Research On The Application Of Novel Ring Spring Support For Metro Vibration Isolation

As an important means of alleviating the pressure of urban traffic,the subway not only brings convenience to people's lives,but also brings noise and vibration pollution to the subway roof and neighboring residents.The environmental vibration problem of the subway will not only reduce the comfort of the building,affect human health and the use of sensitive instruments,but seriously affect the safety of the building.For this reason,this paper studies the vibration isolation of the subway superstructure and surrounding buildings.Using the vibration damping capacity and self-reset function of the thick-walled ring spring,a new type of vertical vibration isolation support is developed for the building base isolation.The main content of the paper is as follows:(1)The vibration response of the subway in the free field along the Guangzhou Metro Line three was measured on site,and the time-history data of the vertical vibration acceleration was obtained.A spectrum study was conducted to find out that the dominant frequency of subway vibration is 30 ? 50 Hz.The propagation law of ground vibration caused by subway operation was studied.The propagation law of ground vibration caused by subway operation was studied,and preliminary environmental vibration assessment was carried out for Line 3,and the database of subway vibration excitation was also enriched.(2)Theoretical research is performed on the mechanical properties of thick-walled ring springs,including the structural characteristics,static performance and dynamic performance of ring springs.The calculation formula of the maximum tensile stress of the outer ring of the ring spring is derived in detail.The thick-walled members are corrected and supplemented,and the finite element is used for verification.The design of the ring spring is illustrated through a typical calculation case.The area of the thick-walled ring spring due to internal and frictional energy consumption during work is about 55% of the work performed.(3)Two finite element models of ring springs were established using ABAQUS.The static load test simulation and the dynamic load test simulation were performed,and the theoretical results and test results were used to verify each other.The stress distribution and loaddisplacement curve of the ring springs are obtained by simulation,and the mechanical parameters such as the bearing capacity,vertical stiffness and equivalent damping ratio of the spring were calculated.The effects of loading conditions on the mechanical properties of the spring were investigated,and it was concluded that the energy dissipation capacity of the ring spring increases with the increase of the preload displacement and the loading amplitude,and the acceleration transmission rate of the vibration of 30-50 Hz is about 0.2.(4)Taking a six-story frame structure as an example,a thick-walled ring spring was applied to the building vibration isolation,and the dynamic research of the ordinary structure and the vibration isolation structure under the vibration excitation of the subway was carried out.The vibration responses of subways with two structures are compared,and the time history and frequency spectrum of acceleration,the vibration isolation rate and displacement of spring are analyzed.The thick-walled ring spring vibration isolation support can prolong the structural period,effectively improve the building comfort,reduce the vertical acceleration by 50%,and the average floor isolation is 37%.