Force Analysis And Optimization On The Construction Procedure Of The Tower Of The Single Arch-type Tower Cable-stayed Bridge

With the rise of aesthetics in the whole society,the large cable-stayed bridge itself not only has the traffic function but also has become the iconic landscape of the city.In this form,the beautiful shape of the main tower arch Cable-Stayed Bridge became a business card to promote the image of the city.Arch-type main tower is a kind of novel,Beautiful Cable-Stayed Bridge main tower.This main tower structure due to the characteristics of the arch,the space effect is obvious,the construction is more difficult,the construction process requires more heavy machinery,to install multiple rows of crossbars,vertical support to support the arch of the main tower,the construction phase stress changes generated more intense.Before the construction of the Arch-type main tower,it is necessary to study the force generated by the construction process in advance to ensure the safety of the structure.In this paper,based on the main bridge of Jiangwan bridge,Qujiang Avenue,Shaoguan city,the maximum stress during the construction of the Arch-type main tower is studied,and the relevant parameters are analyzed and the process is optimized.:(1)The construction process of the main tower of the Jiangwan bridge was introduced,based on the Arch-type main tower of the Jiangwan bridge,according to the actual construction conditions,the whole construction process of the Arch-type main tower was divided into 44 working conditions,using ANSYS 18.2 and Midas/civi18.65 two kinds of software to establish the main tower simulation calculation model of the whole process of the construction.(2)The stress analysis of the whole process of Arch-type main tower construction was carried out.The results show that the internal forces and stress results obtained by the two software are basically the same.In the tensioned Tower column between 60.274-69.274 m prestressing steel stage,the tower appeared under the greater tensile stress(ANSYS results 2.28MPa;Midas/civil results 2.76 MPa),close to the C50 steel fiber reinforced concrete tensile stress design strength 2.85 MPA(3.3.2 Section results).After tensioning down the tower 60.274～69.274 m between prestressing steel,tower tensile stress decreased until the tensioned beam construction stage of the second batch of prestressed steel,the outer root of the tower appeared under the maximum tensile stress(ANSYS results 2.66 MPa;Midas/civil results 2.47 MPa),close to C50 steel fiber concrete tensile stress design strength(2.85 MPa).(3)The optimization analysis of the construction process.The second batch of prestressed steel bars of the lower tower are divided into three batches of tensioning to optimize the tensioning sequence of the three batches of prestressed steel bars in three batches,and construction conditions are calculated by Midas/civil.The results show that the maximum tensile stress can be effectively reduced by batch tensioning prestressing tendons.(4)The parameter analysis of the temporary crossbars and the pre-top force is carried out.Change the cross-brace position,before installing the cross-brace Tower were applied 10kN,20kn,30kN by the tower center point to the outside of a pair of pre-top Force,different construction conditions Midas/civil calculations show that these two factors no effect on the cross-section stress.