（上海长福工程结构设计事务所， 上海 200011）

［摘要］简述了受压混凝土的徐变基本理论和裂缝间受拉混凝土对开裂构件刚度硬化的分析模型，并解读了GB 50010—2010，ACI 318-08的EC 2∶2004有关裂缝和挠度计算条文的理论背景。其中，EC 2∶2004使用徐变系数φ(t,t0)、混凝土龄期调整弹性模量E—c(t,t0)和刚度插入系数ζ，三个反映徐变和开裂刚度的设计参数来计算裂缝宽度和长期挠度的半经验公式，既适用于梁，也适用于双向板。另外一个方面，由于双向板主应力方向随平面位置变化，使用植入φ(t,t0)，E—c(t,t0)和ζ的板单元进行有限元非线性分析，是计算双向板裂缝和长期开裂挠度的通用方法。在列出了有限元非线性分析的基本流程后，作为一个算例，使用CSI. SAFE完成了地下室柱支撑双向顶板的截面设计及使用极限状态的裂缝和长期挠度的验算，并与板带分析法进行了对比。验证了GB 50010—2010与EC 2∶2004对于裂缝与挠度计算条文的适用性与局限性，并对双向板裂缝和长期挠度的计算方法给出了意见。

［关键词］双向板； 徐变； 裂缝； 长期挠度； 非线性； 开裂刚度

中图分类号：TU375-2文献标识码：A文章编号：1002-848X(2021)02-0015-08

FEM non-linear analysis of cracks and long-term crack deflection of two-way slab

ZHOU Lilang, CHEN Menglong, FU Changsheng

(Shanghai Chinafu Structural Design Inc., Shanghai 200011, China）

Abstract:The basic theory of compressive concrete creep and the analysis model of the stiffness and hardening of cracked components caused by the tension between cracks were briefly described, and the theoretical backgrounds of the crack and deflection calculation provisions of GB 50010—2010, ACI 318-08 and EC 2∶2004 were interpreted. Among them, the EC 2∶2004 provides three design parameters reflecting creep and cracking stiffness to calculate the semi-empirical formula of crack width and long-term deflection, including creep coefficient   φ(t,t0)， age-adjusted elasticity modulus E—c(t,t0) and stiffness interpolation coefficient ζ, and they are generally suitable to both beam and two-way slab. On the other hand, the direction of principal stresses changes in the two-way slab. With the plate-bending elements embedded  φ(t,t0),E—c(t,t0) and ζ, FEM  non-linear analysis is a general method of crack  and long-term crack deflection of  two-way slab. After listing the basic process of finite element non-linear analysis, as a calculation example, CSI.SAFE was used to complete the cross-section design of the basement column-supported bidirectional top slab and the calculation of the cracks in the service limit state and the long-term deflection, also the calculation method was compared with the slab-strip method. The method was compared. The applicability and limitations of the GB 50010—2010 and EC 2∶2004 for the calculation of cracks and deflection were verified, and opinions on the calculation methods of cracks and long-term deflection of two-way slabs were given.

Keywords:two-way slab; creep; crack; long-term deflection; non-linear; cracking stiffness

作者简介：周立浪，硕士，高级工程师，一级注册结构工程师，Email:86381481@qq.com； 通信作者：扶长生，硕士，教授级高级工程师，一级注册结构工程师,Email: cfstruct2016@vip.sina.com。