浅谈泡沫技术在土压平衡盾构中的应用

On the Application of Foam Technology in the Earth Pressure Balance Shield

土压平衡盾构是软土地区地铁隧道施工的主要方法之一。但是盾构在穿越流塑性差、含水量高、渗透系数大的砂性土层时,存在土体受扰动发生液化、推进速度慢、刀盘形成"干饼"等一些技术难题。使用泡沫不仅有利于保持开挖面土压力平衡,而且机械负荷及刀盘扭矩能够明显减少,解决施工难题,并保证开挖面的稳定和砂性流塑的优点。

The earth pressure balance shield is the main method of constructing the shield tunnel in the soft soil area. While shielding the sandy soil which is of bad thixotropy, high water and permeability coefficient, there will be some technical problems, such as liquefied while disturbing, advancing slowly, deforming cutters and so on. The foam technology can not only keep the soil pressure balance of the excavation face but also reduce the mechanical load and cutter torque. Therefore, it solved the technical problems and ensured the stability of the excavation face and merits of thixotropy soil.