| In recent years,with the development of construction in new socialist countryside and increasing transportation infrastructure,the transportation construction in mountainous areas and scenic spots has faced the new developments.Flexible suspension bridges have the advantages of spanning ability,reasonable forcing,low cost and beautiful shape,and have gradually became a hot spot for bridge selection in mountainous areas and scenic spots.Cable hoisting construction has always been the primary choice for flexible suspension bridge construction in mountainous areas,which is an economical,efficient and safe construction method.For a long time,the safety factor of the cable system and the weight of the hoisting equipment in the cable hoisting construction process are generally too large.Meanwhile,it is not easy for large equipment to enter the site,and that would cause damage to the ecological environment.Therefore,lightweight cable hoisting construction plan is an inevitable development direction.However,the lack of national,local standards and effective construction monitoring in the stage of flexible suspension bridges constructions would cause many problems,which should be paid enough attention and studied in depth.Based on the engineering background of the Zhangzhou Zhongchi Villa Flexible Suspension Bridge,this thesis studies the optimization of the cable hoisting construction plan and force analysis of main components in flexible suspension bridge construction stage.According to the conditions of construction,two cable hoisting construction plan were proposed for the designing of flexible suspension bridge construction.The construction process of equipment layout,cable clamp and hanger rod hoisting,main girder hoisting,bridge floor system and subsidiary facilities hoisting was described in detail,which provides references for similar engineering construction.The parabolic theory is used to check the cable system of the cable hoisting plan 1,the results shows that the safety factor is high and the cable system design is not economical.According to the parameters of the cable hoisting system,the relationship between the horizontal tension of skyline,haul line and the sag of skyline is analyzed through Matlab software,which verifies the conclusion of the scholars on the value of the sag of the skyline in the cable hoisting.Through the study of cable hoisting plan 1,it is suggested that forest cableway specifications should be used in the lightweight design of cable system,and the center deflection coefficient should be in the range of 0.04～0.06,which is more reasonable.Solid three-dimensional modeling of the carriage was built in the cable hoisting plan 1 by Solidworks software,as for the part of structure of the carriage and the arrangement of the haul line,the functional optimization of the carriage is carried out to improve the lifting efficiency.The finite element analysis and size optimization of the frame of the carriage were carried out through the Stimulation module in the Solidworks software,which reduces the weight of the carriage and achieves the purpose of lightweight hoisting.Cable hoisting plan 2 realizes lightweight hoisting by changing the hoisting weight,re-selecting the cable system and replacing the carriage,which reduces the cable diameter and the carriage weight while ensuring safety,obtaining a more economical and reasonable cable system plan.Midas finite element software was used to model and analyze the flexible suspension bridge,and then dismantle resulting bridge model to obtain the shape and internal force of the main cable in the empty cable state,which provides the basis for the main cable setting and construction monitoring during the construction process.On the basis of the empty cable status,the construction phases were divided based on the cable hoisting plan,and each construction phase was simulated to solve the force and deformation of each component in each construction phase.Through analysis,the internal forces and displacements of the main components of the flexible suspension bridge undergo the maximum changes in second pavement,and timely monitoring must be carried out to ensure the safety of the construction process. |
