关键词: 碾压混凝土, 重力坝, 温控措施, 防裂, 敏感性分析

Abstract: Crack of RCC gravity dam is caused directly by thermal stress. It can be mainly prevented by temperature control, construction measures and structure optimization of the dam. A typical overflow dam section of a hydroproject is taken as an example. On the basis of boundary value conditions and thermodynamic parameters of the concrete of each dam zone, the standard of temperature control for the dam body is determined by calculating the stable temperature field, foundation temperature difference, temperature difference between layers and the temperature difference between the interior and exterior of dam body. In line with the temperature control standard, finite element method is employed to conduct sensitivity analysis on some factors such as surface thermal insulation, concrete placing temperature, cooling of water pipes, design of longitudinal structure joints, placing time and lift height. In consequence, measures of temperature control are optimized. The analysis shows that the temperature control measures can meet the requirement of the temperature and stress field of the dam, and ensure the continuous concrete placement. This research provides scientific basis for dam concrete construction.

Key words: roller compacted concrete(RCC), gravity dam, temperature control measures, crack prevention, sensitivity analysis