高“冷热风干”地区RCC坝仿真计算及温控防裂措施

"冷热风干"恶劣气候条件下RCC坝的温控防裂问题十分复杂,对某RCC坝从施工期到运行期最高挡水坝段坝体温度场和温度徐变应力进行三维有限元仿真计算。计算结果表明,采用浇注温度为16℃、一期和二期冷却、全年保温的整体方案,除个别部位需进一步采取措施外,其他部位均能满足防裂要求。介绍混凝土浇注期间和浇注后期所采用的温控防裂措施,认为采取临时和永久保温措施、管道通水冷却、配合比优化和坝体结构优化是进一步防裂的主要手段。

Simulation computation and temperature control measures for crack-prevention studies on RCC gravity dam in cold hot windy and dry areas

The temperature control measures for crack prevention in the'cold hot windy and dry' climate conditions is a complex problem.In this paper,a three-dimensional finite element simulation of temperature field and stress for a dam section of a certain RCC dam with the highest water level during construction and operation is described.The computational results show that the method that adopts 16°as the construction temperature,cooling in the first and second stage and heat preservation throughout the whole year can meet the crack-prevention demands with several exceptional positions.The temperature control measures for crack prevention in and after the concrete pouring stage are introduced and the temporary and permanent heat preservation,conduit cooling and optimization of mixture ratio and dam structures are regarded as the main measures for further crack prevention.