岩溶地区盾构掘进施工参数研究

STUDY ON THE CONSTRUCTION PARAMETERS OF SHIELD TUNNELLING IN KARST STRATA

根据某地铁实测数据,分析总结了地质条件(溶洞分布与大小)、盾构尺寸、施工参数对隧道轴线偏差与地表沉降的影响规律,提出了保护环境的盾构施工控制工艺与参数。施工参数的影响为:总推力随着刀盘扭矩的增大而增大;掘进速度随着螺旋机转速的增大而增大;通过调整掘进速度和螺旋机转速的大小控制土压力。在岩溶地层砂土灰岩界面进行盾构隧道施工时,垂直轴线要低于盾构设计轴线,须根据渣土判断掌子面软土和岩石比例,及时调整盾构施工参数,避免产生过大的地表沉降。

Based on the data of Metro Line 9 in Guangzhou, the influence of geological conditions （the distribution and size of karst cavern）, tunnel geometry and operational parameters on tunnel axis deviation and surface settlement was summarized, and environmental friendly technic and parameters was proposed. The influence of the construction parameters was as follows. The thrust increased as the disk torque increased, and the advance rate increased as the screw rotation rate increased. The soil pressure could be controlled by adjusting advance rate and screw rotation rate. During the tunnelling construction in interface between karst cavern and sandy strata, the vertical alignment should be lower than the alignment designed, and the operational parameters should be timely adjusted according to the ratio of soft soil to rock at the excavation face in order to avoid significant surface settlement.