依托2022年度“长江口二号”古船整体迁移与保护项目,针对1#船坞坞墙背后减压排水部分失效的现状,模拟打捞船进、出坞的短期工况及后期永久使用工况.分析计算坞墙及桩基的位移及受力情况,发现重新启用1#船坞时,荷载增量主要来自坞墙背后无法疏干的地下水水压力.计算表明:①坞墙原桩基结构设计受力合理,减压排水系统的设置能够大幅减小坞墙后的水压力;②在打捞船进、出坞的短期工况中,墙后新增水压力较小,桩基的位移与承载力均未超限;③在长期工况中,若减压排水系统完全失效,墙后新增水压力较大,斜桩的抗拔承载力可能超限.因此,为保障船坞长期使用的安全性与耐久性并减轻对周边环境的影响,应结合今后对船坞再利用的情况,采取合理措施保障坞墙壁后排水通道畅通,使地下水位维持在横梁底面以下标高.

Based on the overall relocation and protection project of “Yangtze River Estuary II” ancient ship in 2022, aimed at the failure of the decompression drainage behind the dock wall of No. 1 Shipyard, the short-term working conditions of the salvage ship in and out of the dock and the permanent working conditions in the later period are simulated. The displacement and stress of the dock wall and pile foundation are analyzed and calculated. It is found that when Dock No. 1 is re-used, the load increment mainly comes from the groundwater pressure behind the dock wall that cannot be drained. The calculation shows that the original pile foundation structure of the dock wall has a reasonable design force, and the installation of a decompression drainage system can greatly reduce the water pressure behind the dock wall. In the short-term working conditions of the salvage ship entering and leaving the dock, the water pressure behind the newly added wall is small, and the displacement and bearing capacity of the pile foundation are not exceeded. In the long-term working condition, if the decompression drainage system completely fails and the new water pressure behind the wall is large, the uplift bearing capacity of the inclined pile may exceed the limit. Therefore, in order to ensure the long-term safety and durability of the dock and reduce the impact on the surrounding environment, reasonable measures should be taken to ensure that the drainage channel behind the dock wall is smooth and the groundwater level is maintained below the bottom of the lower beam in combination with the situation of dock reuse in the future.