中文摘要：

影响深埋圆形硐室围岩塑性区扩展的因素众多，选取黏聚力、内摩擦角、变形模量、容重、初始地应力、硐室半径6种主要敏感因素，采用灰色关联分析方法探讨各因素与塑性区扩展半径的关联情况。以某大型水电站2＃压力管道下平段为例，通过无量纲化处理、极差变化等，得到了以各敏感因素为子序列矩阵、塑性区扩展半径为母序列矩阵的对应序列矩阵，建立了以灰色关联度为评价结果的敏感因素分析灰色关联模型。计算得到围岩塑性区扩展半径敏感因素排序结果为内摩擦角＞初始地应力＞黏聚力＞硐室半径＞变形模量＞容重，即塑性区扩展半径受内摩擦角、初始地应力影响最为显著，而受围岩变形模量、容重影响最小。

英文摘要：

Considering plenty varieties of effect factors to the plastic zone extension of the surrounding rocks in the deep-buried circular tunnel,we chose the cohesive,internal frictional angle,deformation modulus,unit weight,initial ground stress and the chamber tunnel radius as the son fac-tors based on the internal and external causes of the plastic zone extension,used the grey relational analysis method to study the relationship be-tween the son factors and the plastic zone extension radius. Taking a large-scale hydropower pressure pipe level segment 2#as an example,the cor-responding sequences model composing the sensitive factors （son sequence）and the plastic zone extension radius （mother sequence）could be built by the deal with dimensionless and the range change. It obtained the following ordering of the sensitive factors through grey relational analysis：in-ternal frictional angle ＆gt; initial ground stress ＆gt; cohesive ＆gt; chamber radius ＆gt; deformation modulus ＆gt; unit weight. It implied that the influences of internal friction angle and initial ground stress were the most prominent,and in the opposite the sensitivity of deformation modulus and unit weight was the lowest.