Abstract: During shield tunneling in curved section, it is difficult to control the axis, resulting in attitude deflection, segment damage and dislocation, and hard in correcting deviations. As a result, case studies are conducted on Shenzhen and Fuzhou metros, and the method of designing linear deflection amount is taken as the linear deflection amount when shield tunneling in curved section and segment assembly, so as to realize three line in one(i.e., design axial line, shield tunneling curved line, and segment assembly line) and further control shield attitude and segment assembly line. The design deflection amount is calculated according to the turning radius of the curved section, the left and right cylinder strokes are controlled according to the design deflection amount during the propulsion process, and the segment assembly points are reasonably selected according to the deflection amount of the shield propulsion curve to achieve threeline coaxiality. The application of the method recommended in Shenzhen metro shows a good effect.

Key words: tunnel, shield curve, deflection, design axis