基于潮汐影响的人工岛内河常水位确定

Determination of inland river constant water level in artificial island based on tidal influence

针对人工岛四周砂质堤透水性强、内河水位受外海潮位影响显著的问题,为避免人工引排须选定合理的人工岛内河常水位。通过建立非稳定渗流模型,研究渗流场与渗流量随潮位变化的关系。选取近海典型潮位,采用分段求和法计算在一个潮汐周期内各种拟定的内河水位的净渗流量。对应净渗流量为零的内河水位即为最佳河道常水位,该水位为确定内河河道规模及岛内吹填地面高程提供了基础。

Aiming at the strong permeability of sandy embankment around the artificial island and the obvious influence of sea tide level on the water level of the inner river,a reasonable water level of the inner river on the artificial island should be selected to avoid artificial drainage.Through the establishment of unsteady seepage model,the relationship between seepage field and seepage flow changes with tidal level is studied.The typical tide level of the offshore sea is selected,and the net seepage discharge of various proposed inland river levels within a tidal cycle is calculated by subsection summation method.The water level corresponding to zero net seepage discharge is the optimal normal water level of the river channel,which provides a basis for determination of the scale of the inland river channel and the elevation of dredging ground in the island.