扣件式高大模板支架的概率极限状态设计法研究

近年来高大模板支架坍塌事故频发，尽管此类结构的验收标准低、荷载离散性大，但有关概率极限状态设计法的研究还十分不足。以搭设高度在7.6 m~14.0 m较为常见的扣件式高大模板支架为研究对象，给出了极限承载力的非线性简化计算方法，对比足尺整架试验数据，研究计算模式不确定性的统计特性；通过对现场采样数据、已有试验数据和容许误差等的分析，得出了满足规范要求的随机参数的统计特性；通过1000次Monte Carlo模拟得到了10种常用高大模板支架极限承载力的统计特性；基于枚举优化法，找出了与目标可靠指标一致性最佳的荷载效应分项系数和抗力分项系数，并将采用该文所建议方法得到的设计结果与按英国规范、我国现行规范得到的设计结果进行了比较。研究成果可为制定新规范提供理论依据。

DESIGN METHOD OF LOAD AND RESISTANCE FACTOR FOR HIGH FALSEWORK WITH COUPLERS

Many collapses of high falseworks have occurred in recent years. The research on the design method of load and resistance factor for high falseworks is not efficient in spite of the lower standard of quality acceptance and the larger discreteness of load compared with those of permanent structures. Thusly, high falseworks with couplers (HFC) with height of 7.6m to 14.0m are taken into account. A simplified nonlinear calculating method of ultimate capacity is suggested and the statistic characteristics of model uncertainty are estimated by comparing the full-size test capacities to the predictions. In the range of tolerances given by the code, the statistics of uncertain parameters are obtained based on the samples collected in construction fields, test data and tolerances given in the code. The ultimate capacity statistics of 10 typical HFCs are estimated through 1000 Monte Carlo simulations. The optimal factors of load effect and resistance are found in terms of Enumeration Method. Design results given by the methods, and the British Code as well as the Chinese Code are compared. The results can provide a theoretical foundation for a new code.