中文摘要：

该文针对混凝土坝孔口结构尺寸相对很小的问题,引入有限元子模型法,解决了子模型切割边界的边值问题,同时提出了减小子模型法存在时间域和空间域离散误差的方法,实现了混凝土坝孔口结构的精确仿真。在此研究基础上,依托某碾压混凝土坝工程,对大坝孔口结构进行了施工期温度场和应力场的仿真计算,重点分析了泄流中孔结构施工期温度和应力的变化及分布规律。研究表明,孔口混凝土在施工早期（10～30d）出现较大拉应力,最大拉应力出现在浇筑后的第一个冬季。子模型法为研究大坝孔口结构的温度场和应力场提供了有效的途径。

英文摘要：

In view of the orifice structure which was much smaller than the dam, the sub-model method was introduced, the problem of cut boundary value was solved, and the method for reducing error of the time and space domain was put forward. Then the accurate simulation of the orifice structure of concrete dam was achieved. Based on the method and a RCCD project, the simulation of the temperature and stress field was carried out, and the variation and distribution of temperature and stress of a typical orifice structure were analyzed in detail. The results showed that the large tensile stress occurred at early age （10-30 d）, and the maximum appeared in the first winter. In addition, the sub-model method can provide an effective way for studying the temperature and stress field of dam orifice structure.