台山核电站反应堆筏基混凝土考虑施工过程的温度场模拟分析

Simulation on temperature field of concrete raft foundation of the Taishan Nuclear Power Plant considering construction process

为准确模拟台山核电站筏基混凝土温度场,在有限元模拟分析筏基混凝土水化温度场时,同时考虑了龄期、温度和施工过程的影响。基于混凝土等效龄期和水化度概念,利用绝热温升曲线,确定了混凝土等效龄期水化度曲线。利用ABAQUS有限元软件模拟筏基温度场,通过HETVAL子程序实现由等效龄期水化度曲线确定的混凝土水化生热率,以此考虑龄期和温度对混凝土水化放热过程的双重影响。根据筏基施工方法及形状特性,采用1/2模型,并结合ABAQUS软件中的模型改变交互功能实现模拟施工过程。结果表明:采用等效龄期水化度,可模拟温度和龄期对水泥水化放热过程的双重影响;采用1/2模型和ABAQUS软件中模型交互功能,可模拟筏基混凝土温度场对称分布并受施工过程影响的特性;考虑施工过程模拟温升起始时刻、模拟最高温度及其对应时刻均与实测值吻合较好。

For accurately simulated temperature field of concrete raft foundation of the Taishan Nuclear Power Plant,finite element analysis( FEA) was used to consider effects of age,temperature and construction process. Based on concepts of equivalent age and hydration degree of concrete,equivalent age-hydration degree curve( EAHDC) was obtained based on adiabatic temperature curve. With subroutine HETVAL of the software ABAQUS to specify hydration exothermic rate according to equivalent age-hydration degree curve,the effects of age and temperature on the hydration exothermic process of cement were considered. According to construction process and geometry of the raft foundation,half model of the raft foundation was adopted,and the model change interaction function( MCIF) of ABAQUS was used to simulate the construction process. Analysis results show: effects of temperature and age on the hydration exothermic process of cement can be simulated by using EAHDC; characteristics of temperature field,such as symmetric distribution and effect by construction process,can be captured by using half model of the raft foundation and MCIF of ABAQUS; simulated values,such as time of initial temperature rise,maximum temperature and its corresponding time,agree well with tested values by considering construction process.