泄洪洞混凝土衬砌温控方案研究

为寻求衬砌混凝土的有效温控防裂措施,结合某泄洪洞混凝土衬砌实际情况,在考虑了混凝土热力学参数随龄期变化、混凝土实际浇筑过程对温度应力影响的基础上,设计不同的温控方案,利用大型有限元软件对泄洪洞衬砌混凝土温度场、温度应力场进行了三维仿真计算.结果表明:衬砌混凝土浇筑完后第2天达到最高温度,第3天表面出现较大的拉应力,混凝...

Research on temperature control option for concrete lining of spillway tunnel

For the purpose of finding out measures to effectively control the temperature and cracking of lined concrete,based on the actual situations of concrete lining of a spillway tunnel,and considering the change of thermodynamic parameters of concrete with its age and the impact of concrete placement process on temperature stress,different temperature control options are designed and three-dimensional simulation calculation is carried out for temperature field and temperature stress field of spillway tunnel lining concrete by use of large finite element software.The results show that on the 2nd day after placement,the lining concrete reaches its maximum temperature,and on the 3rd day large tension stress and cracking appear on the concrete surface;concrete stress increases due to curing by river water after concrete placement;surface insulation makes the decreasing speed of concrete surface temperature slowed down and stress increased slowly,and surface cracking is hard to occur in the early period,so it is a very good method to prevent early surface cracking.