超高模板支架的极限承载能力研究

近年来超高模板支架坍塌事故经常发生,承载力不足是主要原因,该文对模板支架的初始缺陷进行实测,统计分析测量数据,考虑较大的初始弯曲率和不足的钢管壁厚,提出一个新的极限承载力公式;通过非线性有限元理论计算,给出了初始弯曲率和钢管壁厚对极限承载力的影响系数;通过弹性稳定性分析,找出了不同立杆超出顶层水平杆长度下超高模板支架的临界荷载及失稳模态的变化规律,为今后的深入研究打下基础。

STUDY ON LOAD-CARRYING CAPACITY OF SUPER HIGH SUPPORTS FOR FORMWORK

Collapse accidents of super high formwork supports often happened in recent years. The main reason is the insufficient load-carrying capacity of the support. In this study, the initial imperfections for steel tubes are measured in some building sites and the statistical analysis of measured data is presented. Larger Initial curvature and insufficient thickness of tubers are taken into account and a new formula for ultimate capacity is proposed. In terms of Finite Element Method considering material nonlinearity and large deflections, the influence coefficients of initial curvature and thickness of tubes on ultimate capacity are given. Finally the influence of extension length of vertical tube over horizontal tubes on the critical load and the buckling mode are given, which can be the foundation of future research.