混凝土浇筑期是高大模板支架最危险的时期,为了了解这一时期的高大模板支架的工作状态,该文对两个模板支架进行了内力的静态和动态实测。测试结果表明:立杆所受到的最大荷载出现在浇筑过程中,而不是在浇筑结束后;支架整体工作;个别立杆在浇筑过程中退出了工作,使得附近立杆的轴力大幅度提高。该文对这一现象进行了分析,根据试验和分析结果,掌握了高大模板支架的工作状态,提出设计时应将混凝土荷载视为可变荷载,并忽略浇筑和振捣混凝土产生的荷载动力效应。
High falseworks are in the most dangerous state during concrete placement.In order to investigate the working state in that period,in-situ static and dynamic tests of member axial forces were carried out in two construction projects.The test results show that the maximum loads on vertical tubes occur during the pouring process,rather than the end of pouring.The falsework works as a whole structure.In addition,a special phenomenon is found that one of measured vertical tubes stops sustaining load gradually,leading to a significant increase of the axial forces of vertical tubes at juxtaposition;this phenomenon was analyzed in this paper.Based on the results of tests and analyses,the working state of high falseworks was addressed.It is suggested that,during concrete placement,fresh concrete load should be treated as a live load and the dynamic effects caused by placing concrete and vibrating concrete can be neglected.