| In recent years,with the rapid development of the building materials industry,there has been an increasing demand for large-span space steel grids in the cement industry.However,along with the increase in complexity of large-span space steel grids,collapse accidents of space steel grids have occurred from time to time.In order to ensure the safety of steel mesh frame structure in the construction and use stages,it is of great theoretical significance and practical value to explore the measures to reduce the influence of temperature action on the structure,simulate the construction process,guarantee the stress,deformation and stability of the structure during construction within the allowable range of the code,and optimize the traditional construction sequence of steel mesh frame.This paper takes the steel mesh frame project of Hefei Southern Cement Clinker Depot as the background,and the main research work and related conclusions are as follows.(1)The axial forces,stresses and displacements of the overall structure of the clinker store steel mesh frame under static loads were analyzed,and the results showed that the maximum stress ratio was less than 0.37 and the maximum displacement was less than the L/400 required by the code,which verified the reasonableness of the mesh frame model design.(2)The temperature magnitude and the elastic stiffness of the bearing will affect the internal force and displacement of the structure.The use of elastic bearing can reduce the temperature stress of the rod,which verifies the reasonableness of using elastic bearing with stiffness of 6k N/mm in this project.(3)The construction process of the steel grid structure of the clinker store was simulated and compared with the primary forming structure by using the local bit-type restrained raw and dead unit method,and the results showed that the maximum displacement in the final construction stage was less than the L/400 required by the code,and the maximum stress ratio of the bars was less than 0.5,which verified the feasibility of the selected construction scheme.The maximum displacement in the construction stage is slightly less than that of primary forming,and the maximum stress is 22.5%higher than that of primary forming,which indicates the necessity of construction process simulation analysis.The displacement and stress changes of the grid frame are larger in the stage of removing the third ring bearing fixings and adding equipment in the warehouse roof room,which need to be focused on during the construction.(4)By adjusting the construction sequence,the maximum stress at completion was reduced by 5.36% when the support fixings were removed after the eighth ring of the grid was closed compared to the third ring,and the maximum displacement was reduced by 12.77% compared to the removal after the grid was completed,which provided a reference for the optimization of the construction plan.(5)Linear and nonlinear buckling analysis was performed for key construction stages,and the results showed that the addition of temporary diagonal ropes could significantly improve the stability of the structure,and the mesh was insensitive to initial defects during construction after the addition of diagonal ropes,and the stability coefficient decreased insignificantly after the removal of the bearing fixings,indicating that the construction accuracy should be controlled as much as possible during construction,but the structure was also allowed to have smaller initial defects.The research results of this paper can provide a reference for the optimization of the construction scheme and engineering application of steel mesh frame for cement clinker storage.Figure [103] table [16] reference [69]... |
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