Construction Scheme Comparison And Simulation Calculation Of Super Large Span Dry Coal Shed String Structure

With the deepening of environmental protection consciousness,large coal yard has changed from open stacking to closed storage.With the progress of construction engineering technology and the improvement of the use function of closed coal yard,the span of closed coal yard structure is required to become larger and larger,which puts forward higher requirements for the design and construction of closed coal yard structure.Beam string structure is an efficient long-span spatial steel structure based on the concept of tensegrity.It is composed of continuous tension members and compression members to support the upper compression structure.In the working process of beam string,the prestress makes the cable structure produce a certain reverse deflection,so the actual deflection of the whole superstructure under the load is reduced;the elastic support provided by the brace to the bending members of the superstructure makes the whole structure stress reasonable.As one of the large-span prestressed structures,beam string structure can meet the needs of dry coal shed,but the construction technology of dry coal shed with beam string structure is more complex because of its super large span and the existence of prestressed cable tension.This paper compares and determines the construction scheme of the project,and carries out the whole process simulation calculation and Analysis on the determination of cumulative sliding construction method.Finally,the paper briefly introduces the synchronous control measures and facilities in the process of sliding,calculates the non synchronous deviation of sliding,and analyzes the size rule of deviation.(1)This paper introduces the common construction methods of beam string dry coal shed structure.According to the characteristics of the project,the jig support method,cumulative sliding method and lifting method are selected,and three construction schemes are drawn up according to three construction methods.Through the finite element analysis software MIDAS / Gen to divide the construction section and analyze the cumulative model,the change trend of cable force,support reaction force and mid span displacement in the construction process of three construction schemes are obtained.Combined with the actual situation of power plant coal shed,the cumulative sliding method is finally selected for construction.(2)According to the design and construction data,the whole structure model is created by using the finite element software MIDAS / Gen.The key points of model establishment,load addition and construction section division in the process of policy calculation are briefly discussed.According to the determined cumulative slip construction scheme,the construction section is divided by the activation and passivation of the structure group for calculation.The change process and the most unfavorable state of cable force,displacement,support reaction force and steel structure stress in the construction process are obtained,which can provide reference for the actual construction.(3)For the analysis of slip deviation in the construction process,this paper briefly describes how to control the synchronous slip in the project,and calculates and analyzes the possible deviation in the slip,respectively calculates the internal force generated under different slip asynchrony,so as to find out the limit value of the asynchrony,and finds that the limit value of each slip is different,so as to calculate the maximum slip allowable value of each slip The allowable limit value and the rule are analyzed.