Impact Of High-Pile Wharf On Flow Field And Topography

Structures combining trestle and high-pile pier have been widely used in open water ports. It is of great importance for pier layout to study on characteristics of flow field and of seabed scouring and depositing around pier group before and after being built.The article has studied on characteristics of flow field around pile group by changing its length L, width B, pile diameter D, layout, and flow hydrodynamic conditions. Stresses have been laid on analyses of influencing extension and degree on flow field by all factors, especially in condition of various angles between wharf apron line and flow direction. According to results of model test, characteristics of flow field around pier group have been summarized, and reasonable suggestions for wharf engineering design have thus been put forward.After being built of high-pile wharf, flow field and seabed scouring and depositing feature around it have both changed. Because the local scouring and depositing feature is the results of interaction of pile group with flow sediment movement, it has been studied in condition of various layout and inflow angle ? through movable bed test on the ground of fixed bed flow test. Reasonable layout has been explored to avoid scouring and depositing feature against wharf front depth maintenance and project itself stability, to improve utilization efficiency, and to reduce maintenance cost.It has been found that wharf pile group layout has great influence on the characteristics of nearby flow field and seabed scouring and depositing feature. Increase of wharf pile group width leads to raising blocking flow area and total resistance, and therefore to strengthen flow and seabed change. When inflow angle increases to some extent, depositing volume biases toward behind the wharf. So pile group resistance should be reduced as possible in design of wharf. In addition, according to harbor specification, inflow angle less than±5°is permitted between wharf apron line and main flow direction. It has been shown that inflow angle less than 0°can lead to deposition in some extent in front of wharf, so positive inflow angle can effectively promote water depth in front of wharf and other maintenance condition.