兰州地铁下穿黄河段同步注浆的浆液试验研究

针对兰州地铁下穿黄河砂卵石地层,在盾构掘进中能更好的控制同步注浆的浆液性能,通过对砂卵石地层同步注浆的浆液性能要求配制8组不同的配合比,试验测试:浆液密度、浆液流动度、浆液塌落度、稠度、凝结时间、水下浇注试验、抗水冲的分散试验、析水率以及试件的抗压强度,得到膨润土可以提高浆液的稳定性;黏土粉的加入,使注浆浆液的粘聚能力增大,提高了浆液整体性和抗水性,但是添加了黏土粉的浆液流动性明显降低;浆液的含水量和黏土粉的含量决定浆液凝结时间和流动性的主要因素.进而得到浆液的配合比为:水25%~30%、膨润土6%、水泥6%~7%、细沙35%~40%、黏土粉与粉煤灰20%~25%.为以后盾构穿越黄河砂卵石地层提供参考.

Slurry of Lanzhou Metro under the Synchronous Grouting in the Yellow River Section

The slurry performance of synchronous grouting can be better controlled by shield tunneling in Lanzhou Metro under the Yellow River Sandy Cobble Stratum.The performance of slurry grouting in sand and gravel stratum was investigated by 8 groups of different proportioning.The slurry density, slurry fluidity, slump, consistency, setting time, water pouring test, anti water dispersion test and water separation rate and compressive strength were tested.Get the bentonite grout improves the stability of the pump;adding clay powder,the grouting cohesive capacity increases,improves the overall size and water resistance,but the addition of clay powder slurry, the slurry fluidity decreased, water content and clay content are the main factors of slurry condensation time and liquidity.The proportion of the obtained slurry is as follows:water 25% to 30%, bentonite 6%, cement 6% to 7%, fine sand 35% to 40%, clay powder and fly ash 20%to 25%.This will provide reference for shield tunneling through the Yellow River sand gravel stratum.