| In recent years,with the increasingly tense urban land,there have been some examples of successful development of the upper space of the metro platform in China.However,as a special structural form,this type of seismic design and construction of the project is often faced with many difficulties different from the conventional construction.In particular,since the seismic intensity map of China was changed in 2016,the seismic design requirements have been improved.Seismic design of new structures on the subway or rail transit platform structures is getting more difficult.Moreover,due to the restrictions of the subway line and its normal operation requirements,it is usually difficult to take reinforcement measures for the original large platform structure.The use of seismic isolation technology as the first choice to solve this problem,that is,according to the characteristics of the superstructure,or the use of energy dissipation dampers in newly built structures,to reduce the seismic effect of the superstructure through energy dissipation methods;or to use laminated rubber seismic isolation technology reduces the impact on the structure of the lower large platform by reducing the seismic response of the upper structure through isolation.This article analyzes and compares the advantages and disadvantages of these two methods through practical cases.1.The state of art of energy dissipation technologies and isolation technologies at home and abroad was reviewed.The energy dissipation and shock absorption of displacement steel hysteresis dampers,and the principle and application status of interlayer vibration isolation using rubber isolation technology were highlighted.On the basis of introducing the background of the topic selection,this paper proposes the research contents of applying energy dissipation,shock absorption and seismic isolation technology when developing new structures on the subway or rail transit platform structure.2.Taking a residential project in the Ningbo metro depot as an example,the difficulties encountered in the seismic design of the residential building frame structure over the large-scale structure of the subway when the project is increased from 6 degrees to 7 degrees are described.By using the steel hysteresis damper device,the G4 building was used as an example to analyze the system’s shock absorption.The effects of energy dissipation and shock absorption were discussed.Through performance analysis and design,the reinforcement scheme on lower cover structure with the used of energy dissipation devices is given.3.Taking an employee dormitory project in the Ningbo Metro Depot as an example,the optimization of the earthquake-isolation solution for the high-rise frame structure built on the large-capped metro structure was studied using laminated rubber isolation technology,from component reinforcement to axial compression ratio.The displacement responses of the upper and lower story of the strata are systematically compared and analyzed to determine whether the over-limit details of the existing cover structure of the earthquake-isolation scheme are adopted;the shock-absorbing effect of the seismic isolation is discussed in detail,and the seismic isolation design scheme is determined.Through the performance analysis In contrasts the reinforcement of the lower cover structure was determined.4.This paper compares and analyzes the advantages and disadvantages of the above two projects by using energy dissipation technology and seismic isolation technology to deal with the added structure above the large cap of the metro,and gives recommendations.The theoretical analysis shows that the seismic isolation scheme is generally better than the shock absorption scheme.The seismic isolation system has good seismic performance,can reduce the amount of reinforcement of the lower structure,has good economic values,and has broad application and promotion value. |
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