Research On Rapid Assessment Of Seismic Damage For Spatial Latticed Structures

Spatial latticed structures mainly includes the reticulated shells,space grid structure,the spatial truss structure and so on.These structures are widely applied to various large-scale gymnasiums,airport terminal buildings large theater and other public facilities due to the advantages of good structural rigidity,light weight,beautiful appearance and good overall mechanical performance.China a country of frequent earthquakes,and these structures are often used as shelters or disaster relief command post after earthquakes.Therefore,it is especially important to assess the damage status of structures promptly to determine whether the structure can disaster relief to formulate disaster relief plans and deploy relief efforts efficiently.Based on studing on failure mechanism under strong earthquake and the fragility analyses with double-layer reticulated domes,the fragility analyses of single-layer reticulated domes,cylinderial domes,orthogonal pyramid space grid and spatial truss structure are carried out in this dissertation,and then to establish earthquake damage assessment model of five kinds of spatial latticed structures.The main contents are as following:1.The incremental dynamic analyses are performed on long span double-layer reticulated domes.The response characteristics and destruction mode under strong earthquakes are studied.The main failure mechanism of double-layer reticulated domes is obtained.The sensitivity of the four main parameters for earthquake response of double-layer reticulated domes is analyzed.The sensitivity of the parameters is used to determine subsequent sampling as a random factor or a deterministic factor.2.The scalar ground motion intensity measure and structural damage index for double-layer reticulated domes are determined.The performance level of the double-layer reticulated domes is divided and quantified so that the structure damage levels can be rapidly judged according to the size of the structural damage index established.The incremental dynamic analyses are performed on multiple single-layer reticulated domes,single-layer cylinderial domes and double-layer reticulated domes,using 40 ground motion records.Earthquake information and the response to a statistical analysis.The seismic demand models are established based on ground motion intensity measure and structural damage index.The seismic demand models of orthogonal pyramid space grid and spatial truss structure are established.The rapid assessment models of structural damage under earthquake are established based on the statistical analysis of the seismic demand models,and the validity has been verified.3.The incremental dynamic analyses are performed on 4 actual project,using 40 ground motion records.The seismic demand models are established and compared with obtained from the rapid assessment model established earlier.The improved seismic damage assessment model in complex space grids is proposed.The fragility curves and fragility matrix are obtained to evaluate the seismic performance of the structure.The rapid assessment method based on seismic fragility matrix is proposed,which is more suitable for rapid assessment of seismic damage of complex long-span space structures.The rapid assessment model for seismic damage is integrated into the urban engineering earthquake disaster prediction and assessment system,so that lay the foundation for the popularization and application of research results in our country.