卵石土及泥岩侵入地层中泥浆配比试验研究

泥浆支护是泥水盾构实现安全掘进的关键，泥浆压力是否能快速有效的传递到开挖面将影响地层的稳定性控制，而泥浆的配比将直接影响泥浆压力的转化。为保证泥浆在卵石土及泥岩侵入地层中的支护效率，本文以成蒲铁路紫瑞隧道工程为依托，开展了一系列泥浆渗透成膜试验以确定泥浆的合理配比。研究结果表明：泥浆的配比对盾构掘进的效率有明显影响，密度和粘度偏小的泥浆会导致泥浆滤失量过大，泥浆压力不能及时形成；而密度和粘度偏大的泥浆会导致刀盘泥饼的产生，降低盾构掘进效率。本文通过泥浆渗透试验与现场实测，在有效成膜和防结泥饼之间确定了最佳的泥浆配比。该泥浆配比的确定及调整方案在现场取得了良好的效果，以期为泥水盾构在类似地层中施工提供参考。

Experimental Study on the Composition of Slurry in the Pebble Soil and Mudstone Intrusive Strata

Slurry support is the key to the safety of the excavation face during tunnelling by slurry shields. Whether the slurry pressure can be quickly and effectively transmitted to the excavation face will affect the stability of the ground, and the composition of the slurry will directly affect the conversion of the slurry pressure. To ensure the effectiveness of the slurry support in the pebble soil and mudstone intrusive Strata, a series of slurry penetration tests were carried out based on Zirui Tunnel in Chengpu Railway Project. The results show that the composition of slurry has a significant impact on the efficiency of tunneling. Slurry with low density and viscosity will lead to excessive filtration loss and the required pressure cannot be formed in time. The slurry with high density and viscosity will lead to the formation of cutter cake and reduce the efficiency of tunneling. In this paper, through slurry penetration test and field measurement, the best slurry ratio between pressure built and preventing cake formation is determined. The determination and adjustment of the composition of slurry have achieved good results in Zirui Tunnel, which can provide reference for slurry shield construction in similar stratum.