| The vertical seismic response of non-isolated structure and horizontal isolated structure is relatively large,and it is easy to have adverse effects on the non-structural components such as indoor equipment and suspended ceiling.In recent years,the postearthquake functional research of structures has been paid more and more attention.The emergence of three-dimensional isolation technology has effectively reduced the vertical response of the structure.At present,non-structural components are seldom considered in the study of seismic performance of 3D isolated structures,and the deterministic research method in time domain is generally adopted,which ignores the impact of seismic performance evaluation caused by the uncertainty of ground motion.In this paper,through numerical simulation,the non-isolated,horizontal isolated and three-dimensional isolated steel frame structure analysis models including equipment are established.Based on the incremental dynamic analysis method,the seismic fragility research of typical non-structural components such as structure,equipment and suspended ceiling is carried out.The main contents and conclusions are as follows:(1)The seismic fragility of three-dimensional isolated structure is studied.Considering only the interstory displacement angle of the superstructure,the threedimensional isolated structure can achieve the same shock absorption efficiency as the horizontal isolated structure,and the fragility is much lower than that of the non-isolated structure.The rocking characteristics of the three-dimensional isolated structure make its fragility slightly higher than that of the horizontal isolated structure,and restricting the rocking of the structure can effectively improve this problem.When considering the displacement of the isolation layer,the fragility of the two isolated structures is improved and they are relatively close.The fragility of the structure is higher in the near field than in the far field.(2)The seismic fragility of slip-type equipment is studied.The shock absorption efficiency of horizontal isolation and three-dimensional isolation to the horizontal acceleration of the structure can reach more than 50%,which makes the fragility of slip-type equipment lower than that of non-isolated structures.The rocking of the threedimensional isolated structure causes the equipment fragility to be slightly higher than that of the horizontal isolation structure.Under the action of near-field earthquakes,the fragility of equipment is higher than that in the far-field.(3)The seismic fragility of overturned equipment is studied.The horizontal isolated and three-dimensional isolated structure can effectively reduce the overturning probability of the equipment.The overturning probability is only 7% under the action of a strong earthquake with a PGA of 0.8g,while the non-isolated structure is as high as 80% or more.In the horizontal isolated structure,the rocking angle of the equipment is larger,up to 0.18 rad,while in the three-dimensional isolated structure,the rocking angle of the equipment is generally kept within 0.025 rad,which can be kept in a relatively static state approximately with the floor,which can maintain the postearthquake functionality of the equipment.(4)Seismic fragility of suspended ceiling is studied by vertical acceleration of floor.Compared with the non-isolated structure,the vertical acceleration of the floor slab in the horizontal isolated structure has a magnifying effect,which is easy to have an adverse effect on the suspended ceiling.The three-dimensional isolation can effectively reduce the vertical acceleration.Under the action of a strong earthquake with a PGA of 0.8g,the probability of the ceiling being in a basically intact state can reach more than 60%.Under the action of near-field earthquakes,the fragility of suspended ceilings in non-isolated structures and horizontal isolated structures is higher than that in the far-field,while the three-dimensional isolated structures show the opposite law. |
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