Study On Seismic Performance And Seismic Control Of Shell Wall Structures With Weak Linking-Slabs Under The Action Of Rare Earthquakes

With the development of social economy in our country,more and more high-rise buildings with complex shapes have emerged in our country.The multi-tower connected structure is one of the representatives of these high-rise buildings with complex shapes.The multi-tower connecting structure is very popular among designers because of its unique shape and novel style.However,the multi-tower connected structure under earthquake is complicated,especially the internal force of the intermediate connection structure is affected by many factors,which is prone to damage and lead to the sudden reduction of the seismic performance of the whole structure.In order to fully study the factors affecting the performance of weak connections and the seismic performance of the whole structure,this paper takes the shear wall structure with weak connections as the model.Firstly,the elastic-plastic time history analysis of the shear wall structures with weak connections under large earthquakes is carried out by using professional non-linear analysis software,which changes the design parameters.From the stress state of the connection plate and the damage state of the shear wall,the component levels are indicated.In order to evaluate the effect of design parameters on the seismic performance of weakly connected floor slabs and the overall seismic performance of the slabs,the overall structural indicators such as inter-story displacement angle and base shear force are used.Then,the seismic vulnerability analysis method is used to analyze and evaluate the influence of the symmetry of the lateral stiffnessof the two towers on the seismic performance of the structure.Finally,lead rubber bearings with different horizontal stiffness are added to the connecting floor to study the effect of different horizontal stiffness of the bearings on the seismic performance of the structure under large earthquakes.This paper mainly carries out the following aspects of research work:(1)Elasto-plastic time history analysis of shear wall structures with weakly connected slabs under large earthquakes is carried out through ten design parameters,and the effects of different design parameters on the seismic performance of shear wall structures with weakly connected slabs under large earthquakes are compared.The following conclusions are drawn:1.When the ratio of effective width of connecting slabs to the width of typical slabs B b/B1 increases from 0.11 to 0.56,the two-way base shear increases by 9.45% and 10.85%.The maximum interlayer displacement angle increases by 7.06% and decreases by 5.81%respectively.At the same time,with the increase of connection stiffness,the damage of connecting beam and shear wall components increases,and the stress of connecting plate increases by 80.07%.2.The ratio of shear stiffness in the span direction of the vertical connection slab at both ends of the connection slab decreases,which increases the maximum two-way displacement angle by 20.05%,4.20%,and the two-way vertex displacement by10.26% and 4.86%.The damage of the connecting beam is more serious,the stress of the connecting plate increases by 161.82%,and it is easy to crack under large earthquake.3.The spacing D of the connecting plates,whether the connecting plates are open or not,and the setting density of the connecting plates have little influence on the overall response of the structure under large earthquakes.Increasing the setting density of the connecting plates can reduce the stress and cracking possibility of the connecting plates.(2)In order to further understand the difference of seismic performance between symmetrical and asymmetrical shear wall structures with weak connection slabs,the seismic vulnerability of symmetrical and asymmetrical shear wall structures with weak connection slabs was analyzed by quantifying the effects of symmetrical and asymmetrical two towers on the seismic performance of super-high-rise shear wall structures with weak connection slabs under different earthquake intensity.The results show that the exceeding probability of asymmetric structures under the three limit states of mild damage,moderate damage and severe damage is 10.40%,12.12% and 3.14% higher than that of symmetric structures under 8degree rare earthquakes.Moreover,with the increase of ground motion intensity from 0.07 g to 0.4 g,the difference of exceeding probability between asymmetric structure and symmetrical structure under the two extreme states of moderate damage and severe damage increases from 0.000% and 0.000% to 12.1281% and 3.1434%,and the difference of exceeding probability between the two extreme failure states increases with the increase of ground motion intensity.In a word,the asymmetry of the stiffness of towers on both sides of the structure will increase the probability of exceeding the ultimate failure state and decrease the seismic performance of the structure.(3)In order to avoid the serious consequences caused by the tension damage of the upper connecting slab and the chain damage of the lower connecting slab,the connecting slab at the higher floor is isolated.By changing the horizontal shear stiffness of lead rubber isolation bearings,the effects of different horizontal stiffness of bearings on the seismic performance of structures are studied.The results show that when the horizontal stiffness of bearings is set between 8000 kN/m and 16 000 kN/m,the stress level of the connecting plate is reasonable under large earthquakes,the horizontal displacement of the connecting plate is less than 200 m m,and the displacement angle between layers and the damage state of the whole structure are within a reasonable range.