苏通GIL综合管廊盾构法地面变形特征及预测研究

Study on the Characteristics and Prediction of Tunneling-induced Ground Movements in Sutong GIL Utility Tunnel

苏通GIL综合管廊盾构隧道是世界上最长的水下电力隧道,由于穿越地层地质情况复杂、掘进纵向坡度大,给盾构掘进引起的地表变形控制带来巨大困难。通过盾构掘进开挖施工下地面变形现场监测,深入分析泥水盾构掘进引起的地面变形模式和发展规律,发现地面最终沉降规律与经验法所提出的正态分布模式保持一致。针对隧道盾构引起地层移动预测经验法中沉降槽宽度确定问题,先在南岸依据现场地质勘查资料确定不同方法对应的沉降槽宽度,通过与实测结果对比分析这些沉降槽宽度计算方法的适用性;后采用Clough&Schmidt法对北岸断面进行预测,与现场监测结果基本一致,为盾构现场施工安全控制提供重要指导。

Sutong GIL shield-driven tunnel,the longest underwater tunnel in the world,has complex geological conditions and large longitudinal inclination of tunneling,which makes it very difficult to control the ground surface deformation caused by excavations.Based on the monitoring of ground deformation during excavation and the deeply analysing of the ground deformation pattern and development law caused by slurry shield,it is found that the final settlement law of the ground is consistent with the normal distribution model proposed by the empirical method.To determine the width of settlement trough in the empirical method for prediction the ground surface deformation,the widths of settlement trough corresponding to different methods are firstly determined on the south bank according to the field geological survey data,and then compared with the measured results to determine the applicability of these calculation methods.Finally,Clough&Schmidt method is adopted to predict the deformation of the north bank,which is basically consistent with the field monitoring results and provides important guidance for the safety control of shield construction.