Abstract: Three-dimensional numerical analysis on tunnel excavation was carried out by the finite element software ABAQUS.From the point of view of stress and strain，the definition scope of deep-shallow-buried soil tunnel was studied.The research results show that in the process of tunnel construction，the displacement value of the C point of the vault is the largest，and it has the trend of gradual increase with the increase of the depth of the burial.When the buried depth of the tunnel is increased to a certain critical state，the C point displacement of the vault does not change significantly with the increase of the depth of the burial，but tends to a fixed value.The stress release law of tunnel is the same as its vertical displacement rule.The vertical stress of the C point of the tunnel vault is increased with the increase of the tunnel burial depth，and the change curve of stress also tends to be gentle.The vertical stress of the C point has a good agreement with the calculation value of Terzaghi theory.Based on the above，the critical burial depth value for deep-shallow-buried tunnels was determined by means of theoretical analysis; and the proposed value was further verified by the current specification and Terzaghi theory.

Key words: tunnel engineering, dividing line for deep-shallow-buried tunnels, shallow-buried tunnels, deformation, numerical simulation

摘要： 基于有限元软件ABAQUS进行隧道开挖过程的三维数值分析，从应力、应变的角度出发，对土体隧道深浅埋的界定范围进行了研究，研究结果表明： 隧道施工过程中，拱顶C点的位移值最大，并且随着埋深的增加而具有不断增大的趋势；当隧道埋深增加到某一临界状态以上时，拱顶C点位移不再随着埋 深的增加而显著变化，而是趋于一个定值；隧道的应力释放规律和其竖向位移规律相同，隧道拱顶C点的竖向应力随着隧道埋深的增大，应力变化曲线也 趋于平缓，且C点的竖向应力与太沙基理论计算值较为吻合。在此基础上，结合理论分析的手段确定隧道深浅埋的界限埋深值，并运用现行规范和太沙基 理论对此界限埋深值进行了进一步的验证。

关键词: 隧道工程, 界限埋深, 浅埋隧道, 变形量, 数值分析