无粘性土堤漫顶溃决过程初步研究

通过概化水槽试验针对不同的河道流量、洪水位、筑堤材料和堤防断面形式等条件,系统研究了溃口横向展宽、垂向冲刷及内外江水位变化过程、影响因素及发展规律。因溃决流量过程难以实测,基于堤防溃口附近水面变化的实测资料,采用1维非恒定溃堤水流数学模型精确模拟了溃决流量过程。研究结果表明,溃决流量变化滞后于溃口处水头变化,与溃口横向宽度以及溃口处水头密切相关,且符合侧堰溢流规律。研究成果可以为堤防减灾以及灾害评估提供初步技术依据。

Study on Overtopping Erosion of Non-cohesive Embankment

Based on the flume experiments with different river discharge, embankment materials and cross section sizes, this paper investigated overtopping erosion process of non-cohesive embankment. The flume experiments mainly focused on the horizontal expansion and vertical degradation of the breach as well as water level variation of both the inner river and the outer river. Considering the difficulty of monitoring the variation process of the discharge through the breach, 1-D unsteady flow numerical model was applied to simulate discharge process based on the flume experiments data. The research found that the evolution of the breach discharge lags behind that of the water level above the breach, and that the breach width and the water level above the burst gate are the most important factors affecting the discharge through breach. It is found that discharge variation process through the breach gate is consistent with the flow rule of side weir. The investigation results can provide scientific basis for disaster prevention and evaluation of embankment burst.