山区河流洪水涨落时双层堤基非稳定渗流数值分析  

Numerical Analysis of Unstable Seepage in Double Layer Dyke Foundation During Flood Fluctuations in Mountainous Rivers

作　　者：尹伟强 吴涛 YIN Wei-qiang;WU Tao(Ganzhou Institute of Water Resources and Electric Power Investigation and Design,Ganzhou 341000,China;China Railway Water Conservancy&Hydropower Planning and Design Group,Nanchang 330029,China)

机构地区：[1]赣州市水利电力勘测设计研究院,江西赣州341000 [2]中铁水利水电规划设计集团有限公司,江西南昌330029

出　　处：《水电能源科学》2024年第9期190-193,198,共5页Water Resources and Power

摘　　要：长期以来堤基渗流稳定问题一直是堤防设计的关键难点,尤其山区河流洪水涨落快、历时短,难以形成稳定渗流场,因而必须考虑洪水涨落的非稳定渗流场以求取最经济可靠的渗控措施。基于非饱和渗流理论,研究山区河流洪水涨落时堤防非稳定渗流浸湿过程及渗流特性,并与稳态渗流形成对比。结果表明,非稳定渗流场的浸润线前端表现为内凹,存在滞后性,由于双层堤基相对弱透水覆盖层的存在,堤身内浸湿距离较短,浸润前锋尚未到达坡脚;迎水坡典型部位的水力坡降明显大于稳定渗流,采用稳定渗流分析山区河流双层堤基渗透稳定时,所得结果对堤防更为不利。The stability of seepage in dyke foundations has long been a key difficulty in dyke design,especially in mountainous rivers where floods fluctuate rapidly and have a short duration,making it difficult to form a stable seepage field.Therefore,it is necessary to consider the unstable seepage field of flood fluctuations in order to obtain the most economical and reliable seepage control measures.Based on the theory of unsaturated seepage,this paper studied the wetting process and seepage characteristics of unstable seepage in embankments during flood fluctuations in mountainous rivers,and compared with steady-state seepage.The results show that the front end of the infiltration line in the unstable seepage field is concave with hysteresis.Due to the relatively weak permeable cover layer of the double layer dyke foundation,the wetting distance inside the dyke is short,and the infiltration front has not yet reached the foot of the slope;The hydraulic gradient of typical parts of the upstream slope is significantly greater than that of stable seepage.When steady-state seepage is used to analyze the seepage stability of double layer dyke foundations in mountainous rivers,the obtained results are more unfavorable for embankments.

关 键 词：山区河流 洪水涨落 双层堤基 非饱和土体 稳定渗流 

分 类 号：TV871[水利工程—水利水电工程] TV223.6