基于盾构影响的长江砾石层工程地质研究

Engineering geological study on Yangtze River gravel stratum based on shield machine influence

拟建长江盾构地铁隧道(江心洲站—中间风井区间)局部穿过长江砾石层,砾石层中卵石、砾石等颗粒级配,最大粒径、大粒径卵石、砾石含量,砾石层密实度以及卵、砾石单轴抗压强度对盾构刀盘选型、盾构掘进均产生影响。基于盾构影响的角度结合工程实践,采用水上钻探方法,详细查明长江大盾构隧道所穿越砾石层的工程地质特性。结果表明,长江大盾构隧道所穿越砾石层的工程地质特征要求盾构掘进遵循排小碎大的原则,合理选择盾构刀盘的开口尺寸、开口率、滚刀刃间距等,并加设耐磨保护装置,注入改良渣土的泡沫试剂等,掘进时合理控制盾构推进的速度、转速和锥入度,为工程实际中过江大盾构选型、盾构掘进施工提供地质依据。

Based on shield machine, in combination with the engineering examples, the overwater drilling method was adopted and then the engineering geological special properties of the gravel stratum passed through by the Yangtze River shield tunnel could be investigated in details. It was shown that the engineering geological special properties of the gravel stratum passed through by the Yangtze River shield tunnel demonstrated that the shield tunneling should follow the regulations that the smaller gravels and cobbles would be discharged and the bigger gravels and cobbles would be crashed. The opening vent size, the opening vent rate, the edge distance of the roller cutter and so on should be decided in reason. Meanwhile, the abrasion resistant protection equipment should be installed and the foam reagent should be added to improve the discarding soil. And the shield tunneling, the tunneling speed, the rotational speed and the penetration degree of the shield machine should be controlled in reason. The work above would provide geological bases for the shield machine selection and tunneling process.