Study Of Application Of Strengthened Stories In High-rise Building Structures

The shear lag effect caused by the flexibility of the spandrel beam inflects the vertical stress distribution curve of the columns of web and flange frames in frame tube structures, which is called as the stress concentration phenomenon of corner column. The shear lag effect significantly weakens the spatial performance of the frame tube structures and lowers its ability to resist lateral loads. Given that setting strengthened storey could reduce the shear lag effect, it has been extensively regarded and employed all over the world. Many researchers studied and optimized this structural type long before and a lot of achievement has been obtained. But most of these efforts has been directed to secure the optimal location of the strengthened storey with different simplified models. By changing the stiffness and the arrangement of the strengthened storey in some engineering case, the influence of the strengthened storey on the structural performance is studied in this dissertation.The optimized location is testified through linear static analysis. In the case that the strengthened storey is only set at the top of the structure, the increase of the bending stiffness of the strengthened storey could notably weaken the shear lag effect when the ratio of the bending stiffness of the strengthened storey to the axial stiffness of the mid column is less than 1.25m~2. But when the ratio is greater than 1.25 m~2, this effect is negligible. The optimal location for lowering the shear lag effect of structure with single strengthened storey is approximately at one sixth of the total structural...