Analysis Of The Effect Of Isolation Design On The Performance Of High-rise Building Structure

As an unavoidable force majeure,the earthquake often causes the collapse of a large number of buildings and buildings,causing a great threat to the safety of people’s lives and property.Minimizing the damage caused by earthquake to building structure is of great significance to ensure life safety and post-disaster reconstruction.With the development of isolation theory and technology,many innovative isolation devices have been applied in practical engineering.In 2021,The State Council issued the Regulations on Seismic Management of Construction Projects,encouraging the use of seismic mitigation and isolation technology in more projects to meet the requirements of gradually increasing seismic fortification structures.Because of the late popularization of seismic isolation technology in China,it is mostly used in low and multi-storey buildings or public facilities.With the implementation of "Building Isolation Design Standard",the application of isolation technology to high-rise buildings has a broad application prospect.In this paper,combined with practical engineering cases,the dynamic elastoplastic analysis of structures under rare earthquake and extremely rare earthquake is carried out by perform-3D and ABAQUS,and the difference of dynamic performance between nonisolated design structures and isolated design structures is discussed.The main contents and results of the study are as follows:（1）Firstly,the principle of foundation isolation is deduced by formula,and it is proved theoretically that isolation design is easier to reduce the damage of building structure caused by earthquake action than non-isolation design.（2）Combined with the actual high-rise engineering cases,respectively create nonisolation model,partial isolation model and direct isolation model;Two isolation models are analyzed.It is concluded that the selection and arrangement of bearings will affect the dynamic characteristics of isolation structures.（3）PERFORM-3D and ABAQUS are used for dynamic elastoplastic analysis of three high-rise structure models.The conclusion is that the base-isolation design has a significant improvement effect on the component damage,floor acceleration,floor shear,overturning moment and base shear of high-rise buildings.（4）IDA analysis was used to analyze and evaluate the vulnerability of five substructures of three high-rise models,and the conclusion was that the failure of isolation structure was determined by the shear damage of support;The direct method is more conservative than the partial method in superstructure design.The isolation structure is more likely to meet the performance level requirements of grade 3 and above,while the non-isolation design structure has serious plastic damage and low performance level after earthquake.（5）Based on the collapse vulnerability curve,the safety reserve coefficients of the three high-rise models with a collapse probability of 10% are 0.783,3.722 and 3.796,respectively.When the probability of collapse is 50%,the safety reserve coefficients are0.994,3.963 and 4.204 respectively.Isolation design is beneficial to improve safety reserve against collapse.