Construction Process Simulation And Seismic Performance Analysis Of Spoke-type Beam String Structure

As a new type of space structure system,the beam string structure has the characteristics of long span,high height and flexibility.Its stress distribution is reasonable and its shape is beautiful.It has been widely used in many kinds of long-span structures.As a new type of structure,spoke beam string is different from ordinary one-way and two-way beam string.At present,the research results on unidirectional and bidirectional beams can not be fully applied to spoke beams.Based on the spoke beam string structure of a central plaza in Nanjing,Jiangsu Province,this paper studies its construction process,natural vibration characteristics and seismic response through numerical modeling.The contents and conclusions are as follows:1.The finite element software Midas Gen is used to establish the analysis model of the whole structure,and the model is validated by comparing the field measured data.On this basis,the key construction process of the spoke beam string structure is simulated,and the internal force and deformation of each member in different construction stages are analyzed.The results show that the internal force of the bottom column and the bifurcated column varies greatly during the construction process.The internal force redistribution occurs when the temporary support is removed to complete the structural system transformation,the internal force of the bottom column increases sharply,and the deformation of the ring truss is larger.2.The natural frequencies and main influencing factors of the spoke beam-string structure are analyzed.The calculation shows that the horizontal stiffness of the structure is small,the influence of increasing the prestress value and the size of the upper chord section on the overall stiffness of the structure is limited,and the reasonable selection of the brace position is conducive to improving the overall stiffness of the structure.3.The dynamic time history analysis of the spoke beam string structure is carried out.Considering the influence of earthquake input direction and intensity,the bottom column bears the vertical load caused by dead weight and the bending moment caused by earthquake;the distribution of internal force of the beam string increases from inside to outside;the calculation results show that the deformation of the key components of the structure meets the requirements of the code,the stress level is within the safe range,and the seismic performance of the structure is better than that of the structure.Structures are more sensitive to earthquake intensity by changing the direction of earthquake input.