多因素作用下河道崩岸过程试验与数值模拟研究

Experimental and numerical simulation of bank collapse process under multi factors

崩岸的影响因素众多,成因复杂,现有的研究大多聚焦单一因子,且各因素之间的相互关系不明晰。结合室内水槽试验和数值计算,分析了多因素作用下崩岸的过程,揭示了岸壁失稳的力学机制。分析结果表明,剪切、张拉和绕轴破坏以及基质吸力降低引起的土体脱落是侧向流冲刷岸壁崩塌的主要类型,相对水深(岸壁高度/近岸水深)的降低导致岸壁破坏类型从绕轴破坏转变为剪切破坏,渗流与侧向流共同作用会大大加快岸壁坍塌过程。

There are many factors affecting bank collapse, and the causes are complex. Most of the existing studies focus on a single factor, and the relationship between the factors is unclear. Combined with laboratory flume test and numerical calculation, the process of bank collapse under the action of multiple factors is analyzed, and the mechanical mechanism of bank instability is revealed. The analysis results show that shear, tension and axial failure as well as soil shedding caused by the reduction of matrix suction are the main types of bank collapse caused by lateral flow scouring. The reduction of relative water depth(bank height/near shore water depth) causes the bank failure type to change from axial failure to shear failure. The joint action of seepage and lateral flow will greatly accelerate the bank collapse process.