考虑收缩徐变混凝土水化放热仿真分析在跳仓法施工中的应用

Application of hydration heat release simulation analysis of concrete considering shrinkage and creep in construction of alternative bay method

从混凝土强度、弹性模量时变模型及收缩徐变模型入手,对比分析了《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG 3362—2018)模型、《大体积混凝土施工标准》(GB 50496—2018)模型、CEB-FIP(1990)模型、ACI模型,对某在建项目大体积混凝土进行了温度应力监测,并基于Midas软件进行了仿真分析。结果表明,《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG 3362—2018)模型及CEB-FIP(1990)模型的温度及应力结果与实测结果吻合最好,验证了本文计算方法的可行性。最终,将考虑收缩徐变的水化放热计算模型应用于某174.9 m×214.6 m超长筏板结构的施工过程分析中,结果表明,所采用的跳仓方式及施工措施能够保证温度及应力水平满足要求。

Starting with the time-varying model of concrete strength,elastic modulus and shrinkage and creep model,Specifications for design of highway reinforced concrete and prestressed concrete bridges and culverts(JTG 3362—2018)model,Standard for construction of mass concrete(GB 50496—2018)model,CEB-FIP(1990)model,ACI model were compared and analyzed.Through temperature stress monitoring of a large volume concrete under construction project,simulation analysis was carried out based on Midas software.The result shows that the temperature and stress results of Specifications for design of highway reinforced concrete and prestressed concrete bridges and culverts(JTG 3362—2018)model and CEB-FIP(1990)model are in good agreement with the measured results,which verifies the accuracy of the calculation method in this paper.Finally,the calculation model of hydration heat release considering shrinkage and creep was applied to a 174.9 m×214.6 m super-long raft structure.It can be concluded that the jump mode and construction measures adopted can ensure that the temperature and stress level meet the requirements well.