Prefabrication Of Middle Beam Of Cable Tower Based On Virtual Construction Assembly Safety Analysis

In the western region of my country,limited by its special geographical conditions,it is necessary to build a large number of large-span bridges that span canyons and rivers.Therefore,large-span cable-supported bridges such as suspension bridges and cable-stayed bridges are often designed on the line.As a cable-supported bridge,the importance of the pylon is self-evident,and the pylon beam is the key component of the cable-supported bridge,which generally adopts cast-in-place construction and prefabricated lifting construction.Due to the particularity of the position of the pylon beam,its support is generally a high-altitude support.The high-altitude installation of the construction support and the construction bracket is risky,and the installation quality control is difficult;the beam is large in shape and requires high precision during prefabrication and lifting.Greatly affected by force.And it is affected by wind,temperature and climatic factors during the construction process.These characteristics determine the complexity and risk of the construction of the pylon beam.During the construction of pylon beams,the analysis and control of safety risk sources have become an important issue in the process of beam construction.However,in engineering practice,there is a lack of comprehensive and systematic risk source management and control for the construction of pylons and beams.Therefore,the analysis and control of the safety risk of beam construction is of great significance for improving the theory of bridge risk management,and for guiding engineering practice and ensuring project construction goals.The realization of it also has important practical significance.Combined with engineering examples,this paper uses building information modeling(BIM)technology,Internet and other technologies combined with traditional risk assessment theory to propose and apply the beam construction risk assessment method based on BIM technology,and finally uses the simulation analysis and calculation of major risk sources to formulate corresponding risk control strategies.This article specifically completed the following work content:(1)Risk management theory identification and analysis:Considering the uniqueness of beam construction,on the basis of summarizing the factors affecting its construction safety,the fault tree of beam construction safety is established,the main accident mode and key influencing factors affecting beam construction safety are analyzed,and the monitoring system is established with the main accident mode and key influencing factors as the main monitoring objects;(2)Safety risk source analysis and control:After determining the risk,the hierarchical analysis structure is established,the theoretical knowledge related to the triangular fuzzy number is introduced,the risk is graded and evaluated by the analytic hierarchy method,and the proportion of various risk weights is determined;finally,the applicability of BIM technology to the risk assessment of beam construction is analyzed,the modeling method of bim model of beam construction is studied,and the beam structure model is established by Revit and Civil3D.The necessity of web display of beam construction BIM model is discussed,and the Web display of beam construction model of Fenglint Bridge is realized based on the BIMFACE platform of Guanglianda.(3)Based on the establishment of bim model and web display,on the basis of establishing the BIM database,a risk assessment program was written and a beam construction risk management evaluation system was independently developed.And the system was applied to the construction of the beam project of the Fenglint Bridge.Through the expression of the BIM model and the collection of information of the project,the risk assessment calculation was carried out,and the construction process was analyzed in real time and systematically.(4)Calculation analysis:In view of the safety risks of the main structure displayed in the virtual construction of the new process,the simulation calculation and analysis of major risk sources such as the prefabricated beams in the construction process to improve the safety and improve the safety of the main body of the Tower during construction were completed,and the effective reduction of the safety risks of the new process construction was promoted through the application of various measures,and the reliability and safety of the new process were further strengthened.