盾构穿越大直径、高强配筋群桩施工方案  

Construction Scheme for Shield Tunneling through Large-diameter Pile Groups with High-strength Reinforcement

作　　者：李洪庆 LI Hongqing(Shenzhen Metro Group Co.,Ltd.,Shenzhen Guangdong 518026,China)

机构地区：[1]深圳地铁集团有限公司,广东深圳518026

出　　处：《交通节能与环保》2022年第6期172-176,共5页Transport Energy Conservation & Environmental Protection

摘　　要：为了解决盾构穿越大直径、高强度、强配筋的桩基群存在的难以切断或排出钢筋以及钢绞线,易造成盾构卡盾、刀盘刀具磨损等问题,本研究依托穗莞深城际轨道交通深圳机场至前海段区间工程,介绍大直径盾构穿越群桩的施工技术方案,保证了盾构安全高效穿越桩基群。采用对盾构机的刀盘各部分设计耐磨保护措施,通过布置焊接撕裂刀,增加刮刀间距,将滚刀刀尖布置成“锯齿”状,在螺旋输送机叶片与筒体内壁焊接耐磨结构等,可以有效降低切削的钢筋缠绕、刀盘及螺旋机被卡的风险。通过在穿越桩基群区段施作MJS水平注浆加固和隧道内全断面注浆措施,达到加固隧道掘进主要影响区内的软弱地层及地下桩基群的目的,可以有效确保地层及上部既有结构的稳定性。施工过程中,通过同布控制盾构姿态、土仓压力、推进速度、同步注浆及二次注浆等盾构掘进参数,进一步确保盾构穿越大直径、高强度、强配筋桩基群施工的安全性。In order to solve the problems of shield tunneling through pile groups with large diameter,high strength and strong reinforcement that are difficult to cut off or discharge reinforcement and steel strand,which are easy to cause shield jamming and cutter wear,this paper introduces the construction technical scheme of large-diameter shield tunneling through pile groups based on the section project between Shenzhen Airport and Qianhai of Guangzhou-Shenzhen Intercity Railway,ensuring that the shield machine can safely and efficiently pass through the pile foundation group.Wear-resistant measures are designed for each part of the cutter head of the shield machine.At the same time,by arranging welding tear knives,increasing the scraper spacing,arranging the hob tip into a shape of"sawtooth",and welding the wear-resistant structure on the blade and the inner wall of the cylinder of screw conveyor,the winding of steel bars and the risk of cutter head and screw machine being stuck can be effectively reduced.Adopting MJS horizontal grouting and full-section grouting of the tunnel in the section of crossing the pile foundation group,the purpose of strengthening the weak stratum and underground pile foundation group in the primary influence zone of tunnel excavation is achieved,and the stability of the stratum and the upper existing structure can be effectively ensured.During the construction,reasonable control of shield tunneling parameters such as shield posture,chamber pressure,propulsion speed,synchronous grouting and secondary grouting is carried out simultaneously to further ensure the safety of shield tunneling through large-diameter,high-strength and strongly reinforced pile groups.

关 键 词：盾构 高强度桩基群 耐磨结构 注浆加固 盾构掘进参数 安全性 

分 类 号：U231.3[交通运输工程—道路与铁道工程]