沉湖汉江特大桥主桥连续刚构施工技术

沉湖汉江特大桥主桥为(102+168+102)m连续刚构桥,上部结构为单箱单室、变高度、变截面梁,下部结构采用双墩薄壁圆端形桥墩、钻孔灌注桩基础.主桥桩基采用旋转钻机成孔,承台采用钢板桩围堰法施工；上部结构0号块采用落地式支架法施工,其余节段采用菱形挂篮悬臂浇筑施工,在中跨合龙口设置4 000 kN的水平顶推力,完成中跨合龙.为了保证施工质量及安全,使该桥的实际状态最大限度地趋近设计状态,通过施工监控,使中跨合龙口精度满足规范要求、成桥线形与设计吻合.

Construction Techniques for Continuous Rigid Frame of Main Bridge of Chenhu Hanjiang River Bridge

The main bridge of Chenhu Hanjiang River Bridge is a continuous rigid frame bridge with span arrangement(102+168+102) m.The superstructure of the bridge is the single-cell single-box girder with variable depth and variable section and the substructure has round ended thin-wall twin piers supported on bored pile foundations.The holes of the bored piles for the main bridge were bored by the rotary boring machines and the pile caps were constructed in the steel sheet pile cofferdams.The segments No.0 of the superstructure were constructed on the scaffolding while the rest of the segments were cantileveredly cast in situ by the diamond-shape form travelers.At the closure gap at the central span,the 4 000 kN horizontal pushing force was applied to fulfill the closure of the span.To ensure the construction quality and safety and to keep the actual status of the bridge to approach the design status to the maximum extent,the closure precision of the closure gap was made to accord with the requirements in the codes and the geometric shape of the completed bridge was made to meet the design status through the construction monitoring and control.