Study On Construction Technology And Monitoring Of A New Composite Cable Dome

Cable dome structure is composed of a number of continuous flexible cables and discontinuous compression bars which developed in the 20 th century,80 years.It's a very efficient structure of the tension cable system.Due to the light weight,beautiful shape and cleverly conceived,cable dome structure develop quickly in the next three decades,and has been successfully applied in lots of large span structures abroad.A few projects have adopted a cable dome roof structure,but the structure of the construction technology research is still in its infancy,compared with mature foreign construction technology there is a gap,so it is necessary to continue to carry out in-depth study.With the improvement of China's economic and construction technology,a small number of domestic projects have adopted the cable dome roof structure.But the construction technology research is still in its infancy.Compared with the mature construction technology abroad,there is still a gap.So it is very necessary to continue to carry out in-depth study.The author take the cable dome of Tianjin University of Technology Gymnasium(hereinafter referred to as the project),which is the composite cable dome with the largest span inbroad with the designing he and the task group participated in as the engineering background.This project has saddle-shaped outer ring beam and its roof structure is complex.First of all,we reviewed the engineering application of the cable dome and the problems encountered in the construction process.Combined with the shortcomings we found during construction at high altitude,we proposed a tower lift construction method to reduce the internal force of cables during construction.According to the installation and tension programs of this project,this article adopts the method of inverse simulation,using the large scale general finite element software ANSYS and its element birth and death technology to simulate the whole process of this cable dome.The internal force of cables and coordinates of each node are obtained at each construction control step so as to provide data for the construction site.Aiming at the forming method of outer slope cables,three different regular successions are compared,we found that the most reasonable way is tensioning oblique cable alternately.The author makes a detailed analysis on the dimensional error of ring beam and cables which are the most difficult errors to control during the construction of cable dome.It is found that both the external oblique cables and the external ridge cables need adjustable ends to offset the construction error of the ring beam and the cable feeding error should not be larger than 1/1000 of the cable length.During the construction period of this project,the authors used the total station and the vibrating rails arranged on the struts to collect and analyze the change of the coordinates of nodes and the change of stress during the construction.And we compared them with the finite element results to verify the reliability and accuracy of the construction program.In order to verify the correctness of the tower lift construction method proposed above,based on the background of this project,a 1:15 test model was made.The design of the test piece is described in detail,and the comparison of the two construction methods is carried out to verify the feasibility of the tower lift construction method.Through the above analysis of the construction technology and construction monitoring of the project,it can provide certain reference for the construction plan and construction monitoring of composite cable dome projects.