河口航道边抛弃土运动的计算

Numerical simulation of sidecast dredged spoil movement along estuarine waterways

简述边抛疏浚原理和边抛施工的水动力依据,将边抛泥沙作为点源,边抛弃土分为悬沙和浮泥两部分.介绍了悬沙运动基本方程,得到悬沙浓度、水体中悬沙含量随时间、运动距离的变化;对边抛浮泥运动基本方程进行简化处理得到边抛浮泥运动速度、厚度在上层水流、重力、底部摩擦等因素作用下的运动规律.对长江口北槽下段挖槽边抛弃土中悬沙和浮泥进行模拟计算并进行分析,以提高边抛成槽率.

The principle and hydrodynamic basis of sidecast dredging are briefly described. The sidecast spoil is taken as point sources and divided into suspended sediment and fluid mud. The basic equation of motion of suspended sediment is introduced, and the regularity of variation of concentration and quantity of suspended sediment in water bodies with time and distance is obtained. By simplification of the basic equation of sidecast fluid mud, the variations of the moving velocity and thickness of fluid mud are deduced under the actions of the current velocity over the fluid mud surface, gravity, and bed friction. Finally, with sidecast dredging at the lower reach of the North Channel in the Yangtze River Estuary as an example, the suspended sediment and sidecast fluid mud are numerically simulated and analyzed for improvement of the trench formation efficiency of sidecast dredging.