通州湾港区一港池回淤对策

通州湾港区一港池建在辐射沙洲南缘腰沙高滩上,港池航道开挖后的回淤问题是工程设计关注的焦点。设计时通过研究工程海域潮流、波浪、泥沙、底质等自然特征,分析影响回淤的主要因素,从挡沙堤平面布置、备淤深度确定、维护疏浚、船舶吃水控制等方面提出一系列针对性措施。研究认为:通州湾港区一港池建在粉砂质浅滩上,港池航道开挖必会出现回淤,但一港池坐北朝南,受掩护情况较好,产生骤淤的几率较小。先期可通过港池航道试挖、预留足够备淤水深、配备高效率的挖泥船、控制船舶吃水来应对回淤问题,将来可结合回淤观测成果、维护难易程度、船舶进出港影响,综合考虑是否建设挡沙堤。

Countermeasures against siltation of No.1 harbor basin of Tongzhou Bay port area

The No.1 harbor basin of the Tongzhou Bay port area is built at Yaosha,which is on the southern edge of the radiation sandbar,and siltation after channel excavation of the harbor basin is the focus of engineering design.In design,by studying the natural features of the engineering sea areas such as tidal current,wave,sediment,and substrate,and analyzing primary factors affecting siltation,we propose some countermeasures,such as layout of sand barriers,determination of the depth reserved for siltation,maintenance dredging,and draft control.The research reveals that since the No.1 harbor basin is built on a shallow silty beach,channel excavation of the harbor basin will result in siltation.However,the No.1 harbor basin has its entrance facing south and is well sheltered,so there is only a low risk of sudden sedimentation.In the first stage,we can cope with siltation by trial dredging in the harbor channel,reserving sufficient water depth for siltation,equipping an efficient dredger and controlling draft.In the future,we can consider whether to build a sand barrier or not by combining the results of siltation observation,the difficulty of maintenance and the influence of ships entering and leaving the harbor basin.