地铁车辆段出入线大盾构小间距超浅埋下穿河流安全施工技术

针对成都地铁18号线合江车辆段出入线大盾构小间距超浅埋下穿东风渠工程,提出了用黏土换填河底的淤泥、施工隔水层和抗浮压板、控制盾构掘进参数、改良渣土以及壁后二次保压注浆的综合措施,有效解决了下穿河流安全施工风险问题,提高了盾构隧道管片结构的抗浮能力,产生了良好的社会经济效益。建立了大盾构小间距超浅埋下穿河流安全施工技术,为今后类似工程提供技术参考。

Safe Construction Technology on Access Tunnel Built by Large Diameter Shield Undercrossing River with Little Distance and Ultra-Shallow Cover for Metro Train Depot

The case study was conducted on the project about Hejiang Depot Access Tunnel built by large diameter shield undercrossing Dongfeng River with little distance and ultra-shallow cover for Chengdu Metro Line 18, the comprehensive measures of replacing silt with clay at the bottom, constructing waterproof layer and anti-floating plate, controlling driving parameters of shield, and conditioning ground and grouting behind the segment for the second time were put forward. The safety hazards of construction undercrossing the river were effectively solved, the anti-floating capacity of segment structure of shield tunnel was improved and good social and economic benefits were generated. The safe construction technology of large diameter shield undercrossing river with little distance and ultra-shallow cover was established to provide technical references for similar projects in the future.