Some Issues And Improvement Suggestion On Isolation Design Of Building Structures

With the isolation technology, the base isolated structures has been widely used in practical engineering. Many rules for isolated buildings were added to Code for Seismic Design of Buildings (GB 50011-2001). It is found there are some questions worthy of researching during the practice of the structural desigen. This paper discussed about these questions made a more thoroughly. The main study questions read as follows.It put forward some more reasonable advices of improvement on the several problems existed in the base-isolated structure desigen. Considering the rules for vertical seismic effect of the the base-isolated building, and combining with features of PKPM, It put forward the partial factor of vertical seismic effect in PKPM. Considering errors of additional eccentricity, The simple method is proposed in calculation additional eccentricity. According to research about earthquake wave at home and abroad, and combined with the characteristics of base isolated structures, It put forward the proposition methods on earthquake wave for base isolated structure. The eccentric torsion of baseisolated structures can not be ignored, So the displacement ratio and period ratio should been used in isolation structure to control the eccentric torsion of the structure. By analyzing the force of the basements in isolated structure, It discussed about the design approach of the basements in isolated structure. According to the structural characteristics of base isolated structure, It discussed about the vertical shear wall of the basements in isolated structure.It put forward improvable advices to the problems of the base-isolated building detail structure. According to the structural characteristics of base isolated structure, The elevator in the base-isolated structures should made measures of preventing collision to the frame column. By analyzing the temperature stress of base-isolated structure, It put forward that the expansion joint spacing of base-isolated structures can increase. The isolation layer of the base-isolated structure is not in the same elevation, it is recommended to strengthen the structure connect. Discusses the specification of the isolating wall bearings spaced not more than 2.0m, It put forward that the Spacing of isolation bearing under shear wall in the base isolated structure should not be restricted.Based on the research about structure performance levels and performance objectives at home and abroad. The performance levels and performance objectives of base isolated structures are classified, The multi-class performance levels and fortification performance objectives are established on the base-isolated structure. And furthermore story drift and story acceleration which used as the controlled indexes for evaluating the performance of base isolation.The research results of this paper have important theory meaning and practical value on perfecting the base isolated structure, code revision in the future.