Field Welding Splice Joint Reinforcement Design And Monitoring Analysis Of The Long-span Steel Truss Roof

Large-span steel truss is often produced in section in the factory and is installed by weld splice in site.steel truss component which splicing weld quality is not guaranteed often become a weak link,and can't guarantee security,applicability and durability of the structure.Large-span steel structure roof system is used in the roof of a project which is composed of five common of main truss and truss 11 common truss.Construction quality of weld splice directly affect the bearing capacity and the security of structure and force structure to enter the shutdown on the way.Steel structure needs to be reinforced and eliminate hidden dangers before the extension.In this paper,key technique of strengthening to steel truss is studied in background of strengthening and monitoring project during construction on large-span steel structure roof system of a project.Based on the serious quality problems of web welding found by project detection,considering the component mechanical characteristics,Combining with the construction environment,the method of welding symmetrically steel plate in outer edge of H shape steel to increase the weld,change welding section form was adopted to reinforce the weld splice joints.In order to verify the validity of the reinforcement design,the numerical simulation was used to analyse mechanics performance.The mechanical characteristics of defective components before and after reinforcement under the general states are further studied.The effect and regularity about splice plate' Strengthening to the on-site welding stitching node is analysed base on these parameters such as the length of the weld defect,the size of the reinforcement splice plates,component loading form and so on.The construction control was adopted to guarantee the safety of the structure and improve the quality of reinforcement,and the monitoring was adopted to determine the stress and displacement state of weld splice joints in the process of construction.Based on the comparison and analysis on the results of numerical simulation and strain test,it was proved that web reinforcement enlarged cross section method became effective on the transfer of force.Thesis analysis results could provide important reference for the reinforcement design of other similar steel structure project.