| Triple friction pendulum bearing is a novel isolation bearing which is formed by four stacked concave sliding surface and a internal slider.In the earthquake,with the increase of displacement,the concave disk of the bearing slides in turn,so that the hysteretic performance of the bearing changes,showing different stiffness and damping characteristics.Through the rational design of triple friction pendulum parameters,the bearing can present reasonable stiffness and damper under multiple levels of ground shaking to satisfy multiple earthquake hazard levels.To study the performance of structure isolated with triple friction pendulum,the building isolated with triple pendulum bearing and the mechanical behaviors of the triple friction bearings are investigated through theoretical,experimental and numerical study,base reaction spectrum analysis of multi-story and high-story isolation building,the isolation reaction of high-story isolated building under the far-field and near-fault ground motions are investigated,the kinematic response analysis of high-story isolated building under the varied bearing parameter(the radius of sliding surface and friction coefficient)are studied.The main work are summarized as follows:(1)The building isolated with triple pendulum bearing and the mechanical behaviors of the triple friction bearings are investigated through theoretical,experimental and numerical study.Through the static equilibrium equation,the different stage hysteresis formulas of the triple friction pendulum are derived.The numerical simulation method of triple friction pendulum in OpenSees software are introduced.The kinematic equation of single story building isolated with triple friction pendulum bearings is derived by structure dynamics,which is extended to multi-story and high-story isolation buildings.The frictional properties of Teflon-steel interface under the effect of sliding velocity and bearing pressure are experimental investigated.Meantime the low cyclic loading test and sine wave loading test are conducted to investigate the mechanical performance of the triple friction pendulum bearing.Good agreement is observed between the numerical and experimental models,showing the effectiveness of proposed the method of numerical model and providing the reference of analysis of the kinematic response of triple friction pendulum in the future.(2)Base reaction spectrum analysis of multi-story and high-story building isolated with triple friction pendulum bearing.The isolation response of 12-story high-story structure and 6-story multi-story structure are investigated from the perspective of frequency domain.The structures are imputed in unidirectional ground motion,and the acceleration time history of isolation layer and the ground motion are transformed into acceleration response spectrum.The change of acceleration response of isolation layer and ground motion are comparative analysis,which are investigated to reflect the energy dissipation of building isolated with triple friction pendulum.(3)The isolation reaction of high-story isolated building under the far-field and near-fault ground motion are investigated.The selected far-field and near-fault ground motions are input to the high-story building isolated with triple pendulum bearing.The response of displacement of isolated layer,base shear and the absolute roof acceleration under the far-field and near-fault ground motion are investigated.The results show that the near-fault ground motion has great influence on the kinematic response of structure isolated with triple pendulum bearing compared to the far-field ground motion.The near-fault earthquake ground motions with fling step occurs a large isolator displacement.The near-fault earthquake ground motions with directivity focusing has a great effect on the absolute roof acceleration of isolated structure.(4)The kinematic response analysis of high-story isolated building under the varied bearing parameter(the radius of sliding surface and friction coefficient)are investigated.The researching study is focused on the effect of the radius of sliding surface and friction coefficient on the hysteretic behavior of triple friction bearing.The sensitivity of parameters of the dynamic performance of high-story isolated building under multiple levels of ground shaking(service earthquake,the design basic earthquake,the maximum considered earthquake)are studied.The results show that the parameter of triple friction pendulum has an great effect on the kinematic response of high-story isolated building. |
PDF Full Text Request