芜湖长江公路二桥钢护筒制作、运输与沉放技术

摘要

Based on the installation of steel casings for the piles for the southern main pier for Wuhu Second Changjiang River Highway Bridge, the paper expounds on the features, fabrication, transportation and control, and installation of steel casings for the pile foundation for southern main pier, mainly including the factory processing of large steel casings with spiral welding, internal and external multi-point supports for transportation, vibro-driving of steel casings with twin vibratory hammers from a large floating crane, positioning of twin guide frames with double orientation and double guiding, and high torque rotary drill to clear boreholes followed by second vibro-driving of the steel casing. The results show that the methods employed have effectively controlled the quality of fabrication of the steel casings and the deformation of steel casings during their transportation, and have improved the positioning accuracy of steel casings.%以芜湖长江公路二桥南主墩桩基钢护筒施工为工程背景，阐述了南主墩桩基钢护筒特点、制作工艺、运输控制、沉放方法等，主要包括采用工厂化加工螺旋焊缝超大钢护筒、多支点内外支撑运输、大型浮吊配合双联振动锤施振、双层双导向双联导向架定位、大扭矩回旋钻扫孔再施振的二次跟进工艺等。结果表明此技术有效控制了钢护筒加工质量和运输过程中的变形，提高了钢护筒定位精度。