关键词: 湿度场;干缩应力;衬砌;温湿耦合应力;养护时间;有限元方法;

Abstract: The wet curing for concrete lining is a key factor to determine its structural safety.In this paper, the shortest wet curing time after the completion of large-scale lining structure pouring was studied.Firstly, the finite element method was used to model and solve the large-scale lining structure, and the two main stresses in the lining pouring process were obtained, the position and direction of the extreme value of temperature stress and shrinkage stress.Then, based on the simple temperature-humidity field coupling stress calculation method, combined with the change trend of allowable tensile strength of concrete, the minimum wet curing time of lining structure was clarified.The results showed that the drying shrinkage stress was more harmful to the lining structure than the temperature stress; for thin-walled concrete structures, wet curing can delay the occurrence time of the extreme value of coupling stress in lining pouring and reduce the risk of lining cracking.Under the action of temperature stress, the shortest wet curing time of thin-walled concrete structure was the key to preventing dry shrinkage cracks.

Key words: temperature field; drying shrinkage stress; lining; coupling stress of temperature and humidity field; curing time; finite element method;