【摘要】 针对某隧道土压平衡（EPB）盾构穿越富水砂卵石地层的工程难题，开展室内渣土改良试验，对泡沫、钠基膨润土泥浆及衡盾泥3种改良剂及改良渣土性能试验、坍落度试验与渗透试验，结果表明：泡沫体积分数为3%，注入比为20%；钠基膨润土泥浆质量浓度为235 g/L，掺入比为1∶10；衡盾泥A液∶B液配合比为18∶1（掺入比1∶25）或21∶1（掺入比1:20）,3种改良方案均满足渣土施工所需的和易性及抗渗性要求。泡沫改良渣土的渗透系数最小，但其临界水力坡降仅为10.9；钠基膨润土改良渣土和衡盾泥改良渣土均表现出较强的抗渗稳定性，其中钠基膨润土改良渣土抗渗效果最佳，水力坡降达到34.9时，其渗透系数仍能维持在10^-5cm/s数量级，但泥浆用量较大，衡盾泥则在用量相对较少的情况下，其临界水力坡降为19.3，在3种改良剂中综合性能最为均衡。将衡盾泥改良方案应用于施工实践，实测改良后刀盘与螺旋输送机扭矩均有所降低且数值更稳定，螺旋输送机喷涌现象消失。该研究可为后续类似富水砂卵石地层土压平衡盾构施工的渣土改良提供量化依据。更多还原

【Abstract】 Aiming at the technical challenges of an Earth Pressure Balance（EPB） shield tunneling through water-rich sandy cobble strata, laboratory conditioning tests were conducted to investigate three conditioning agents of foam,sodium bentonite slurry and Hengdun mud by performance evaluation, slump tests, and permeability experiments.The results indicate that the foam volume fraction is 3% with an injection ratio of 20%; sodium bentonite slurry concentration is 235 g/L with a mixing ratio of 1∶10; and Hengdun mud component A to B ratio is 18∶1（mixing ratio 1∶25）or 21∶1（mixing ratio 1∶20）. All three improvement schemes meet the workability and anti-seepage requirements for muck operations. Foam-conditioned muck exhibits the lowest permeability coefficient but its critical hydraulic gradient is only 10.9. Both sodium bentonite slurry and Hengdun mud demonstrate superior anti-seepage stability.Sodium bentonite-conditioned muck achieves the best impermeability performance, maintaining a permeability coefficient on the order of 10^-5cm/s even at a hydraulic gradient of 34.9 with higher slurry consumption. Hengdun mud, while requiring relatively lower dosage, achieves a critical hydraulic gradient of 19.3, representing the most balanced overall performance among the three conditioners. The Hengdun mud conditioning scheme was implemented in construction practice, resulting in reduction and more stabilization of torque values of both the improved cutterhead and screw conveyor, without spewing phenomena of the screw conveyor. This research provides quantitative references for muck conditioning in subsequent EPB shield tunneling projects under similar water-rich sandy cobble geological conditions.更多还原