以郑西铁路客运专线函谷关隧道工程为依托，通过理论分析和现场1︰1原型试验相结合，综合分析确定高速铁路大断面深埋黄土隧道围岩内变形模式以及基于此变形模式的锚杆作用机理和作用效果。研究结果表明：拱顶部围岩内位移衰减缓慢，不同深度处围岩相对位移值很小，出现整体下沉现象；边墙部围岩位移衰减较快，不同距离处围岩相对位移值较大；围岩内不同部位变形模式是影响锚杆受力的关键性因素，拱部锚杆受力很小，边墙锚杆受力较大；建议隧道拱部130°范围内可不设置锚杆，该范围以下至墙角设置全长粘结型系统锚杆。研究结果有效地指导了现场设计与施工，同时也为类似工程提供参考依据。

Taking Hanguguan tunnel on ZhengzhouXi'an passengerdedicated railway as an example, the authors synthetically analyze and determine the deformation model of the surrounding ground of deepburied large crosssection tunnels in loess stratum, as well as the working mechanisms of the bolts of these tunnels based on the deformation model, by theoretic analysis and insitu prototype test. The study results are as follows: For the surrounding ground at the arch, the attenuation of the displacement is slow, the relative displacement of the surrounding ground at different depths is very small and integral settlement occurs; For the surrounding ground at the sidewall, the attenuation of the displacement is rapid and the relative displacement of the surrounding ground at different distances is large; the deformation model of the surrounding ground at different positions is the key factor that influences the working mechanisms of the bolts and the force that the bolts at the arch undertake is very small, while the force that the bolts on the sidewall undertake is large. Based on the study results, the authors suggest that bolts may not be installed in the 130° range of the tunnel arch and that fullybonded bolts should be installed within the scope from the mentioned range to the side wall foot. These study results, which have provided effective guidance for the design and construction of the tunnel, can be used as reference for similar works in the future.