Study Of Dynamics Coupling Effect And Performance-based Design Method Of Inter-story Isolated Structure

Inter-story isolated structure is recently research hotspot of seismic isolation in recent years,scholars at home and abroad has conducted a lot of work about story isolation structure. This paper studies the following contents:(1 ) With regards to simplified calculation of story isolation structure, this dissertation puts forward simplified mathematical model of systems of three particles and double particles, studies the dynamic property of simplified mathematical model of double particle system and seismic responses to sensibility of mass ratio and period ratio of models and infers the simplified formula of model parameters. There are great differences between both damps which make up non-proportional damp. It needs assessing the non-proportional damp's impact to realize mode decomposition. To solve the above-mentioned problems, this paper studied following work.(2 ) Torsion-lateral coupling analysis model of an inter-story isolated bi-directional eccentric structure under bi-directional earthquakes was established.The superstructure and substructure nonlinear properties have been considered. The biaxial force-deformation behaviour of the Lead Rubber Bearings (LRB) is modeled by Bouc-wen model by coupled non-linear differential equations. The influence of eccentric parameters on inter-story isolated structure was investigated. Numerical simulations were conducted to verify the accuracy of torsion coefficient formulate provided by Chinese Code for seismic design of buildings (GB 50011-2010).(3) In this paper, the dynamic equation of simplified degree of freedom system has been built by taking SSI effect's story isolation structure into account. Based on simulated SSI effect of disperse spring model, this dissertation established analytical model of simplified story isolation structure, analyzed and compared the far-fault and near-fault seismic wave with or without consideration of SSI effect on seismic responses of story isolation structure.(4) this dissertation established simplified three degrees of freedom system and energy equation of story isolation structure and investigated the relationship between energy ratio of high order mode and relevant parameter of mode. Based on the principle of energy balance, this dissertation proposed multi-modal simplified evaluation which is suitable for earthquake resistant behavior of story isolation structure. On the basis of multi-modal energy spectrum model, earthquake resistant behavior of story isolation structure is evaluated. By adopting model example, the validity and accuracy of this paper's methods are demonstrated. The influence of high order mode can be taken into consideration on computing method with less amount of calculation and good analytical precision of structure performance evaluation of strong earthquake.(5 ) this dissertation puts forward earthquake resistant design method of story isolation structure based on displacement. After two transformations, system with several degrees of freedom of story isolation structure is simplified into equivalent double degree of freedom model and equivalent single degree of freedom (ESDOF)system. Displacement ratio model of double degree of freedom story isolation model is established. The side force distribution pattern of story isolation structure and major parameters such as equivalent damping ratio and equivalent stiffness of single degree of freedom of story isolation structure are inferred. The design cycle of performance design method based on displacement of story isolation structure is given. Earthquake resistant design is completed based on displacement with regard to a story isolation structure project in high intensity area. Checking calculation of time-procedure analysis is conducted on the design structure. It shows the method is not only simply effective and but also in line with engineering design which can be applied into the performance-based design of story isolation structure.(6) When the isolation layer in inter-story isolation structure displaces too large under super intensity earthquake action, inhibiting device will be added to limit such displacement of isolation layer. This article takes the inter-story isolation structure of framed shear wall as example and chooses seven seismic oscillation records of ?class site to make non-linear analysis under earthquake action on both unlimited and limited structures. Then we make a research on the reserved distance and limiting rigidity of inhibiting device to the effect of inter-story isolation structure on seismic response with rear occurring earthquake action, and make anti-seismic evaluation on the inter-story isolation structure.