【摘要】 【目的】辨析降雨和汇流条件下松散堆积体坡面泥沙输移及突增的发展规律。【方法】模拟震后松散堆积体坡面,分别设置3个坡度和5个降雨强度进行了降雨侵蚀试验,设置3个坡度和4个汇流量强度进行了汇流侵蚀试验。【结果】降雨试验15°、25°、30°坡面的开始产沙时间均在2～3min范围内;汇流试验10°、25°、35°坡面的开始产沙时间均在1～2 min范围内;降雨试验15°坡面和汇流试验10°坡面在所有试验工况均未发生泥沙输移突增;降雨试验25°坡面仅当降雨强度大于120 mm/h时,发生了泥沙输移突增,而汇流试验中25°坡面在所有汇流量工况下均发生了输移突增;降雨试验30°坡面和汇流试验35°坡面在所有试验工况也均发生了泥沙输移突增。【结论】相似工况下,震后松散堆积体坡面在汇流条件下的开始产沙时间较降雨条件提前;降雨强度或汇流量越大,泥沙输移突增的变化范围越大、发生次数越多。更多还原

【Abstract】 【Objective】We aimed To analyze the development law of sediment transport and sudden increase of loosely piled slope under rainfall and runoff conditions. 【Method】The loosely piled slope after the earthquake was simulated, and three slopes and five rainfall intensities were set for rainfall condition, three slopes and four flooding intensities were set for runoff condition. 【Result】 The results showed that the time to start sand production of the 15°, 25°, 30° slope in the rainfall condition were all within the range of 2～3 min; the time of the 10°, 25°, 35° slope in the runoff condition were all within 1～2 min; the 15° slope of the rainfall condition and the 10° slope of the runoff condition showed no sudden increase in sediment transport in all intensities conditions; the 25° slope of the rainfall condition only showed sudden increase when the rainfall intensity was greater than 120 mm/h, and the 25° slope in the runoff condition showed sudden increase under all flooding intensities; the 30° slope in the rainfall condition and the 35° slope in the runoff condition showed sudden increase in sediment transport in all intensities conditions. 【Conclusion】 Under similar conditions, the time to start sand production on loosely piled slope under the runoff conditions is earlier than the rainfall conditions. The greater the rainfall intensity or flooding intensity, the more variation of the sediment transport and the more occurrences of the sudden increase.更多还原