深冲积层上高面板堆石坝运行期渗流特性仿真研究

Simulation Study on Seepage Characteristics of High CFRD on Deep Alluvium Layer during Operation Period

渗流控制是深冲积层上修建高面板堆石坝需要研究的关键技术问题,以某高面板堆石坝工程为对象,考虑坝体结构、渗控体系、深冲积层以及基岩分布等要素,建立三维有限元计算模型,然后采用改进节点虚流量法,进行正常运行期的坝区三维渗流特性仿真计算与分析。结果表明,混凝土面板、趾板、防渗墙及灌浆帷幕形成的空间封闭防渗体系能够有效控制坝区渗漏,保证坝体及坝基的渗透稳定,但尽管如此,深冲积层的坝基和地质条件复杂的两岸坝肩的渗流控制难度较大,对防渗墙和灌浆帷幕的要求较高,在大坝渗控设计和施工时予以重点关注。

One of the key technique problems of high concrete faced rock-fill dam （CFRD） which is built on deep alluvium layer is seepage control. Taking a high CFRD project as study case, the 3D FEM model is firstly built in view of the factors of dam structure, seepage control system, deep alluvium layer and bedrock distribution, and then, the 3D seepage characteristics of dam are simulated and analyzed by using improved node virtual flow method. The results show that the closed impervious system of dam, which is combined by concrete face, toe slab, concrete cut off walt and grouting curtain, can effectively control dam leakage and ensure seepage stability of dana. However, there is great difficulty in seepage control when the dam founds on deep alluvium layer and the geological conditions of dam abutment are complex, therefore, the concrete cut off wall and grouting curtain should be paid more attention in seepage control design and construction of dam.