【作者】 荆圆圆； 黄小利； 郭志学； 彭清娥； 黄尔；

【Author】 JING Yuanyuan;HUANG Xiaoli;GUO Zhixue;PENG Qing’e;HUANG Er;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University;

【机构】 四川大学水力学与山区河流开发保护国家重点实验室；

【摘要】 山洪暴发时河道输沙强烈,陡坡河道高强度泥沙输移遇到下游河道比降变缓或其他因素导致输沙能力降低时,上游来沙将快速集中淤积,形成淤积锋面。由于泥沙淤积调缓了淤积前锋部位局部的河床比降,河段挟沙能力降低,上游来沙将进一步淤积,该淤积现象快速向上游传播。在淤积锋面泥沙落淤的同时,因水流动力条件降低,淤积前锋部位将产生水跃现象,受床面淤积及水跃共同作用,陡坡强输沙河道在输沙强度降低处将出现水位异常激增的现象,并伴随着河床淤积上延向上游传播。由这类泥沙淤积导致水位激增而引发的灾害,被称为泥沙的附加致灾作用。本文从泥沙淤积作用锋面位置处的受力平衡出发,在交界锋面泥沙处于临界输移状态的假设基础上,根据动量平衡原理,推导了由泥沙附加致灾作用引起的激增水深的计算方法,并采用沙莫夫输沙公式对公式进行了完善,得到了较好的计算陡坡强输沙河道激增水深的计算公式。通过实测水槽数据对计算方法进行了验证,取得了较好的验证效果。更多还原

【Abstract】 During the flash floods,the river sedimentation is strong.If the downstream river in the steep slope reaches is slow down or other factors lead to the decrease of the sediment transport capacity,the upstream sand will rapidly deposit and form deposition front.As the siltation of the sediment slows down the local riverbed, the sediment carrying capacity of the river is reduced,and the upstream sediment will be further deposited.The siltation can propagate rapidly upstream.Due to reduced hydrodynamic conditions in the deposition of frontal sediment,it will produce water jump phenomenon.By the bed sedimentation and water jump together,the phenomenon of abnormal surge of water level will occur at the decrease of sediment transport intensity.and accompanied by the deposition of riverbed up to the upstream.It is known as the additional disaster effect of sediment.Based on the assumption of the balance of sediment in the frontal surface of sediment sedimentation and the assumption of the critical sediment in the boundary.The calculation of the surge depth caused by the additional disaster effect is deduced according to the momentum balance principle the formula and is improved by using Shamov’s sediment transport formula.The formula for calculating the depth of the steep slope is obtained.The calculation method is verified by the measured sink data,and good validation results have been achieved.更多还原