洞庭湖区堤防垂直防渗模型研究

根据洞庭湖区堤防工程地质、地形特性，建立了多元结构堤基垂直防渗概化模型，并按照优化思想，采用渗流有限元法，对垂直防渗墙在砂卵石、相对不透水堤基中的贯入深度和堤内最大渗透坡降的位置、大小的关系做了系统地分析研 究。再根据有限元计算结果，全面地评价了两种型式防渗墙的防渗效果，提出了临界最优贯入深度的概念。最后，将有限元法应用到大东口电排高喷防渗墙工程中，实际工程的安全运营表明了研究结果的正确性和实用性。

Study of vertical cutoff wall model for levees in Dongting Lake region

Based on the characteristics of geology and landform of the levees in the Dongting Lake region, a generalized model of vertical cutoff wall on multi-structure levee foundation has been established; then following the optimization concept and using the seepage FEM, a systematic study of the relationship between the vertical cutoff wall penetration in sand and gravel layer or the relative impermeable layer and the maximal seepage gradient inside levee is carried out. Then based on the FEM results, the comprehensive and objective estimation about the effect of anti-seepage of the two types is introduced. And a definition called critical optimization penetration is put forward for the first time. Finally, seepage FEM is applied to high pressure grouting cutoff wall project in Dadongkou Electric Drainage Project; the safe operation of real project shows that the analysis of this paper is right and practical.