Study Of Mechanical Behavior Of Different Isolation Devices Selection For High-rise Frame-supported Frame-shear Wall Isolated Structure

High-rise frame-supported shear wall structure has a wide range of uses in practical engineering.However earthquake-resistance performance of the structural bottom is poor.The mature development of seismic isolation technique is applied in China and abroad,which changes high-rise frame-supported shear wall structure into high-rise frame-supported frame-shear wall isolated structure. Due to setting isolation devices, seismic wall will be discontinuous and isolation devices become supporters of superstructure. The safety of transfer components, seismic wall, reinforced parts of seismic wall and substructure prove to be outstanding problem in the isolated system owning to large displacement of isolation devices under earthquake.A typical high-rise frame-supported shear wall structure is chosen as analysis example.Through the seismic time history response analysis, the damping effect of the structure with different isolation devices selection scheme is compared by using software ETABS. Seismic force and deformation characteristics of substructure of isolation layer, isolation layer and superstructure of isolation layer is studied;the effect of shear wall discontinuity on the local response at isolated structure is investigated; seismic force of transfer beam from seismic structure and isolated structure is analyzed.Through the above analysis,some results and conclusions are obtained:1) If the stiffness about the level of isolation layer is reasonably chosen, earthquake reaction of the high-rise frame-supported frame-shear wall isolated structures can be effectively reduced, no matter which kind of isolation bearing arrangement.2) Based on the comparison of the overall mechanical of isolated structure, earthquake reaction of under different isolation devices of the structure has some differences. Whenselection of a large number of small bearings,the displacement of isolation layer and the angle of the superstructure above the isolation layer is larger,easily exceeding the standard limit value. Compared with the larger bearing arrangement scheme, the medium-sized bearing arrangement scheme, can effectively control the seismic response of the isolation layer and the superstructure, to improve the safety and economy of the isolated structure.3) Based on the analysis of internal force and stress of seismic wall, the internal force can be reduced and the stress distribution improved after setting isolation layer. owning to the bigger different stiffness between isolation layer and the adjacent, and the vertical discontinuous shear walls, the isolation layer and its adjacent floors have a more complex internal force. Furthermore, the fracture and the outside of the isolation layer appear larger stress concentration. The local with larger stress of the components which receiving complex forces such as seismic wall fracture or node core area, should be strengthened according to the actual stress distribution, and the weak point should be reinforced by structural measures. In addition, if the isolation layer adopts reasonable bearing selection scheme, the stress concentration of vertical discontinuous seismic wall can be avoided.4) Based on the study of seismic force of transfer beam from seismic structure and isolated structure, internal force of transfer beam under earthquake has reduced when setting isolation layer. Larger positive bending moment generated by the wall legging in the span of the transfer beam,will make the section of beam very large, which is designed according to the bearing capacity limit state, and there is a large shear force at the end of the beam. The method of adding the armpit should be used to strengthen the end part of the transfer beam.When the structure designed, the shear wall should be avoided to be arranged in the span of the transition beam, can be arranged at the end of the beam and directly supported on the frame support.