摘要
平潭海峡公铁两用大桥FPZQ-3标段的3座通航孔桥均为双塔钢桁混合梁斜拉桥,桥塔墩均采用圆端哑铃形高桩承台,承台施工采用集主体防撞结构与施工围堰一体的防撞箱围堰结构(由双壁吊箱围堰、防撞梁及联结系组成),将永久结构与施工结构有效结合。防撞箱围堰采用工厂整体制造、整体吊装工艺施工,以实现围堰高精度制造与吊装;围堰下沉采用多台连续千斤顶液压数控整体下放技术,并采用数控液压多点同步下放系统及多层水平限位装置,以克服波流力大、潮位变化大等不利影响,实现围堰自动化下放施工;围堰采用分区封底、系梁区无封底工艺施工,承台混凝土分两层、三次施工,以解决围堰抗浮、抗沉难题。该桥通航孔桥6个桥塔墩承台均已施工完成,结果均满足要求。
T he 3 navigable span bridges of C ontract FPZQ-3 of the Pingtan Straits Rail-cum -Road Bridge are all the double-pylon steel tru ss hybrid girder cable-stayed bridges. T he pile caps ofthe pylon piers of the bridges w ere designed into the elevated pile caps of round-ended dum bbellshape and w ere constructed, using the anti-collision box cofferdam structures （com posed of thedouble-w all boxed cofferdam s, anti-collision beam s and bracing system s） integrating the m ain anticollisionstructures and the construction cofferdam s and as a consequence, the perm anent structuresof the bridge w ere eventually effectively com bined w ith the construction structures. T he anticollisionbox cofferdam s w ere m anufactured integrally in the w orkshop and lifted and installed integrallyin the field in order to realize the highly accurate m anufacturing and installation of the cofferdams. T he m ultiple sets of the continuous jacks and the num erical control hydraulic techniquew ere used to integrally low er the cofferdam s down to the river and the m ulti-point and synchronizedlow ering system of the num erical control hydraulic and the m ulti-level horizontal lim it devicesw ere used as well to get over the adverse influences of the great wave current forces and tide changesand to realize the autom atic low ering of the cofferdam s. A fter the cofferdam s w ere sunk downin place, the bases of the cofferdam s w ere sealed in areas and in the areas of the tie beam s, theconstruction of the base sealing w as not needed. T he concrete for the pile caps was cast in tw o layersand three tim es in order to resolve the problem s of the buoyancy and uplift of the cofferdam s.T he construction of the pile caps of the total 6 pylon piers of the navigable span bridges was com-pleted sm oothly and the results of the construction could m eet the requirem ents.
出处
《桥梁建设》
EI
CSCD
北大核心
2017年第6期1-6,共6页
Bridge Construction
关键词
跨海大桥
公路铁路两用桥
斜拉桥
承台
防撞箱围堰
施工技术
桥梁施工
sea-crossing bridg e
rail-cum -road bridg e
cable-stayed b ridg e
pile cap
anti-collisionbox cofferdam
construction technique
bridge construction
