基于温控仿真的RCC重力坝施工期开裂风险分析

Cracking Risk Analysis of Roller Compacted Concrete Gravity Dam in Construction Period Based on Temperature Control Simulation

温度荷载是使大体积混凝土在施工期间产生裂缝的主要因素。为对大体积混凝土开展施工期开裂风险分析,以某碾压混凝土(RCC)重力坝为例,在对其温控措施进行仿真分析的基础上,利用结构的可靠度理论,将大体积混凝土开裂的影响因素作为变量,运用响应面法构建极限状态功能函数,利用Monte-Carlo法得到该重力坝施工期的开裂风险和可靠度。分析成果表明:推荐温控措施合理;开裂风险概率和可靠度指标计算成果能够反映内部特征点的开裂风险高于外部、一期冷却末期出现最大开裂风险的特点,该方法可用于施工期的混凝土开裂风险评价。

Temperature load is the main cause of cracks in mass concrete in construction period.The cracking risk probability and reliability of a roller compacted concrete(RCC)gravity dam are calculated by Monte-Carlo method with factors affecting the cracks in mass concrete as random variables in establishing the limit state function by response surface method based on simulation of temperature control measures.Results demonstrate that the recommended temperature control measures are reasonable.Calculation results of cracking risk probability and reliability reflect that the cracking risks of feature points inside the RCC dam are higher than those exterior to the dam,and the maximum cracking risk appears in the end of the first-phase cooling stage.