高抗渗注浆材料在水下地铁隧道地层加固中的研究与应用

Study and Application of High-impervious Grouting Material to Ground Reinforcement of Underwater Metro Tunnel

为探讨高抗渗注浆材料在水下地铁隧道地层加固中的应用,采用普通水泥浆液掺加无碱速凝剂和高效减水剂的形式制备高抗渗注浆材料,通过室内试验分析普通水泥浆液在不同外加剂掺量条件下的浆液性能,以凝结时间、流动度和抗渗性能为主要指标对浆液的配比进行设计。室内试验结果表明,水灰比在0.65~1.0,调整浆液配合比,浆液流动度可达到230~270 mm,初凝时间小于2 h,抗渗等级大于P8,满足施工要求。在厦门地铁3号线五缘湾站—会展中心站区间斜井暗挖隧道现场2个循环注浆试验中,确定了3种注浆配比的应用条件,通过加固体强度和抗渗性2项指标实验分析,验证了高抗渗注浆材料具有良好的抗渗及加固地层效果。

The high-impervious grouting material prepared by Portland cement,alkali free additive and high-efficient water reducer is used in ground reinforcement of underwater metro tunnel. The performances of Portland cement grout,i. e. setting time,fluidity and impermeability,under different mixing proportions of additives are analyzed by indoor test. The test results show that the fluidity of the grout can reach 230-270 mm; the setting time of the grout is less than2 h and the impermeable grade is higher than P8 when the water-cement ratio reaches 0. 65-1. 0. Finally,the applicable conditions of grout under 3 proportions are determined by grouting test of prepared grout in mined tunnel of inclined shaft of Wuyuan Bay Station-Convention Center Station Section on Line No. 3 of Xiamen metro; the ground reinforcement effect of the high-impervious grouting material is testified by strength and impermeability of the ground reinforced.