Dynamic Evaluation Of Safety Risk In Welding Overhead Mould Frame Construction Based On DBO Model

China's super high-rise building began to develop from 1976,and it entered the stage of ultra-high speed development after 1990.With the rise of super high-rise buildings in China and even in the world,the construction technology of high-rise buildings was also undergoing great changes in terms of their high height,difficulty in construction,difficulty in enclosure,and high safety risks.At present,many super high-rise constructions had adopted the welded overhead formwork system when constructing the core tube.Although the welded overhead formwork system brought great convenience in the construction of super high-rise buildings,it was bulky,heavy,and difficult to control.Once a safety accident occurs,it could be very serious.It was imperative to carry out and strengthen the work on the safety evaluation and research of welded overhead formwork systems,to explore the various causes and related approaches that lead to engineering accidents,and to adopt measures for mining prevention and control that suit local conditions and achieve welding.The damage caused by the failure of the lifter system was prevented or reduced.In this thesis,the DBO model was used to qualitatively analyzed the instability of welded overhead jigs in engineering examples,and the safety barriers were listed to isolate the accidents and events.After that,the dynamic fault tree analysis method and the dynamic event tree were used.The analytical method quantitatively analyzed the failure probability of a welded overhead jig frame failure accident,and concluded that points of non-uniform lifting,excessive local loads,and elevation controlled errors need to be paid attention in the construction process and evaluated.The safety risk level of engineering examples.Finally,combined with the design calculation of the structure and field stress test results,the analysis results of the above DBO model were verified,the persuasiveness of the analysis results was enhanced,and the feasibility of the application of the DBO model in the construction process of the welded lift formwork system was also verified.The DBO model proposed in this thesis integrates the static Bow-tie model and makes up for the lack of quantitative analysis.It is believing that there will be good development and application in the subsequent research process.