧道锚现场模型试验的基础上,采用数值模拟技术揭示了隧道锚围岩变形破坏过程：围岩破坏面从锚体底部与围岩接触面附近启裂,并逐渐向外呈圆台状扩散,破坏形式为拉剪破坏。并且,锚体前部临空岩体被拱出而发生拉破坏。破坏面上的应力分布随着拉拔荷载增大而发生复杂变化。基于此,通过在破坏面上建立力的平衡关系,提出了隧道锚围岩抗拔力计算模式。该计算模式与现有文献不同,体现了夹持效应以及破坏面上的复杂应力变化。破坏面上的应力分布需要通过模型试验和数值模拟论证得到。今后,在针对不同强度、不同结构特征的岩体进行全面试验分析的基础上,可以对破坏面形态和应力大小进行取值建议。采用该模式验证了试验结果,估算得到大桥原型锚碇的极限抗拔力非常大。目前隧道锚设计普遍偏于保守,隧道锚在中、软岩中仍然可以使用。讨论了破坏面形态特征可能的变化、岩体结构特征对抗拔力的影响等问题。

英文摘要：

Based on the field model tests of tunnel-type anchorage in the Pulite bridge, the deformation and failure process of rocks surrounding tunnel-type anchorage are revealed via numerical simulation. The failure surfaces in the surrounding rocks initiate around the rear interfaces between the plugs and rocks, and propagate outward with a frustum shape. The failure mode is tensile-shear. Moreover, the rocks near the free surfaces in the front of the plugs are pushed outward and damage with tensile mode. The stresses vary complicatedly as the pullout force increases. Based on these, a computational mode of the pullout force for the surrounding rocks is proposed by establishing the equilibrium relationship of forces acting on the failure surfaces. Different from the published literatures, this mode embodies the ＂clamping effect＂, and reveals the complicated variation of forces on the failure surfaces as well. It is necessary to execute field tests and numerical simulations in order to assess the values of the forces on the failure surfaces. In future, the possible shapes of the failure surfaces and the variation ranges of forces on the failure surfaces can be suggested after the accumulated studies for various rocks with different strengths and structures. The computational mode is verified by the testing results, and is used to estimate the pullout force of the prototype anchorage. The results show that the ultimate pullout capacity is very large. The design philosophy of the tunnel-type anchorages is considerably conservative nowadays. We believe that it is probable to apply the tunnel-type anchorages in moderate-strength and even soft rocks. The issues concerning the changes of failure surfaces in different rocks, the influence of rock structures on the pullout capacity, etc., are discussed.