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堤防溃决发展过程及口门形态变化的正确描述是及时科学地对溃口进行封堵并对决口后洪水演进过程准确预测的重要依据.考虑到堤防漫顶溃决过程与溃决时河道水力条件、堤防型式、材料组成等因素有关,就外江河道存在水流流动的无黏性土堤溃决溃口的发展过程及口门形态的变化规律进行了水槽试验探索.研究结果发现,河道洪水位或内外江水位差是影响溃口展宽发展的最重要因素.河道洪水流量在堤防溃决初期对溃口的发展影响不大,但溃口的最终宽度和深度随洪水流量的增大而增大.对于试验中采用的无黏性土堤材料,颗粒越粗,漫顶溃决初期溃口发展越快,稳定后的溃口最终宽度却越小.另外,试验还给出了无黏性土堤漫顶溃决溃口的最终形态,如内外江侧溃口宽度比、溃口顶部与底部宽度比以及溃口深度与宽度比等.
The correct description of the embankment collapse process and the change of the shape of the gate is an important basis for timely and scientifically blocking the breach and accurately predicting the evolution of the flood after the breach. Considering the sudden collapse process of the embankment and the hydraulic conditions of the river during the collapse, , Material composition and other factors related to the water flow in the outer river of non-cohesive earth bank collapse of the development process and changes in the morphology of the mouth of the tank test to explore the results show that the river flood level or the difference between the water level inside and outside the river Is the most important factor that affects the development of breachs.The discharge of flood in the river has little effect on the development of breach at the beginning of dike collapse, but the final width and depth of breach increase with the increase of flood flow rate.For the non-stick In addition, the final shape of the non-cohesive soil embankment is also given in the experiment, such as the internal and external river Side breach width ratio, breach top and bottom width ratio and breach depth and width ratio.