土压平衡盾构在砂卵石地层中穿越城市河流施工关键技术

Key Construction Technologies for Earth Pressure Balanced Shield Machine Boring in Sandy Cobble Strata across River

北京地铁10号线二期工程(公主坟站—西钓鱼台站区间和西钓鱼台站—慈寿寺站区间)盾构区间在砂卵石地层长距离下穿昆玉河,为了摸索出一套适合土压平衡盾构砂卵石地层下穿城市河流的施工方法,通过在穿河之前设置试验段优化施工参数,穿越期间有效控制土仓压力、盾构推进速度、螺旋输送机出土速度,调整注浆压力、注浆量和盾尾油脂用量,及时进行同步注浆和二次补浆等技术措施,盾构成功穿越河流并解决了螺旋输送机喷涌、被卡等重大风险,保证了河堤变形在产权单位要求的范围内,为今后类似工程积累了施工经验。

The shield-bored tunnel section of phase 2 of line 10 of Beijing Metro crosses Kunyu river. The tunnel is loca- ted in sandy cobble strata. Technologies, including optimizing the boring parameters before river-crossing, bringing the pressure in the excavation chamber, the driving speed of the shield machine and the muck releasing speed of the screw conveyor under effective control during fiver-crossing, adjusting the grouting pressure, the grouting volume and the tail sealing grease volume, executing simultaneous grouting and secondary grouting, are applied. In the end, the shield ma- chine crosses the river successfuly and the deformation of the riverbank is within the allowable range. The paper can pro- vide reference for similar projects in the future.