黄河揭底冲刷的理论分析

Theoretical study on Ripping up the Bottom in the Yellow River

本文从理论上深入研究了黄河上“揭底冲刷”的现象 ,包括土块的起动流速 ,它的上升运动 ,露出水面的条件 ,以及它的下降和沿纵向运动。通过较详细的力学分析 ,给出了有关临界条件和运动方程及其解。这些结果不仅能解释已经观测到的“揭底冲刷”时的各种现象和资料 ,而且能从更深的层次揭露一些尚未被阐述的机理。本文的研究既强调揭河底时水流与泥沙运动的特点 ,也注重它作为一般泥沙运动的共性 ,从而丰富了泥沙起动、推移等的研究领域。

The theoretical study on phenomena ripping up the bottom' is presented in this paper, including the incipient velocity, ascending movement, the exposed condition from the water surface, descending and longitudinal movement of deposit pieces. Based on the mechanical analysis the critical conditions, the dynamic equations and their solutions have been derived. Not only can various phenomena and field data be described in theory, but also some unknown mechanism is unveiled. Both the general principles of sediment movement and the characteristics of flow and pieces moving during the bottom ripped up are studied to expand the research field of sediment.