Research On The Large Chassis Story-isolation Technology

The isolated structure is to set the isolation layer between the building superstructure and foundation to extend the natural period of the entire structural system,increasing the damping to reduce the seismic action to import to the upper structure,and to achieve the expected shock requirements. The large chassis story-isolation technology is the development and innovation of the isolated structure, immediately, It is the isolation technology used in a large chassis tower structure, and the isolation layer which has the isolation device is located between the large chassis and the tower or the top layer of the middle layer.The large chassis story-isolation technology has its own advantages,such as it could be used in adding layer reinforcement project of the existing structures,and it also could be used in some special structural which should not use the base isolation.Recently, it attracted widespread attentions by people, now it is used in the the actual projects.This article conducts the theoretical analysis of the the large chassis story-isolation structure.Discussing the establishment of the large chassis story-isolation structural dynamic analysis model, and establish the dynamic equations of motion of the structure corresponding to the knowledge of the structural mechanics. According to the difference of the location of the isolation layer, we proposed two simplified models, and establish the equations of motion. Combining the theoretical analysis and numerical simulation, we simulate to establish a18-storey single tower chassis shear wall structure (chassis is3layers, tower structure is15layers), use the software PKPM and ETABS to simulate and analyze the non-isolated structure, receiving the period and quality, comparing the two results, and confirm the correctness of the models.Using the ETABS to analyze the Isolated Structure, receiving the damping coefficient,specific content and conclusions are as follows:Set the isolation layer in the middle of the large chassis and the upper part of the tower structure as the base isolated structure, calculation the period,shear,displacement and damping coefficient under the EL Centro wave,the artificial wave.Use the damping coefficient to describe the damping effect of the structure.Increased damping of the isolation layer, calculate the damping coefficient under the EL Centro wave, compared with basic isolation structure, explaining influence of the isolation layer’s damping to the damping effect.Calculated the damping coefficient of difference position of the isolation layer, analyzed the result,optimize the design.Finally, this paper summarizes the results of research,draws relevant conclusions, and proposes the main content of further study which large chassis story-isolation structure requires.