大直径盾构双线隧道下穿高铁车站的受力变形研究

Study of Mechanical and Deformation Characteristics of Large-diameter Double-line Shield Tunnel under-crossing High-speed Railway Station

针对广州地铁十八号线大直径盾构双线隧道近距离下穿佛莞城际番禺大道站,建立三维地层-结构有限元模型,研究了车站结构和盾构隧道的受力和变形特征,并结合现场监测数据进行对比。研究结果表明:车站结构及隧道变形计算结果均小于规范限值,车站地连墙、底板弯矩增量稳定;实测车站结构沉降和水平位移最大值均发生在盾构双线施工完成,并与有限元计算结果接近;双线盾构的掘进对车站侧墙、抗拔桩和隧道水平位移的影响主要发生在左线掘进过程中;车站结构的内力和变形的变化趋势与盾构施工密切相关,右线、左线盾构依次掘进对车站底板沉降影响具有叠加效应。研究结果可为大直径盾构近距离下穿建筑物受力变形影响分析提供参考。

Regarding the large-diameter shield tunnel of Guangzhou Metro Line No.18 under-crossing Foguan Intercity Railway Panyu Avenue Station in a short distance,a three-dimensional stratum-structure finite element model is established by using MIDAS GTS to study the stress and deformation characteristics of the station structure and shield tunnel,and comparisons are carried out based on the onsite monitoring data.The results show that the calculation results of the station structure and tunnel deformation are less than the limit value,and the increment of bending moments of the continuous wall and bottom slab are stable.Both the maximum of measured subsidence and the horizontal displacement of the station structure occur when the double-line tunnel construction is completed,which are close to the finite element calculation results.The influence of double-line shield tunneling on the lateral wall,pile pulling and horizontal displacement of the tunnel mainly occurs in the process of left-line tunneling.The variation trend of the internal force and deformation of the station structure is closely related to the shield construction.The research results can provide reference for the analysis of the deformation influence of large diameter double-line shield tunnel under-crossing structure.