摘要
当河道布满布袋莲时,大雨来临会使得布袋莲阻塞桥墩间流水空隙,造成排水不良而危及桥梁安全及造成区域之淹水。本研究利用渠槽试验求得渠槽内覆盖布袋莲之曼宁系数,并利用HEC-RAS模式分析本试验渠槽内覆盖布袋莲对渠槽上游水位抬升之情况。本试验所求得覆盖布袋莲之渠槽曼宁系数随着流速改变,流速范围在0.76～11.65cm/s时其曼宁系数为0.026～0.416,而平均值为0.098。以渠槽试验为基准,当流量为1.91×104cm3/s及布袋莲根系长度13cm时,两者上游水位抬升约差6.46%。由研究得知布袋莲根系愈密集渠道试验与数值模拟所得结果愈接近,而且河道满布袋莲时会致使上游水位抬升。
The Eichhornia Crassipes floating on the surface of flow will result in the increase of friction in the open channel. In this paper, the Manning coefficients of channels covered with Eichhornia Crassipes were determined by model test. It was found that the Manning coefficient varies with the flow velocity and the average value is 0.098 when flow velocity is in the range of 0.76cm/s to 11.65cm/s. The water level elevation due to the Eichhornia Crassipes jam is calculated by using the software HEC-RAS.
出处
《水利学报》
EI
CSCD
北大核心
2005年第9期1127-1132,共6页
Journal of Hydraulic Engineering
关键词
布袋莲
曼宁系数
渠槽
水位
Eichhornia Crassipes
Manning coefficient
open channel
water level elevation
