As a sophisticated tunnel lining type,the universal wedge-shaped segments can do a good job in the control of the axis of the shield-driven tunnel and the quality of the segment ring.

As a sophisticated tunnel lining type,the universal segments were applied widely in the construction of shield-driven tunnel.

The influence to the radiation quality by the wedge filter;

Methods First, we measured the dose rate with and without containing 60°wedge filter for different field and depth on Siemens MD7745 linear accelerator by Capintec292, then we got the Fw for different fields and depths,after then,we calculated the deviations under the two conditions that we assume the Fw (10 cm × 10 cm, d= 10 cm) or the Fw (10 cm × 10 cm, dmax =1.