2015/6/2 Behavior:Shear Lag Behavior:Shear Lag columns will be less. The stresses in the inner columnslag behind those in he omer hence eteshg Behavior:Shear Lag Load-Carry Because of the effects o and strength of thestructure nurve of the tube is mainly bending 0 Solution? Load-Carrying Characteristics of Limit Height of Tube Horizontal Strengthened Storey Height of Grade A: non-seismic200 m Height of Grade B system,which can decrease the storey drift and the top drift nete 本课件版权归作者所有，仅供个人学习使用，请勿转载。 3 2015/6/2 3  The stresses in the corner column will be greater than those from a pure tubular action, and those in the inner columns will be less.  The stresses in the inner columns lag behind those in the corner columns, hence the term shear lag.  Because the column stresses are distributed less effectively than in an ideal tube, the moment resistance and the flexural rigidity of a tubular building are much less. Behavior : Shear Lag  Dash line: ideal tube  Solid line: Framed tube Behavior : Shear Lag  Because of the effects of shear lag, it does not fully utilize the potential stiffness and strength of the structure, although a framed tube is highly efficient, Behavior : Shear Lag  Because of the effects of shear lag, it does not fully utilize the potential stiffness and strength of the structure, although a framed tube is highly efficient. Solution? Load-Carrying Characteristics of Inner Tube  The RC shear-walls form a closed inner tube located in the core region;  At the bottom of the structure, the inner tube carries large shear force, which causes that the deformation curve of the tube is mainly bending deflection;  The moment caused by lateral loads of the inner tube is comparatively small; Load-Carrying Characteristics of Horizontal Strengthened Storey  Horizontal strengthened storey is the storey with outriggers or belt mega-beams. These floors are mainly used as equipment floors with less available space.  The function of strengthened storey is to connect the inner tube and the outer tube to form a huge anti-lateral loads system, which can decrease the storey drift and the top drift.  Restrain and coordinate the deformation of the frame-tube and the core tube and eliminate the buckling of the slab. Limit Height of Tube Height of Grade A: non-seismic  200 m, 7 degree  150 m, 8 degree  120 m; Height of Grade B: Tube-in-tube, Frame core-tube non-seismic  220 m, 7 degree  180 m, 8 degree  140 m; 本课件版权归作者所有，仅供个人学习使用，请勿转载