受限空间内盾构三阶段分体始发施工技术研究

Study on Three-stage Split Launching Technology of Shield in Confined Space

盾构始发井空间受限时,无法进行正常整体始发,因此盾构机采用分体半环始发工艺。其工艺流程包括3个阶段:初始掘进阶段采用10 m3小土斗出土,并辅助以负环半环拼装和延伸管线导向架工艺;待掘进距离满足设备连接桥及1号台车下井后,完成二次组装;试掘进阶段完成120 m后,管片与土体间摩擦力和盾构机推力得以平衡,则完成三次组装,采用电瓶车双编组进行正常掘进。结果表明,相比于常规分体始发施工手段,三阶段分体始发工艺在进一步压缩始发过程空间需求的基础上,很好地平衡了掘进进度及空间利用的难度,节约工期可达30%,对后续受限空间工况下盾构始发作业有极大借鉴意义。

When the space of the shield launching shaft is limited,the normal overall launching cannot be performed,so the shield machine adopts the split half-ring launching process.The process flow consists of three stages:in the initial excavation stage,a 10 m3 small soil bucket is used for unearthing,assisted by the semi-ring assembly of the negative ring and the guide frame process of the extension pipeline;when the excavation distance meets the requirements for the equipment connection bridge and the No.1 trolley to descend into the well,the secondary assembly is completed;after the completion of 120 m in the trial excavation stage,the friction between the segment and the soil and the thrust of the shield machine are balanced,then the third assembly is completed,and normal excavation is carried out using the double grouping of battery cars.The results indicate that,compared with the conventional split launching construction method,the three-stage split launching process balances the tunneling progress and the difficulty of space utilization while further compressing the space requirements of the launching process,saving the construction period by up to 30%.This process is of great reference significance for subsequent shield launching operations under confined space conditions.