盾构隧道施工对邻近建筑物差异沉降与扭曲变形影响分析∗

针对盾构隧道施工侧穿既有建筑物问题，结合南京地铁一号线北延段工程，以盾构隧道侧穿某浅基础建筑物为研究对象，通过对建筑物沉降实测数据进行分析，并利用Plaxis 3D 软件建立数值模型，研究了隧道距建筑物不同水平距离和盾构以不同角度穿越对建筑物差异沉降与扭曲变形特征的影响。结果表明：随着盾构开挖面逐渐接近建筑物，建筑物差异沉降及扭曲变形逐渐增大；差异沉降量在盾构机通过时达到最大值，之后趋于稳定，而扭曲变形峰值出现在盾构开挖面到达建筑物中点截面位置时，随后逐渐减小；当建筑物中心至隧道轴线的水平距离与隧道外径之比L/D=0.5~2 时，建筑物差异沉降量较大，在L/D=1.5 时达到峰值；当盾构穿越夹角从θ=0°增大至θ=90°时，建筑物最大差异沉降量不断增加，而最终扭曲变形值则先增大后减小，在θ=45°时扭曲变形达到峰值。研究结果可为盾构隧道侧穿浅基础建筑物时相关类似工程提供参考。

Impact of Shield Tunnel Construction on Differential Settlement and Twist Deformation of Adjacent Buildings

This study investigated the response of existing buildings to the side-crossing of shield tunnelconstruction. It focused on shallow foundation buildings intersected by the shield tunnel along the north-ern extension of Nanjing Metro Line 1. Field data on building settlements were analyzed, and a numeri-cal model was established using PLAXIS 3D software. The study examined how different horizontaldistances between the tunnel and the building, as well as various crossing angles, affected the charac-teristics of differential settlement and twist deformation. The results showed that as the shield''s excava-tion surface approached the building, the differential settlement and twist deformation of the buildinggradually increased. The differential settlement reached its maximum when the shield machine directlypassed underneath, after which it stabilized. The peak twist deformation occurred when the excavation surface reached the midpoint section of the building, and gradually decreased thereafter. When the ratioof the horizontal distance between the building''s center and the tunnel''s axis to the tunnel''s outer diame-ter ranged from 0.5 to 2 (L/D=0.5~2), the differential settlement of the building was larger, andreached its peak when L/D ratio was 1.5. As the shield crossing angle increased from 0° to 90° , themaximum differential settlement of the building increased accordingly. In contrast, the final twist defor-mation increased first and then decreased, reaching its peak at 45° crossing angle. The research resultsprovide references for similar projects involving shield tunneling passing through shallow foundationbuildings.