富水复合砂层大直径盾构掘进同步注浆性能配比试验研究

针对广佛环城际铁路大直径盾构隧道掘进地段富水复合地层的地质条件,选择具有充填速度快,保水性好,离析率低等性能的同步注浆材料,设计均匀试验测定不同配比下单液浆的物理力学性能参数,对结果采用多目标规划方法优化分析。试验结果表明:选取质量比为水泥∶粉煤灰∶黏土∶生石灰∶硫酸钠∶水=1∶2.56∶0.30∶4.90∶2.32的浆液,能同时满足适用于富水地层的流动度和凝结时间,泌水率较低,强度高和经济效益较高等多约束条件。对砂浆配合比优化前后进行对比试验,结果显示采用最优配合比砂浆的性能有较明显的改善。

Experimental Study on the Optimization of Mixture Ratio of Synchronous Grouting for Large-diameter Shield Tunneling in Water-rich Sandy Ground

According to the geological conditions of the large-diameter shield tunneling in water-rich complex strata in Guangzhou-Foshan intercity railway,uniform test is conducted to determine the physical and mechanical parameters of the single fluid grout under different mixing ratio with synchronous grouting material of rapid filling,strong water retention,non-segregation and low decantation rate. The multi objective programming method is used to analyze the results. Experimental results show that the grouting slurry with the quantity ratio of cement,fly ash,clay quicklime,sodium sulfate and the water content as1 ∶ 2. 56 ∶ 0. 30 ∶ 4. 90 ∶ 2. 32 respectively can meet the constraints related to the fluidity of saturated water strata and the suitable setting time,low bleeding rate,high strength and high economic benefits.The test results show that the performances of the grouting slurry with the optimum mix ratio are improved remarkably.