黄土地区隧道锁脚锚管作用机理分析研究

Mechanism analysis for locking pin of anchor pipe of tunnel construction in loess area

锁脚锚管在隧道施工中被广泛应用,而目前施工中锁脚锚管的长度、下插锚角度等几乎全部依靠工程经验来确定。通过有限元软件模拟了黄土隧道锁脚锚管在不同长度和角度下承担的最大内力和最大变形量,对比分析了锁脚锚管的长度、锚管下插角度与位移的关系。研究结果表明,锚管长度越长,变形越小,但最为经济的锚管长度为3 m左右;当所加锚管下插角在±30°时有利于支护内力的发挥。在研究结论基础上提出了隧道施工中应该采用的锁脚锚管合理长度及下插角度。

The locking pin of anchor pipe is widely used in tunnel construction in loess area,while the length and the insertion angle,etc are mostly determined by engineering experience.The finite element software was applied to simulate the maximum internal force and deformation under different lengths and insertion angles,and the relationship among the locking pin length,insertion angle and the displacement were obtained.The results showed that the longer the locking pin was,the smaller the deformation was;the most economical length is 3 m;the insertion angle of±30°was the most favorable to forming supporting function.Therefore,the reasonable length and insertion angle of locking pin in tunnel construction in loess area were proposed.