Abstract：
During interval tunnel shield construction of Beijing Subway Line 9 between Fengtai Kejiyuan Station of Keyilu Station, based on field conditions, various measures were adopted, such as reducing the volume of trolley, setting transverse belt, laying rightward opening switch and simultaneous U-turn of shield machine and trolley in north-south shield shaft, etc., to realize the transition from separate launching into integral launching, successfully reducing secondary connection of trolley and secondary debugging of shield machine which are required for separate launching, and saving the construction schedule and cost. The safety of south fourth ring road where there is high potential risk was guaranteed and favorable social and economic benefit was realized.
