安庆长江铁路大桥桥塔墩钻孔桩施工关键技术  

Key Techniques for Construction of Pylon Pier Bored Piles of Anqing Changjiang River Railway Bridge

作　　者：刘爱林 

机构地区：[1]中铁大桥局宁安铁路安庆长江大桥工程指挥部,安徽安庆246008

出　　处：《桥梁建设》2013年第5期12-17,共6页Bridge Construction

摘　　要：安庆长江铁路大桥主桥为(101.5+188.5+580+217.5+159.5+116)m双塔三索面钢桁梁斜拉桥,3号、4号桥塔墩均采用37根3.4(3.0)m变直径钻孔摩擦桩基础,桩长分别达108m、110m。3号、4号桥塔墩基础均采用双壁钢围堰施工方案,通过人工创建稳定地层施工环境,利用KTY4000型钻机完成清水法钻孔,钻孔到位后利用钻机进行第1次清孔,采用JJC-1D超声波成孔检测仪定量检孔,检测合格后移开钻机,下放钢筋笼和导管,利用导管进行第2次清孔,再灌注桩身水下混凝土,完成桩基施工。该桥桥塔墩桩基施工过程中未发生任何掉钻及断桩事故,经超声波无损检测均为Ⅰ类桩。The main bridge of Anqing Changjiang River Railway Bridge is a steel truss girder cable-stayed bridge with double pylons,triple cable planes and with span arrangement（101.5＋188.5＋580＋217.5＋159.5＋116） m.The pylon piers No.3 and No.4 of the bridge are all supported on the foundations that are respectively made up of 37 nos.of the φ3.4 （3.0） m variable diameter frictional bored piles with the length of the piles being up to 108 m and 110 m.The foundations for the pylon piers were constructed by the double-wall steel cofferdam scheme.By way of the artificial effort,the construction environment of the stable stratum was created,the bored holes of the clear water method were completed,using the KTY4000 boring machine.After the holes were bored to the designed elevation,the holes were cleared off for the first time by the boring machine and the holes were then quantitatively inspected,using the JJC-1D Bored Hole Ultrasonic Inspection Instrument.Further after the holes were proved to be qualified through the inspection,the boring machine was removed away,the reinforcement cages and tremie ducts were lowered into the holes and the holes were cleared off for the second time through the ducts.Finally the tremie concrete for the piles was cast to complete the construction of the pile foundations.In the construction of the piles,no accidents like the falling of the boring bits and breaking of the piles took place and the piles were all qualified as Class Ⅰ piles according to the inspection.

关 键 词：铁路桥 斜拉桥 桩基础 钻孔摩擦桩 桥梁施工 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.551[交通运输工程—道路与铁道工程]