深水涌浪条件下跨海桥梁大型打桩船施工关键技术

Key Construction Technology of Large Pile Driver for Cross-sea Bridge Under Deep Water and Swell Condition

针对深水涌浪条件下跨海桥梁桩基施工所面临的难题,以主墩65m水深的巴西萨尔瓦多跨海大桥为依托项目,研究了深水钻孔灌注桩所允许的垂直度偏差,分析了钢护筒施工要求的垂直度标准,确定了打桩船纵横摇限值为0.25°;基于Sesam势流软件分析了船舶在不同浪向、波高和周期下的运动响应,提出了80,90,102m大型打桩船的施工窗口期;开展项目海域的波浪后报分析,获取项目多年逐墩逐月的波浪数据,后报出船舶的施工窗口频率,辅助决策了大型打桩船选型和施工调度,确保了深水涌浪跨海大桥项目施工的可靠性和经济性。

It is very difficult to drive steel casing of cross-sea bridge under deep water and swell condition.Based on the Brazil Salvador Cross-sea Bridge with 65m water depth of the main pier,allowable verticality of bored pile is studied to confirm the allowable deviation of steel casing.Assuming the same verticality of steel casing and vessel,the allowable extreme value of roll and pitch is found as 0.25°.Potential flow Sesam software developed by DNV is applied to analyze the dynamic response of three typical large driving vessels with 80,90,102m waterline length in different wave conditions.The wave hindcast,pier by pier,and month by month,is analyzed on Brazil Salvador Bridge construction area.The constructable window periods of three large driving vessels are calculated to help the project make reasonable decision.It ensures the reliability and economy of the construction of cross-sea bridge project under deep water and swell condition.