Analysis Of Force Mechanism And Safety Of I-steel Cantilever External Scaffold

I-steel cantilever external scaffold is a common external scaffold in high rise building construction. Compared with traditional ground- mounted scaffold, it possesses some advantages, such as good safety, easy to install, convenient to the construction of the bottom back-filing and so on. To research the force mechanism of I-steel cantilever external scaffold is an important project in relation to safety of scaffold and construction personnel. The design of the external scaffold in current national code, which based on the force mechanism of the plane truss rather than a space steel frame, is a bit different than real force mechanism. Moreover, the deformation influence of the I-steel cantilever external scaffold, when bearing different tightening torques of right angle coupler and unloading of wire rope, is also a project concerned safety. In this paper, force mechanism and deflection are studied, and its primary research and results are as follow:1. Based on the anti-torsion experiment of right angle coupler, this paper ascertains the moment rotation curve of right angle coupler and the tri- linear model of the moment rotation curve. By considered and discarded the unloading of wire rope in an I-steel cantilever external scaffold, basic assumption, calculating diagram and force calculation method are introduced.2. According to current national code, selecting materials, installing parameters, global stability, and strength of components, anti-sliding bearing capacity and deflection are checked. Finally, a scheme of an I-steel cantilever external scaffold is proved to meet the safety requirements of current national code.3. Using SAP2000 finite element software, 3-D models, which discarded the unloading of wire rope in an I-steel cantilever external scaffold, are established to analyze deformation influence of I-steel cantilever external scaffold bearing different tightening torques of right angle coupler. Then, the most reasonable tightening torques of right angle coupler is gained by conclusions when the plan is applied.4. Using SAP2000 finite element software, 3-D models, which considered the unloading of wire rope in an I-steel cantilever external scaffold, are established to analyze deformation of I-steel cantilever external scaffold. Considered the unloading of wire rope, the decreased deflection and increased safety of the I-steel cantilever beam are gained by conclusion.The research results can be as the theoretical evidence to installation, decrease the deflection of the I-steel cantilever external scaffold and increase the safety design of I-steel cantilever external scaffold.