Research On Safety Analysis Of Temporary Structure Of Continuous Beam Bridge In Cantilever Construction

The development of the bridge project is a microcosm of the progress of the transportation industry and the entire society.Because of its own structural advantages,the prestressed concrete continuous beam bridge always occupies a dominant position in the bridge span range of the 40 to 150 meters,and the cantilever method is used as a continuous beam.The most widely used one of the many construction methods of the bridge has always been highly concerned.At the same time,frequent accidents during construction of cantilever beams in continuous beams have led to more and more people thinking about the safety of bridge construction.However,temporary structures,as a key influencing factor,require more safety analysis and research.In this paper,the simulation and safety analysis of the support structure,the hanging basket structure,the rigid section skeleton structure and the temporary anchorage structure of the Chaobaihe Bridge during the cantilever construction are carried out.The results of the analysis show that the Chaobaihe Bridge adopts the temporary anchoring form of commonly used or even mainstream temporary supports.Under certain operating conditions or extreme conditions,there are certain potential safety hazards.Therefore,the structural form of the concrete-filled steel tubular columns was changed in the actual project.Taking the temporary anchorage structure as the research object,a deeper level of safety evaluation and analysis was conducted.The safety evaluation system for bridge construction includes risk identification,risk assessment and safety decision.According to the characteristics of bridge construction safety,the fuzzy analytic hierarchy process combined with AHP and fuzzy comprehensive evaluation method was used to evaluate the safety of temporary structures.On the basis of fully collecting engineering safety data,a special risk identification is performed on the temporary anchorage structure of continuous beams.The risk factors are determined based on the risk factors by determining the risk factors according to the degree of importance of the system and using a pairwise comparison method to build a judgment matrix.Each risk factor is evaluated with the resulting consequences,and combined with its weights to perform comprehensive safety assessment in two levels.The safety factor of the temporary anchoring structure is extracted from the final evaluation results,and special safety measures are formulated according to the safety evaluation grade to ensure the safety of the structure and the smooth progress of the project.After the safety factor is applied to the actual project,safety evaluation is performed on the temporary anchorage structure of the continuous beam using different temporary anchoring methods and spans,and the safety factor is extracted and compared to obtain the safety factor corresponding to the more appropriate safety assessment level.