Seismic Performance Analysis Of Multi-tower High-rise Structures With Full Frame Support And Thick Plate Conversio

With the increase of urban development and social production and life demand,urban land resources shortage and traffic congestion come one after another.At present,the development and utilization of metro rolling stock depot can alleviate the shortage of urban land and generate economic value,thus becoming a research hotspot.In order to meet the daily use function of vehicle depot,it usually needs large span and space and avoids the vertical components of superbuilding extending to the bottom of the structure.In recent years,the new structural system of full-frame supported thick plate conversion high-rise structure has been applied in practical engineering projects because it can better meet the development requirements of vehicle depot.However,the research on this structural system has not been in-depth yet.The analysis of its seismic performance is not mature enough and needs further study.This paper takes the fullframe thick plate conversion high-rise structure of a metro rolling stock depot as the research object,and studies the seismic performance of this system structure by combining shaking table test and finite element simulation.The specific research contents are as follows:1.In order to study the seismic response rule of multi-tower high-rise structure with fullframe supported thick plate conversion under earthquake action and reveal the influence rule of different tower number and arrangement on structural dynamic characteristics and response,single,double and three-tower models were established based on the full-frame supported thick plate conversion high-rise structure of a metro rolling stock section,and the shaking table test of steel structure and other generation models with 1:35 scale ratio was carried out.According to the test data,the vibration table model can better reflect the dynamic characteristics of the original model,and the maximum frequency error between the test model and the original model is 8.54%.2.By comparing the experimental data of each model,it is found that with the increase of the number of towers,the structural frequency decreases slightly,and the difference of the firstorder frequency between the single-tower model and the three-tower model is only 3.44%.After adding the tower,there is a large eccentricity of centroid between the full frame support and each tower,which results in the ground motion response of the multi-tower model is higher than that of the single-tower model,while the two-tower model has the highest seismic response due to the obvious asymmetry of the design,which leads to the strong plane-torsion coupling reaction.As the number of towers increases,the strain of the columns closer to the tower increases,and is higher than the tower strain.3.In order to study the seismic performance of the multi-tower structure system affected by the change of plate thickness,transfer layer height and total structure height,three groups of9 models were established based on the finite element model of three towers by changing the thickness of the transfer thick plate,the location of the transfer layer and the total structure height respectively,and the dynamic characteristics of each model and the dynamic response under rare earthquakes were analyzed.The results show that,for this kind of system,the change of the position of the transfer floor and the total height of the structure has a great influence on the structure.The displacement and displacement Angle of the whole frame support floor increase with the position of the transfer floor,which is not conducive to the seismic resistance of the structure.The total height of the structure is increased,the natural vibration period of the structure is increased and the response of the tower is enhanced.The conversion thickness of the plate has little influence on the structure.When the plate thickness is increased,the structural displacement and interlayer displacement Angle will decrease slightly,but the shear force will increase accordingly.4.In order to optimize the simplified model of concentrated mass points,a parameter optimization analysis method of simplified model of multi-tower high-rise structure with fullframe supported thick plate conversion based on response surface method was proposed,and F-LMS models of each original model were established.By comparing the F-LMS model with the LMS model,the dynamic response of the FEM model was closer than that of the LMS model.The maximum cycle error of the single tower model decreases from 18.67% of the LMS model to 6.36% of the F-LMS model.The acceleration and displacement envelope values of the whole frame branch layer and T1 of the F-LMS model of all models are close to those of the FEM model,and the RMSE value of the F-LMS model is lower than that of the LMS model.It shows that F-LMS model is superior to LMS model in dynamic response simulation of FEM model.