高寒地区某RCC重力坝施工期温控措施研究

摘要

In this paper, taking a RCC gravity dam of the middle reaches of the Yarlung Zangbo River in Tibet for an example, the numerical and distribution regularities of No. 9 overflow section's temperature and thermal stress field were analyzed and determined the temperature control standard accordingly. Then, analysis of different temperature control measures and the optimum measures were obtained. The results show that the pouring temperatures are 12℃, 16℃ and 20℃ in different constrained areas and distance between cooling water pipes are 1.5 m×1.5 m. A water cooling time is 25 d and temperature is 10℃. 5 cm insulation boards are used in the low temperature season. The temperature field and the stress field of roller compacted concrete dam can satisfy the requirement of temperature control by the recommended measures which has a certain reference value for similar engineering construction in cold highland area.%以西藏雅鲁藏布江中游某碾压混凝土重力坝为例，采用三维有限元法仿真分析其9＃溢流坝段在不同温控措施下的温度场与温度应力场，确定坝体温度控制标准，并对不同温控措施进行敏感性分析。结果表明，最佳温控措施为：强约束区、弱约束区、自由区的浇筑温度分别为12、16、20℃；冷却水管间距1．5 m×1．5 m，一期通水25 d，水温10℃；低温季节覆盖厚5 cm的保温板。在推荐温控措施下，该碾压混凝土坝的温度场及温度应力场能够满足温控要求。