Abstract: Based on the operation condition of hydraulic structures built on the overburden layer and the experience in its safety assessment, the points of dam site selection, dam axis selection, layout of structures, the bear capacity of overburden composite foundation, the seepage prevention effect of anti-seepage measures, erosion resistance, seismic liquefaction prevention measures and the characteristics of the stress, deformation and seepage of overburden layer are summarized. Further, the characteristics of the hydraulic structures built on overburden layer and the risks are discussed. Aiming at the risks, the key items in safety assessment are advanced, for reference.

Key words: safety assessment, overburden layer, bearing capacity, creep, seepage failure

摘要： 根据覆盖层上水工建筑物实际运行状况及近年覆盖层上水工建筑物安全评价的实践，总结深覆盖层上水工建筑物坝址选择、坝轴线选择、枢纽布置、覆盖层复合地基的承载能力、各种型式防渗措施的防渗效果、防冲蚀、防地震液化处理措施及覆盖层应力、变形、渗流等特点。探讨覆盖层上水工建筑物的特点及存在的风险，并针对这些风险提出覆盖层上水工建筑物安全评价的关注点，以期在现有已取得巨大成就的基础上，进一步提高覆盖层上水工建筑物的设计、建设与安全评价水平。

关键词: 安全评价, 覆盖层, 承载能力, 徐变, 渗流破坏