| 摘要: |
| [目的]探明地下衬砌混凝土出现裂缝的原因,研究进一步采取综合温控措施防裂的有效性和合理性.[方法]结合工程实际情况,在考虑混凝土热力学参数随混凝土龄期的变化,以及坝体分层浇筑过程对温度应力影响的基础上,利用大型有限元软件对泄洪洞衬砌施工过程中的温度场和温度应力进行了三维仿真计算.[结果]仿真结果给出了衬砌混凝土温度场、温度应力分布及其随时间变化的规律,即于开浇后的第2天达到最大温度值,第3天即开始出现较大拉应力值,而极值出现在中后期.[结论]在混凝土浇筑过程中,应采取降低浇筑温度等措施;在浇筑后的10～28 d温降期间,要对混凝土表面施行流水养护等温控措施,严格各项施工规范. |
| 关键词: 大型泄洪洞 衬砌混凝土 施工期 温度场 温度应力 仿真分析 |
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| Simulation of temperature field and thermal stress of pubugou divertion tunnel during construction |
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| Abstract: |
| 【Objective】 The research discussed the causes leading to the appearance of cracks in the side wall lining concrete of the diversion tunnel,and studied the effectiveness and reasonability of comprehensive temperature measures to prevent cracks.【Method】 Given the actual situation,large scale finite element software was used for spillway lining of the construction temperature,the temperature stress field in the three dimensional simulation.Calculations took into consideration the changing of the concrete thermodynamic parameters with age,and the effect of the dam laying process on temperature stress.【Result】 The simulation results showed temperature,and temperature stress distribution changed over time;namely,the temperature peaked on the second day after pouring,from the third day more stress value began to appear,and the extreme value appeared in the latter part.【Conclusion】 In the concrete pouring,it is necessary to reduce the pouring temperature.During 10 to 28 days after pouring,water conservation measures should be taken to control temperature strictly. |
| Key words: large spillway lining concrete operation period temperature field temperature stress simulation analysis |
