郁江特大桥主桥为（36＋96＋228＋96＋36） m 双塔双索面钢桁梁斜拉桥，两桥塔墩基础为深水基础，采用双壁钢围堰施工，钢围堰平面尺寸为40．6 m ×27．4 m ×20．2 m ，封底厚度仅3．5 m 。施工过程中采用桩基钢护筒内外均设抗剪箍解决抗浮问题。为确保抗剪箍的作用效果，提高水下混凝土的施工质量，水下混凝土的封底施工采用优化水下混凝土配合比、一次拔球和安装单向堵头等关键施工措施，一次成功完成706 m2封底净面积的水下混凝土灌注，确保了钢围堰的施工质量。%The main bridge of Yujiang River Bridge is a two-pylon steel truss girder cable-stayed bridge with span arrangement of (36 + 96 + 228 + 96 + 36) m and with double cable planes . The two pylons are based on deepwater foundations that are constructed by using double-wall steel cofferdams .The cofferdam measures 40 .6 m × 27 .4 m ,20 .2 m in height ,but the thickness of the bottom sealing layer is only 3 .5 m .During the construction process ,shear stirrups were installed both inside and outside the steel casings of the piles ,with the intension of counteracting the buoy-ancy of the cofferdam .To ensure the efficiency of the shear stirrups and improve the construction quality of the tremie concrete ,a series of critical construction measures were taken in the casting of the bottom sealing concrete ,such as optimizing the mixing proportion of the tremie concrete ,one-time ball drawing and installing one-way plugs .A net area of 706 m 2 of tremie concrete was suc-cessfully cast by one-time operation and the construction quality was ensured .
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