| With the rapid development of urban rail transit in China,the urban space development mode oriented to rail transit hubs has gradually become the mainstream development mode in large cities.Currently,the operating mileage of urban rail transit in China exceeds the total mileage of other countries,and it is expected to reach about five times the current level by 2035.The vibration disturbance caused by subway operation is becoming increasingly prominent and even seriously affects the functional use of buildings.Furthermore,many TOD buildings adopt complex conversion structures,and many are located in emphasis zone for monitoring earthquakes with high seismic requirements.In this context,a large number of TOD buildings are facing the double threat of traffic vibration and earthquakes,which seriously restricts urban development.Inter-story isolation,as a new development of isolation technology,is a recognized technical means that can effectively control the influence of vibration and prevent earthquake disasters.In this thesis,a dual-control of vibration and seismic inter-story isolation strategy is proposed for the typical structural form of TOD buildings.The full-frame support inter-story isolation system of TOD building is formed by this scheme,which forms the environmental vibration isolation mechanism in the vertical direction,and the nonlinear energy sink mechanism in the horizontal direction.The inter-story isolation structural system of TOD building is studied through theoretical analysis,numerical simulation,and material experiments.The main research contents are as follows:(1)A full-frame support inter-story isolation structural system for TOD buildings using the dual-control of vibration and seismic scheme is established.The isolation layer has cubic nonlinear stiffness in the horizontal direction.The structural system is modeled by a simple three-degree-of-freedom model.A minimization objective function for optimal design of the system is proposed,and the relevant parameters are optimized.On the basis of the optimal parameters,the control performance and mechanism of the system are analyzed by using the theory and method of nonlinear energy sink.The results show that under the 30 mm limit,the TOD inter-story isolation structural system with nonlinear restrainer can effectively reduce the seismic response of the substructure of the system,and the mechanism is mainly the wide band internal resonance of the nonlinear energy sink formed by the isolation layer.(2)A rubber nonlinear elastic restrainer with cubic nonlinear stiffness was designed,which can be combined with the isolator to realize the nonlinear stiffness of the isolation layer in the horizontal direction.The structure and limiting mechanism of the device are introduced,and the compression performance test of rubber spring pads with different stacking layers and stacking methods was conducted for displacement control,and the force-displacement curve of the specimens under compression was obtained and compared with the proposed cubic stiffness nonlinear restoring force model.The experimental results show that the restrainer has nonlinear elasticity and certain energy dissipation capacity,which can meet the limiting requirements,and the proposed cubic stiffness restoring force model can describe the horizontal restoring force model of the restrainer properly.(3)Taking a real over-track building project in Guangzhou as an example,the inter-story isolation with nonlinear restrainer scheme was designed.The dynamic response of the finite element model of the structure is calculated by train-induced vibrations and seismic records,respectively,and the performance of the dual-control of vibration and seismic scheme is analyzed.The results show that the inter-story isolation system with nonlinear restrainer can effectively reduce the train-induced vibration and earthquake response of the TOD structure,and can effectively limit the horizontal displacement of the isolator under severe earthquakes. |
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