大型曲线沉管出轴线干坞测量控制

On the Survey Control for the Large-Scale Curved Immersed Tube Getting Out of the Axis Dry Dock

天津中央大道海河隧道轴线干坞坞口设计宽度最小值为40.6m,而曲线沉管长85m,宽36.6m,高9.65m,重约3万t。如此庞然大物穿过富裕宽度只有1.86m的坞口,沉管姿态的测控难度及精度要求极高。出坞过程中,通过在沉管顶部布设轴线控制点,保证沉管轴线与隧道设计轴线重合,使曲线沉管顺利出坞。介绍了不同管段出坞及坞内移动的测量控制过程,对同类工程有借鉴意义。

The minimum value of the designed width of the dock entrance of the axis dry dock of the Haihe Tunnel of the Central Avenue in Tianjin is 40.6 m,and the curved immersed tube is 85 min length,36.6 min width,9.65 min height and 30000 tin weight.When such a huge object goes through the dock entrance only 1.86 min width,the difficulty in measuring and controlling the posture of the immersed tube and the requirement for the accuracy of the measurement are extremely great.In the course of the moving-out-of-dock operation,the coincidence of the axis of the immersed tube and the designed axis of the tunnel is ensured through arranging the axis control points on the top of the immersed tube so as to help the curved immersed tube smoothly go out of the dry dock.The measuring and controlling processes for the various segments coming out of the dry dock and moving inside the dry dock are introduced in the paper,which may serve as a useful reference for other projects of the same type.