Study On Seismic Performance Of Vertical Irregular Frame Structures Considering Structure-soil-structure Dynamic Interaction

With deepening study of soil-structure interaction effects,more and more domestic and foreign research pointed out that under the seismic action between adjacent buildings it will produce interaction through the soil and when buildings spacing become closer this interaction will become more and more obvious.With the continuous growth of economy and population,China's construction land tense increasingly,dense group of buildings continued to increase,when the earthquake occurred the interaction between adjacent buildings will become unable to ignore,but seismic codes in our country did not consider structure-soil-structure dynamic interaction effects.Reinforced concrete frame structure is currently widely used in the high-rise building structure form,in order to meet the requirements of the current building structure,function and appearance,this framework also appeared in the various vertical irregular arrangement.Because the vertical irregular structure is prone to stress concentration and cause serious damage to the structure,the probability of earthquake damage is much higher than other forms of building structure.Although the structure design can meet the relevant requirements of the current seismic code,the influence of the structure soil structure dynamic interaction is ignored.This leads to an overall assessment of the seismic performance of the vertically irregular frame structures,which may increase the unknown risk of the structure.Aiming at the above problems,this paper selects the vulnerability of various damage reports and research points out the underlying and the existence of a large number of irregular and irregular middle layer two vertical irregular frame structure as the research object,the establishment of dynamic structure-soil-structure interaction finite element model by the finite element software OpenSEES,the dynamic elastic-plastic time process analysis of structures under displacement,acceleration and base shear,the interlayer displacement angle of macroscopic parameters to fully understand the dynamic characteristics of vertical irregular structure under two kinds of structure-soil structure dynamic interaction,the actual anti collapse performance of the comprehensive evaluation of structure-soil-structure dynamic interaction under vertical irregular frame the structure of the incremental dynamic analysis method,in order to improve the vertical irregular frame structure considering the structure properties of water-soil-structure interaction under the influence of Performance level desig.The main researches and conclusions are as follow:(1)In this paper,we find out the key influencing parameters of the structure soil structure dynamic interaction effect,and identify the most unfavorable arrangement form of the superstructure in the structure soil structure dynamic interaction model.A12 storey reinforced concrete frame structure is adopted as the research object.For structure-soil-structure dynamic mutual role model in surrounding and target structures of the spacing and the surrounding structure of the volume two of structure-soil-structure dynamic interaction effect plays a decisive role,using universal finite element analysis software OPENSEES on model structure into action elastic-plastic history analysis,from the macro structure of the target vertex displacement,vertex acceleration,base shear,the interlayer displacement angle parameter changes analysis structure-soil-structure dynamic interaction on the dynamic characteristics of the rule framework structure influence degree.The research shows that the dynamic response of the structure under the influence of the structure soil structure dynamic interaction is greater than the soil structure dynamic interaction and the foundation stiffness;When the distance between the adjacent structure and the target structure is 0.25 times the width of the target structure and the volume of the adjacent structure is 1 times of the target structure,the structure soil structure dynamic interaction efect can reach the maximum.(2)Exploring the performance changes of vertical irregular frame structure considering structure-soil-structure dynamic interaction under seismic.On the basis of the originally regular frame structure,two common in actual engineering frame structures of ground floor irregular and middle floor irregular which are poor in fragility and have a large number of vertical irregular have been designed.And in the case of structure-soil-structure dynamic interaction effect of maximum structure arrangement,OpenSEES has been used to do some dynamic elastic-plastic time history analyses on structure mentioned earlier for the differences of seismic response between irregular and regular fame structures and differences of seismic response of irregular fame structure under structure-soil-structure dynamic interaction,soil-structure dynamic interaction and rigid connection respectively.To study the structure-soil-structure dynamic interaction effect on the seismic performance of the vertically irregular frames depending the variation of macro parameters such as vertex displacement,vertex acceleration,base shear and inter-story drift ratio.The results show that the seismic responses of the bottom irregular and the middle irregular frame structures are larger than those of the foundation joints under the soil-structure dynamic interaction,and the structural-soil-structure interaction is more significant than that of the soil-structure dynamic interaction seismic response should be large.Under the influence of soil-structure interaction and structure-soil-structure interaction,the amplitude of the irregular structure's top displacement,base shear force and interlayer displacement angle are larger than those of the regular structure,while the bottom irregularity and the amplitude of the structure is larger than that of the middle irregular structure.For the vertex acceleration ofthe structure,the existence of the soil layer will make the response smaller,but the irregular structure is smaller than the regular structure.(3)Analysis of seismic behavior of vertical irregular frame structure based on earthquake vulnerability of structure-soil-structure interaction.Three kinds of frame structures with different irregularities and irregularities at the bottom of the study are analyzed for earthquake vulnerability analysis.Three kinds of structures are analyzed,ie,rigid soil-structure interaction,structure-soil-structure interaction and the effect of structure-soil-structure interaction on the seismic behavior of three different types of frame structures under different earthquake intensities are comprehensively evaluated from the probability level of the seismic susceptibility curve.The results show that under different ultimate failure conditions,the seismic vulnerability curves of the three kinds of frame structures are always slightly larger than those of the rigid connections in the case of soil-structure interaction,and the seismic vulnerability of the structure-soil-structure interaction.The soil-structure interaction will underestimate the failure probability of the vertical irregular frame structure beyond the different failure states,so as to increase the vertical failure probability of the vertical-irregular frame structure,thus increasing the vertical failure probability risk of damage to irregular frame structures.