浅析软基条件下鱼腹式变截面箱梁施工技术

Brief Analysis on Fish-Bellied Variable Cross-Section Box Beam Construction on Soft Foundation

天津中新生态城中生大道上跨蓟运河故道桥梁工程,箱梁与一般的变截面箱梁不同之处为其纵横向均为变截面,外形圆润流畅,但同时给施工带来了很大难度。施工中对于不同深度的淤泥,分别采用了钻孔桩和清淤换填、戗灰等软基处理方法,均有效地控制了基础沉降;现浇鱼鳆式变截面箱梁,采用贝雷架作为模板支架,保证了大体积现浇混凝土所需的稳定性和刚度及线形控制,模板制作、钢筋加工均利用软件辅助设计,很好地控制了施工精度,施工效果良好。

For the bridge striding the old Ji Canal at Zhongsheng Street in Tianjin Zhongxin Eco-city,its box beams are different from other variable cross-section box beams in their longitudinal sections are all variable cross-sections with smooth lines and round shape,which causes difficulties to the construction.For different depths of silts,respective treatments for soft foundation are taken including drilling piles,dredging ＆ replacement,soil mixing and so on,which effectively prevent foundation sinks.For the cast-in-situ fish-bellied variable cross-section box beams,bailey framework are adopted as support,which ensure the stability,rigidity and lineal control for concrete casting,besides,for formwork manufacture and steel processing software are used as aided design.All these measurements ensure construction precision and achieve good effects.