城市钢箱梁高架桥球形支座安装施工工艺

城市钢箱梁高架桥球形支座安装主要控制安装方向、高程、位移等;球形支座安装前进行基础复测及支座顶板与钢箱梁底板焊接,焊接采用焊条电弧焊方法,并进行焊前温度不低于200℃预热处理。球形支座安装用钢楔形垫块将下支座板四角调平。球形支座灌浆先灌地脚螺栓孔,灌完24h达到强度后再灌支座底面预留的灌浆层,最后拆除四角钢楔形垫块用环氧砂浆填满垫块位置。钢箱梁卸载后进行焊接垫板与钢箱梁底板焊接,焊接完毕后拆除临时连接件,并安装防尘罩。支座高程允许偏差控制在±3mm以内,支座偏位允许偏差控制在2mm以内。

ASSEMBLING CONSTRUCTION TECHNOLOGY OF STEEL BOX GIRDER SPHERICAL BEARING FOR CITY VIADUCT BRIDGE

The steel box girder spherical bearing installation for city viaduct bridge mainly controls installation direction,height,displacement and so on;Before installing the spherical bearing,foundation repetition measure will be conducted and the bearing top plate must be welded to steel box girder floor.This welding adopts metal arc welding method and conducts thermal pretreatment on the condition that temperature is not below 200 ℃ before welding.The steel wedge pad is used in the installation of spherical bearing to level the four corners of bearing plate.As for the grouting of spherical bearing,the foundation bolt holes will be grouted firstly,and then the reserved grouting layer on the bearing underside will be grouted after 24 hours to achieve strength.At the last,the four angle steel wedge pad will be demolished and the epoxy mortar will be used to fill in the pad location.After unloading steel box girder,welding base plate and bottom plate of steel box girder will be welded.After welding,temporary interconnectors will be unloaded and the dust cover will be installed.The allowable deviation of bearing elevation is controlled within ±3 mm,the allowable deviation of bearing shift is controlled within 2 mm.