Abstract: Building a dam on the overburden, excavation of overburden and backfill are always effective measures to reduce dam settlement. Depth of overburden excavation has great influence on dam settlement. Combined with a case study, the paper presented the schemes with different excavation depths. Based on material parameters in test, finite element calculation and comparison of calculation results were carried out, worthy reference for schemes selection.

Key words: overburden, sluice bottom plate, settlement, excavation depth, Duncan-Chang E-B model

摘要： 在覆盖层上建坝，为减小坝体沉降，常对覆盖层进行开挖和回填。覆盖层开挖回填深度对坝体沉降变形影响较大。以某闸坝工程为例，拟定不同的开挖深度方案，根据室内试验参数，分别进行有限元计算，并对比分析计算结果，为开挖深度方案选择提供参考性意见。

关键词: 覆盖层, 闸底板, 沉降, 开挖深度, 邓肯-张E-B模型