Three-dimensional Isolation Analysis Of Long-span Spatial Reticulated Shell Structure

The space reticulated shell has beautiful structure,good force transfer performance and wide application.However,its structural system is complex,and its dynamic characteristics are affected by span,structure form and other factors.The natural frequencies are densely distributed and some high order modes contribute greatly to the dynamic response of the structure.Structural vibration has multi-dimensional characteristics and is significantly affected by vertical seismic forces.However,the contradiction between vertical isolation and load bearing of supports should be solved urgently.Therefore,this paper explores the rule of three-dimensional seismic isolation of long-span spatial reticulated shell structures,and focuses on solving the contradiction between vertical seismic isolation bearing and seismic isolation.Firstly,the dynamic characteristics of reticulated shell structure are analyzed by modeling software such as MST and ANSYS,and the feasibility of three-dimensional isolation support is verified.It is proved that the low order horizontal and vertical natural vibration periods can be effectively prolonged and the excellent period of ground motion can be avoided.The vertical and horizontal stiffness of reticulated shell structures with spans from 40 m to 150 m are calculated and analyzed.Furthermore,the advantages and disadvantages of the existing three-dimensional isolation bearing are analyzed and summarized,and a scheme of considering the contradiction between bearing bearing and vertical isolation is put forward.The device is to connect the disc spring with the helical spring in parallel and use the lever to improve the bearing capacity.By using the output formula of the vertical isolation device,the stiffness curves close to the isolation and load-bearing requirements of the reticulated shell structure are obtained by adjusting the key component parameters of the device.Finally,the isolation effect of the new three-dimensional isolation device in the reticulated shell structure is given by time-history analysis and response spectrum analysis under ground motion loading.The isolation effect of reticulated shell structure is analyzed.On this basis,the influencing factors of isolation effect and isolation mechanism are further explored.