理论研究 2024年 第53卷 第21期

DOI: 10. 7672 / sgjs2024210071

曲线盾构隧道下穿施工影响分析

黄毅¹,何健¹,张家硕¹,畅继鹏¹,李俊华²,黄强²

作者简介:

黄毅,高级工程师,E⁃mail:huangy@ nbmetro. com

作者单位:

1.宁波市轨道交通集团有限公司建设分公司,浙江宁波 315101;2.宁波大学土木工程与地理环境学院,浙江宁波 315211

基金项目:

∗宁波市自然科学基金项目(2023J083)

摘要:

依托宁波地铁 6 号线某区间曲线盾构隧道下穿既有车站工程实例,基于 Midas GTS NX 软件进行三维数值建模,模拟隧道下穿施工全过程,分析上部车站底板、隧道结构、地表变形变化规律。基于数值计算结果对曲线隧道下穿施工安全进行评价,提出变形控制措施。研究结果表明,曲线盾构隧道施工时由于内侧超挖造成更大的地层损失,对车站底板沉降造成叠加影响,隧道开挖完成后车站底板最大沉降位于双线隧道中心;左线隧道开挖完成时,竖向收敛变形呈中间小、两端大的分布特点,且右线隧道施工对左线隧道竖向收敛变形的影响较小;曲线隧道下穿施工引起的地表沉降变形主要集中在双线隧道中心两侧 25m 范围内;通过采取必要的变形控制措施,可使结构变形处于安全范围内。

English:

Based on the engineering example of a curve shield tunnel of Ningbo Subway Line 6undercrossing an existing subway station, three⁃dimensional numerical simulation was carried out basedon Midas GTS NX software, the whole construction process of tunnel undercrossing was simulated, anddeformation characteristics of the upper station floor, tunnel structure and ground surface were analyzed.Based on the numerical calculation results, the construction safety of curve shield tunnel undercrossing isevaluated, and the deformation control measures are put forward. The research results show that duringthe curve shield tunnel construction, the ground loss caused by the ove excavation of the inner side isgreater,which has a superimposed impact on the settlement of the station floor, and the maximumsettlement of the station floor is located at the center of the double⁃line tunnel when the tunnel excavationis completed. When the excavation of the left line tunnel is completed, the vertical convergencedeformation is smaller in the middle and larger on both sides, the construction influence of the righttunnel on the vertical convergence deformation of the left tunnel is smaller. The surface settlement causedby the undercrossing construction by the curve shield tunnel is mainly concentrated within 25m away fromthe center of the double⁃line tunnel. By taking necessary deformation control measures, the structuredeformation can be kept within the safe range.