丁坝及淹没丁坝冲刷公式研究

针对整治建筑物冲刷问题,依托长江南京以下12.5 m深水航道治理一期工程,研究探讨了普遍冲刷和淹没丁坝冲刷的冲刷规律、主要影响因素、冲刷机理。基于河流动力学基础理论,分别推导了基于起动流速、起动切应力的冲刷深度半经验半理论公式,经非淹没丁坝冲刷实例和淹没丁坝冲刷数模成果验证和率定,效果良好,适用于非淹没丁坝和淹没丁坝冲刷深度计算,从冲刷计算原理看,同样适用于顺坝及护岸冲刷深度计算。对其中有关冲刷深度半经验半理论公式的主要研究成果进行了系统总结。

Calculation formulae for spur dike and submerged spur dike

Based on the implementation of the 12.5 m deep-water channel regulation project (phase I) in the Changjiang river downstream of Nanjing,this paper focuses on the scouring issues of applied regulation structures,studies the regularity,main influence factors and mechanism of general scour as well as scouring around the submerged spur dike,and respectively deduces in line with the fundamental theory of river dynamics the semi-empirical and semi-theoretical formulas for calculation of scouring depth resulting from initial flow velocity and initial shear stress.Based on practical examples of scouring occurred around non-submerged spur dike and the results of numerical scouring modeling for submerged spur dike,these formulas are verified and calibrated with good effects,and they are not only applicable to the calculation of scouring depth around the non-submerged and submerged spur dikes,but also suitable for the calculation of scouring depth developed at longitudinal dike and revetment in view of the fundamental theory of river dynamics.This paper makes a systematic summary of the major study results related to the semi-empirical and semi-theoretical formulas for calculation of scouring depth.