The Influence Of The Collision Of Adjacent Isolated Structures On The Structural Performance Under The Action Of Earthquake

Due to the distance between adjacent buildings can not meet the requirements of relative displacement under the earthquake,resulting in lateral collision of adjacent buildings,resulting in structural damage or even collapse.At present,the reserved distance between some domestic buildings or the width of the anti vibration joint is not enough,especially for the isolation structure,because of the existence of the isolation layer,there will be a large lateral displacement,in case of strong earthquake,there is a great potential safety hazard.Meanwhile,according to the post earthquake investigation at home and abroad,the phenomenon of structural damage caused by the collision of adjacent buildings meet the eye everywhere.Therefore,it is of great significance to study the structural collision under the earthquake.In order to explore the impact of the collision of adjacent isolated structures on the performance of the structure under the action of earthquake,the following aspects are studied in this paper:(1)In this paper,the common methods used in the study of collision problems,such as collision dynamics method,contact element method and Lagrange multiplier method,are described,and the corresponding collision models of contact element method are introduced in detail.The calculation formula,application,advantages and disadvantages of each model are summarized,and the Hertz damp model is selected to simulate the research content of this paper.In addition,the Newmark-?method,which is used to solve the dynamic equation of adjacent structures,is briefly introduced.(2)In this paper,an isolated structure and its adjacent non isolated structure are simplified into a single degree of freedom system,and ten strong earthquake records are selected to calculate the impact spectrum in the elastic range.The impact of different parameters on the impact spectrum is studied.The research shows that the smaller the initial spacing and damping ratio of adjacent structures is,the greater the collision stiffness is,the more likely the collision phenomenon will occur,and the greater the impact of collision on the structure will be;different seismic waves have different impacts on the collision of adjacent structures,with great differences;the peak acceleration of seismic waves has a great impact on the collision of adjacent structures,and the larger the PGA,the greater the impact between adjacent structures The greater the probability of collision,the greater the ratio of collision force,acceleration and displacement to the original response spectrum.(3)In this paper,four types of isolation structures,one is the isolation structure with the isolation layer in the upper,the middle and the lower,and the other is the base isolation structure,which are respectively simplified to a multi free system with an adjacent non isolation structure.Three records of ground motion are selected to calculate the time history of collision force,acceleration and displacement in the elastic range,and the parameters affecting the collision of the structure are analyzed.The results show that the impact makes the structure produce larger acceleration pulse and amplification effect,and the acceleration values at the impact position and the isolation layer are larger.When the isolation layer is set at a high position,it has a better isolation effect at the time of impact;the displacement of the base isolation structure is the largest,after the impact,the displacement of the isolation structure and the non isolation structure increases;with the increase of the period ratio,the displacement of the isolation structure and the non isolation structure increases With the increase of the initial spacing,the maximum impact force and impact acceleration ratio of the structure decrease;with the increase of the impact stiffness,the maximum impact force and impact acceleration ratio increase.