钢筋混凝土受弯构件长期变形的通用分析方法

General Analyzing Method on Long-Term Deformation of RC Bending Element

目的针对钢筋混凝土受弯构件的长期变形,提出通用合理的分析方法,研究归纳钢筋混凝土受弯构件的长期变形基本的性质规律.方法考虑混凝土实际的徐变、收缩效应、裂缝影响及应力重分布变化全过程,推导了适用于不同应力分布条件下受弯构件长期变形的通用公式,应用迭代分析计算程序对各种受弯构件的长期徐变收缩效应及挠度变形进行了仿真分析.结果通过与试验对比验证,通用公式计算结果与试验结果间平均误差低于10%.同时研究归纳了各重要因素对受弯构件长期变形的影响规律,并在设计规范建议的基础上提出了简化的多参数修正系数法,合理地预测了受弯构件长期挠度增大的影响系数,最后说明了该多参数修正系数法的可行性.结论采用通用公式分析钢筋混凝土受弯构件的长期变形所得到结果较合理准确,在其基础上简化提出的多参数修正系数法便于工程应用.

A general analyzing method was put forward so as to induce the nature and principle of the longterm deformation of reinforced concrete bending elements. Considering creep, shrinkage effects, crack effect and nonlinear stress distribution, the long-term developing procedure of reinforced concrete bending elements were analyzed. General analyzing method for different stress distribution curves was presented and deduced. Emulational calculation program was compiled to research the time-dependent effects and deflection of different bending elements, and verified by the experiment results. Primary influencing factors and their laws were effectively simulated and concluded. And based on codes＇ requirements, multiple-parameter adjusting method was suggested to calculate the long-term deformation factor of bending element. As a conclusion, the feasibility of simplified method was proved.