As for one running section of Hefei Metro Line 1 adjacent to a pile group foundation, the shield driving process is simulated using the finite-element software Midas, with a focus on segment deformation and internal force change. The tunneling process of a shield machine under different grouting pressures and approaching or not approaching a pile group is simulated and a comparative analysis of the effect on the segment's internal force and deformation is conducted. The results show that:when grouting pressure is within the range of 0.1 MPa to 0.4 MPa, the internal force and deformation of the tunnel segment increase with an increase of the grouting pressure during shield tunnelling;and the internal force and deformation of the tunnel segment are restrained by piles during shield tunnelling adjacent to a pile group foundation, and these are related to the distance between the tunnel segment and the piles, with apparent restraint of the horizontal displacement for the tunnel segment closest to the pile group foundation.%基于合肥地铁1号线某区间段盾构隧道施工近接群桩基础工况,文章通过Midas软件模拟盾构掘进过程,着重关注管片的变形和内力变化情况,同时模拟不同注浆压力大小或隧道是否近接群桩状态下的盾构掘进过程,对其计算结果中隧道管片的内力及变形的影响程度进行对比分析.结果表明:注浆压力在0.1~0.4 MPa范围内,随着注浆压力的增加盾构隧道掘进过程中管片的内力与变形均增大;盾构隧道在近接群桩的施工中,管片的内力与变形均受到了群桩的抑制作用,且与管片距离桩基远近相关,其中距离桩基最近位置处的管片水平位移的抑制现象更为明显.计算结果能为其他类似近接施工中研究隧道管片的内力与变形特性提供参考.
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