强沿岸输沙海岸港口建设对岸线变迁影响数值模拟研究

Numerical modeling of shoreline evolution after harbor construction at strong longshore sediment transport coast

以非洲西海岸塞拉利昂码头工程为例,基于一线模型理论模拟计算了港址沿岸输沙率,以及码头拦沙堤建成后的上、下游岸线长期变迁。根据模拟成果,工程海域沿岸输沙强度极大,年总输沙率可达94.5万~97.1万m^3/a,净输沙率达71.1万~73.6万m^3/a,码头拦沙堤拦截了自南向北的沿岸输沙,堤身南侧形成明显堆积,堤身北侧形成侵蚀。根据与西非海岸类似港口工程实际经验对比,文中数值模拟所得成果是合理的。

Using the coal port of Sierra Leone at western Africa as an example,the longshore sediment transport rates(LSTR),as well as the shoreline evolution of the upper and lower reaches after the completion of wharf sediment breakwater were modeled based on the one-line model.According to the modeling results,the LSTR at the study coast is extremely large,the annual total LSTR is in the range of94.5伊104to97.1伊104m3/a,and the net LSTR is around71.1伊104to73.6伊104m3/a.The wharf sediment breakwater intercepted the longshore sediment transport from the south to the north,which forms the shoreline deposition at the south side and the shoreline erosion at the northern side.Comparisons with actual experience of the similar harbor projects in West Africa,it is proved that the model results are reasonable.