曲线盾构隧道掘进引发机场地下油管沉降变形分析

Research on Airport Tubing Settlement Caused by Shield Tunnelling in Curved Section

机场磁浮盾构隧道掘进过程会对机场跑道和地下油管产生扰动,严重时会影响机场安全运营,造成重大经济损失。为揭示机场磁浮曲线段盾构隧道掘进过程中引发的地下油管变形扰动效应,采用理论计算、数值模拟及现场监测的方法,研究曲线段盾构隧道下穿引起地下油管的沉降变形。结果表明:盾构机在曲线段掘进过程中,地下油管横向沉降槽将会偏离隧道中轴线,在曲线隧道内侧的地下油管沉降明显大于曲线隧道外侧的地下油管沉降;盾构开挖面附加推力t、盾壳摩阻力f以及附加注浆压力g导致地下油管沉降的横向分布呈“U”型,盾壳摩阻力和地层损失是显著影响因素;三种方法下的地下油管变形结果相近,验证了理论计算方法的正确性和适用性。

The excavation process of the airport maglev shield tunnel will cause disturbance to the airport runway and underground tubeing,and in severe cases,it will affect the safe operation of the airport and cause significant economic losses.In order to reveal the deformation disturbance effect of the underground tubeing caused by the shield tunnel in the airport maglev curved section,the settlement deformation caused by the shield tunnel in the curved section passing through the underground tubing was studied based on theoretical calculation,numerical simulation and on-site monitoring.The results show that during the tunnel excavation process of the curved section,the lateral settlement trough of the underground tubing will deviate from the central axis of the tunnel.On the inner side of the curved tunnel where the curvature is small,the settlement of the underground tubing is significantly larger than that on the outside of the curved tunnel;the additional thrust t on the shield excavation surface,the shield friction f and the additional grouting pressure g cause the lateral distribution on the subsidence of the underground tubing to be in the shape of"U",and the significant influencing factors are the shield friction and the ground loss;the deformation results of the underground tubing under the three methods are similar,which verifies the theoretical calculation method.