小间距双线隧道CRD法零距离下穿既有营运车站变形影响研究

以深圳地铁7号线皇岗村站至福民站的新建小间距双线平顶隧道施工区间工程为例,研究采用CRD法+直墙暗挖进行零距离下穿既有4号线福民站,对其结构变形影响及现场监测结果分析。通过对新建双线隧道施工全过程的精细化数值仿真模拟,揭示既有营运车站的变形规律,为施工过程中结构变形发展预测和设计方案实时调整提供理论支撑。结合施工过程实时监测资料,论证新建隧道下穿施工对既有车站的影响程度,验证当前设计方案的可行性。结果表明,数值仿真分析的既有车站变形规律与实际监测结果一致,且最大变形量均小于控制值10.0 mm。

Analysis of the Impact of Subsurface Excavation of Double Line Running Tunnel with CRD Method under Existing Operating Station

Based on the project of Shenzhen Metro Line 7 from Huanggang Village Station to Fumin Station,which is a newly-built parallel tunnel with zero distance and flat roof,the influence on structural deformation caused by tunnel construction beneath adjacent existing Fumin Station employing crossdiaphragm( CRD) method and straight-wall concealed excavation method,and filed monitoring results are analyzed. The refinement numerical simulation of the whole construction process of the double line tunnel reveals the deformation law of the existing station and provides theoretical support for the prediction of structure deformation and real-time adjustment of designing scheme. The real time monitoring data demonstrate the impact on the existing station and verify the feasibility of the current design. The results show that the deformation law of the existing station demonstrated by the numerical simulation analysis is consistent with the actual monitoring results,and the maximum deformation is 10. 0 mm less than the controlling value.