大直径盾构隧道侧穿高架桥桩数值模拟研究

Numerical Simulation Research on Large Diameter Shield Tunnel Crossing Viaduct Piles

上海机场联络线大直径盾构侧穿G60高架桥桩,距离主线桥桩净距仅为0.9m,盾构掘进产生的地层损失,必将使桥桩发生变形。采用数值模拟方法,研究盾构隧道穿越桥桩时,采取加固措施前后桥桩的变形及内力响应。结果显示:当未采取加固措施时,南匝道、主道和北匝道桥桩的最大竖向位移超出了10mm的控制值;当采取袖阀管注浆与MJS加固后,增大了地层抗力,减少了桥桩变形,计算得到桥桩变形均满足要求,桥桩的附加弯矩较小,结构强度满足要求,验证了加固措施的有效性。

The large-diameter shield tunnel of the Shanghai Airport link line passes through the G60 viaduct piles,and the net distance from the main line bridge piles is only 0.9m.The ground loss caused by the shield tunneling will inevitably deform the bridge piles.In this paper,numerical simulation method is used to study the deformation and internal force response of the bridge piles when the shield tunnel passes through the bridge piles before and after reinforcement.The results show that when no reinforcement measures are taken,the maximum vertical displacement of the bridge piles of the south ramp,the main road and the north ramp exceeds the control value of 10mm.When the sleeve valve pipe grouting and MJS are used for reinforcement,the stratum resistance is increased and the bridge pile deformation is reduced.The calculation results show that the bridge pile deformation meets the requirements,the additional bending moment of the bridge pile is small,and the structural strength meets the requirements.The reinforcement is verified,the effectiveness of the measures.