Seismic Response Analysis Of Large-span Spatial Truss Structure Under Multi-support Excitations

Because of reasonable force,graceful shape and high degree of factory,Large-span spat ial truss struct ure has been widely used in large public buildings such as stadiums,theaters and exhibition centers.Because natura l frequencies of the structure concentrate in a small range and its span is large,the influences of space effects of seismic ground mot ion cannot be ignored.Therefore,study on the influence of multi-support excitation effect on large-span spatialtruss structure has a great significance for the structure safety during the earthquake.This article has taken the steel roof struct ure of Linxia Olympic center stadium as the research object,and mainly has analyzed the seismic response of this structure under multi-support excitat ions and under single-support excitat ions by using time history analys is method.The effects of multi-support excitations on seismic response of the large-span spatial truss structure have been obtained.The main research work is as follows :(1)Seismic responses of the structure for horizontal and vertical earthquakes under multi-support excitat ions and single-support excitations have been analyzed and compared.The change of bar internal force under horizontal and vertical earthquake multi-point input has been studied.The main factors affecting the change have been analyzed.The rule of seismic response of the structure under one-dimensional and multi-support excitations has been summarized.(2)Seismic responses of the structure under two-dimensional and three-dimensional earthquakes under multi-support excitations and single-support excitations have been analyzed and compared.The change of bar internal force under multi-support excitations has been studied.The main factors affecting the change have been analyzed.The rule of seismic response of the structure under multi-dimensional and multi-support excitations has been summarized.Studies have shown that considering traveling wave effect,multi-support excitations have an effect on member internal force of large-span spatial truss structures and the impact is connected with the species of seismic wave,the value of wave velocity,spread directions of seismic wave,the constraint of components and the number and action direction of seismic wave component.Besides,multi-support excitations have different impact on internal force of structure bars in different positions.When analys is seismic response of grid structures,When seismic response of large-span spatial truss structures is analyzed,three-dimensional and multi-support earthquake excitations should be considered.