基于ANSYS的CRTSⅢ型轨道底座板混凝土施工裂缝分析

Construction crack analysis for the concrete of CRTSⅢ slab track roadbed based on ANSYS

针对高寒地区薄壁混凝土施工过程中受环境温度和湿度影响而产生早期裂缝的现象,基于大型有限元软件ANSYS,建立模型分析底座板混凝土浇筑过程其内部温度和湿度随环境条件的变化以及由此产生的应力和位移。研究结果表明:不同环境条件对混凝土影响有很大不同;混凝土内表温差越大,内部产生的应力也越大,且夜晚的内表温差较白天的大;环境湿度越小,混凝土表面的水分散失的越快,而底部混凝土水分散失得相对较慢,使得混凝土内表湿度相差越大。由此产生的内部拉应力越大,很容易产生早期裂缝。因此,在混凝土施工过程中很有必要采取保温保湿措施以控制早期裂缝的发展。

The phenomenon of early cracks caused by the influence of temperature and humidity during the construction of thin-walled concrete in alpine regions is particularly prominent.Based on ANSYS,this paper analyzed the change of temperature and humidity inside the concrete and the stress and displacement due to environment temperature and humidity changing during the concrete pouring process.The results show that the effects on concrete of different environmental conditions are very different.The greater the temperature difference between interior and surface of the concrete,the greater the internal stress,and the temperature difference of the internal surface at night is larger than that of the day.The smaller the environmental humidity,the faster the water loss on the surface of the concrete,and the water of bottom concrete disperse relatively slow,which resulting the greater humidity grade in the concrete.All of the above will result in internal tensile stress in the concrete,and the early cracks generate.Therefore,it is necessary to take measures to keep heat and moisture to control the development of early cracks during concrete construction.