富水砂卵石地层土压平衡盾构带压换刀技术

Changing Cutter Tools Technology of Earth Pressure Balance Shield in Water-rich Sandy Gravel Stratum Under Pressure

成都地铁1号线的盾构掘进表明，在砂卵石地层中开挖刀具的磨耗非常严重，平均120～150m需全面更换一次刀具。结合成都地铁1号线盾构3标项目，对浅埋富水砂卵石地层条件下的土压平衡盾构带压换刀技术进行了有益尝试并获得成功，从而形成了相关成套技术。主要包括带压换刀工作气压值的经验计算公式，膨润土泥浆的配合比和制备流程，以及按“到达预定换刀地点前”、“到达时”、“换刀结束后的恢复掘进”三阶段控制的施工工艺。

In excavation of Chengdu Metro Line 1, the cutter tools of earth pressure balance shield are seriously worn in sandy gravel stratum. Generally, the cutter tools should be changed after excavating less than 150 meters. Based on construction of bid 3 of Chengdu Metro Line 1, authors take tests to change cut tools of earth pressure balance shield in water-rich sandy gravel stratum under pressure which finally resulting in success. The related integrated techniques mainly include experience formula of working pressure value, mixture ratio and preparing process of bentonite slurry, and the operation techniques corresponding with different phases.