凌汛期堤防漫顶溃口破坏规律断面模型试验Ⅰ:黏性土堤

Cross-section model test for embankment overtopping breach patterns during ice flood seasonⅠ:Cohesive soil embankments

凌汛期河道存在大量冰凌,导致河流壅塞、水位上涨,对堤防安全造成了严重隐患。为了探究凌汛期黏性土堤的漫顶溃口破坏规律,建立了室内水槽物理模型,模拟了冰凌条件下的堤防漫顶破坏,通过改变堤身含水率和河道流量,分析了冰凌条件下溃堤时的溃口破坏形式、溃口发展过程和水位变化过程。结果表明:溃堤过程中冰凌挤压对堤体的破坏作用明显,堤身含水率和河道流量对溃堤过程有显著的影响;与洪水条件相比,冰凌条件下溃堤时溃口前期发展较为缓慢,而中、后期较为强烈;冰凌条件下的堤前水位峰值要高于洪水条件。

The abundant ice in the river during the ice flood season clogs the river course and makes the water level rise,which poses a great threat to the safety of the embankments along the river.In order to investigate the law of overtopping failure of cohesive soil embankments during ice flood season,a physical model of laboratory flumes was established.By changing the water content of embankment body and the flow in the river,the breach patterns,breach development and water level change under ice flood condition were simulated and analyzed.The results show that the ice extrusion plays an important role in the failure process of the embankment body.The water content of the dike and the flow of the river have significant effects on the process of the embankment failure.Compared with the flood condition,the development of the failure under ice flood condition is relatively slow in the early stage,but more intense in the middle and late stage.Furthermore,the peak water level in front of the dike under ice condition is higher than that under flood condition.