土性参数变异性较大是堤防工程风险管理面临的问题之一。在分析土体渗透系数空间变异性的基础上,通过随机数值模拟研究了堤防渗流场统计特征和堤基渗透稳定性。将土体渗透系数作为随机场,采用转动带法进行随机抽样模拟,通过蒙特卡罗方法分析渗流场分布,并计算堤基渗透失稳概率,结合堤防工程进行了计算分析。结果表明,渗透系数的空间变异性对渗流场有较大影响,随渗透系数和临界比降的变异性增大,容易造成局部渗流集中,堤基渗透失稳概率增大。
Abstract
The significant spatial variability of soil property is a difficult problem for risk management of levee. On the basis of analyzing the spatial variability of soil permeability, the statistical characteristic of seepage field and seepage stability of levee foundation is studied by stochastic numerical method. Random field model is adopted for soil permeability, and the turning bands method is employed to simulate the permeability random field. The distribution of seepage field and probability of seepage failure are evaluated by Monte-Carlo method. The presented approach is applied to a case study. Results imply that the spatial variability of soil permeability has great impact on seepage field; with the increase of variation of permeability and critical gradient, local seepage is highly concentrated, and seepage failure probability of levee foundation also increases.
关键词
堤防渗流 /
渗透系数 /
空间变异性 /
渗透稳定 /
数值模拟
Key words
levee seepage /
permeability /
spatial variability /
seepage stability /
numerical simulation
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基金
国家重点研发计划项目(2017YFC1502606);中央级公益性科研院所基本科研业务费项目(CKSF2017038/YT)
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