盾构施工新型防结泥饼泡沫剂的研制与应用

针对黏性土层内摩擦角小、黏聚力大、渗透系数低等特点所导致的土压平衡盾构掘进中易发生土体黏附刀盘、土舱结饼堵塞等难题，研制黏土地层专用分散型泡沫剂DCA，并在高液限、强塑性黏性土地层盾构区间进行应用。通过对新型泡沫剂应用期间盾构掘进参数分析以及与同种地层其他泡沫剂的使用情况对比，对泡沫剂的应用效果进行评价。应用结果表明： 1）分散型泡沫剂DCA的碴土改良效果与现场使用的某进口泡沫剂相当，产品性能优于国内同类产品，满足强风化泥岩地层及砂卵石夹泥岩复合地层盾构施工对碴土改良的要求； 2）使用分散型泡沫剂DCA每环可节省10%~15%的材料用量，成本较优，经济效益明显，具有广泛的推广应用价值。

Development and Application of New Foam Agent for Anti clogging of Shield Tunneling

DCA, a special dispersible foam agent for clay stratum, is developed to solve the clogging problems of EPB shield induced by small friction angle, high cohesive force and low permeability coefficient in clay stratum; and it is applied in shield section with high liquid limit and strong plastic cohesive soil layer. By analyzing the tunneling parameters of shield during the application of the new foam agent and comparing with other foam agents in the same stratum, the application effect of the foam agent is evaluated. The application results show that: (1) DCA has the same effect with an imported product used in the field, and the performance of DCA is superior to that of similar products in China, and which can meet the soil conditioning requirements of shield tunneling in strongly weathered mud stone stratum and sandy cobble stratum with mud stone. (2) The application of DCA can save 10%-15% of material consumption per ring with good economic benefit, and which is worth popularizing.