摘要
混凝土面板早期裂缝主要由温度应力引起,准确预测分析混凝土面板的温度场及温度应力变化过程,并研究混凝土面板温度裂缝的开裂过程,是关系到混凝土面板堆石坝安全的关键难题.基于热传导理论和弹性徐变理论,引入了水化度和等效龄期概念,编制了温度场及温度应力计算程序,对比分析了水化度及等效龄期对混凝土面板温度场及温度应力的影响,并进一步研究了混凝土面板温度裂缝的分布情况及扩展过程.研究结果表明:仅考虑水化度影响的模型温度场及温度应力的计算值偏低,而同时考虑等效龄期的影响,即可有效解决此问题.在混凝土面板温降过程中会产生较大的拉应力,从而引起面板开裂.裂缝主要集中在面板底部和中部,且多为水平裂缝,裂缝深度最终可达到面板厚度的75%,严重影响面板的耐久性,因此需做好相应的防护措施.
The early cracks of concrete face are mainly caused by temperature stress.Therefore,it is a key problem related to the safety of concrete face rockfill dam to accurately predict and analyze the temperature field and temperature stress change process of concrete face and study the cracking process of temperature cracks in concrete face.Based on the theory of heat conduction and elastic creep,this paper introduces the concepts of hydration degree and equivalent age,and compiles the calculation program of temperature field and temperature stress.The effects of hydration degree and equivalent age on the temperature field and temperature stress of concrete face are compared and analyzed,and the distribution and expansion process of temperature cracks in the concrete face are studied.The results show that the model that only considers the influence of hydration degree has low calculated values of temperature field and temperature stress,but this problem can be solved effectively by considering the influence of equivalent age at the same time.Large tensile stress will be produced during the temperature drop of concrete face,which will lead to cracking of concrete face.The cracks are mainly concentrated at the bottom and the middle of the face,and most of them are horizontal cracks.The depth of the cracks can eventually reach 75%of the thickness of the face,which seriously affects the durability of the face.So it is necessary to take appropriate protective measures.
作者
李炎隆
卜鹏
张敬华
温立峰
LI Yanlong;BU Peng;ZHANG Jinghua;WEN Lifeng(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xian University of Technology,Xian 710048,China)
出处
《武汉大学学报（工学版）》
CAS
CSCD
北大核心
2019年第11期951-961,共11页
Engineering Journal of Wuhan University
基金
国家优秀青年科学基金项目（编号：51722907）
国家自然科学基金项目（编号：51979224）
关键词
混凝土面板
水化度
等效龄期
温度裂缝
扩展有限元
concrete face
hydration degree
equivalent age
temperature crack
extended finite elements
