Abstract：
In the interval between Military Museum Station and East Diaoyutai Station of No.06 segment of Beijing Subway Line 9, the shield tunnel is stuck in water-rich cailloutis-erratic-boulder stratum containing large erratic boulder. After analysis on various parameters of shield machine and stratum conditions and based on practical experiences, various systematic parameters of shield machine are adjusted and special technical measures are adopted for arrangement of shield cutter head and treatment of tunnel face to successfully extricate the shield machine, providing valuable references for similar extrication of shield machine in the future.
