岩土力学2017，Vol.38Issue(3)：810-820,11.DOI:10.16285/j.rsm.2017.03.025
隧道锚围岩抗拔机制及抗拔力计算模式初步研究
Preliminary study of pullout mechanisms and computational mode of pullout force for rocks surrounding tunnel-type anchorage
摘要
Abstract
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.关键词
隧道锚/现场模型试验/抗拔机制/抗拔力计算公式/破坏面/夹持效应Key words
tunnel-type anchorage/field model test/pullout mechanism/computational mode of pullout force/failure surface/clamping effect分类
建筑与水利引用本文复制引用
张奇华,李玉婕,余美万,罗荣,邬爱清..隧道锚围岩抗拔机制及抗拔力计算模式初步研究[J].岩土力学,2017,38(3):810-820,11.基金项目
国家自然科学基金青年基金(No.51409013) （No.51409013）
国家自然科学基金面上项目(No.51579016).This work was supported by the Young Foundation of National Natural Science Foundation of China (51409013) and the General Program of National Natural Science Foundation of China (51579016). （No.51579016）
