Mechanical Properties And Construction Sequence Analysis Of MFCBS

The new type vertical prestressed steel structure has applied prestressing force to thevertical building structure with prestressed cable being involved in lateral resistance system.The paper focuses on the study of static analysis and construction analysis of a new typevertical prestressed steel structure---prestressed cable bracing structure. Static analysisincludes structure deformation, internal force of beam and column and the remainingpretension of cable under pretension, vertical load and horizontal load alone as well aspretension with vertical load, wind load combination condition, and making horizontalcomparison with pure frame structure and∧type bracing structure. Construction analysismainly includes structure deformation and internal force variation under the constructionscheme A, making comparison among the final structural deformation and inner forcesobtained by different construction schemes and that obtained by disposable loading,comparing the characteristics of different construction schemes and putting forwardproposals.Through the static analysis of prestressed cable bracing structure, it can be concludedthat the prestressed cable can improve the deformation performance of the mega beam verywell under vertical load. However, the internal force of prestressed cable itself will greatlychange with the structural adjustment. Floating up and down of vertical load has a greatinfluence on internal force and deformation of mega beam and mega column axial force, hasa small influence on horizontal displacement of structural vertex and mega column shear,and the influence degree of mega column moment and cable’s internal force is related tohorizontal load. Floating up and down of horizontal load has a great influence on horizontaldisplacement of structural vertex and mega column shear and moment, but has a smallinfluence on deformation and internal force of the mega beam and mega column axial force.Comparing with other structures, it can be concluded that prestressed cable effectivelyincreases the stiffness of the MFCBS system and makes overall stiffness more uniform.By construction analysis of the prestressed mega bracing steel frame structure, it can bedrawn that structural deformation, especially for mega beam span deflection, has mutationwhen prestressed cables are being stretched and substructures are being lifted during theconstruction process. Mega column axial force gradually increases and moment as well asshear force is greatly influenced by the process of stretching prestressed cable. Internal force of mega beam is largely influenced by stretching pre-stressed cable of the upper large layerand lifting the substructure of the current large layer.After making comparison among the final structural deformation and internal forceobtained by8construction schemes and that obtained by disposable loading, it can be foundthat the final structural deformation and internal force obtained by8different constructionschemes have much difference mutually. Structural deformation value and internal force ofbeams and columns tend to be larger when construction scheme C and D are taken, butconstruction scheme E and F tend to cause smaller Z-directional structural deformationvalue and internal force of beams and columns.