| Among the main structural systems of super high-rise buildings, tube is widely used of domestic and foreign. Considering the economic and functional points of the building, the frame-core wall structure is more adopted by people. The perimeter frame columns of frame-core wall structure usually adopt the column frame in dilute, sometimes the sway can not meet the normative requirements under wind or seismic role. On account of this situation, the frame-core wall structure with strengthened stories was proposed by the Canadian Barbacki in 1962. After decades of development, this structural system has been used in a large number of high-rise buildings by engineers. However, the adverse effects of the structure caused by the strengthened stories such as the mutation of the lateral stiffness, cutting off the level traffic problems have stilled not been solved well. And the design terms from the design specifications for the structures are too simple in our country. Therefore, it is quite necessary to do more study of the structure system with strengthened stories.Based on the present researching and mechanism of strengthened stories and combined with the practical engineering, this paper did some work for the adverse effects of the structure by the strengthened stories as follows: To achieve the strengthened stories set in general floors and connected with the inner cylinder easily, it provided the reactive powder concrete(RPC) to the outrigger of vierendeel truss and the surrounding annulus member. It also designed more than ten schemes with different materials, different location and numbers of strengthened stories for practical engineering and carried out a detailed comparison for the effect of the various programs. To reduce the mutation of the lateral stiffness, this paper proposed the design idea of strengthened stories with small stiffness and verified its feasibility. We can get following conclusions based on the research work.(1) Compared with NC vierendeel truss strengthened stories, RPC vierendeel truss strengthened stories has more obvious advantages, including control of the period, lateral and inter-story displacement angle of structure, the effects of the latter are better than the former. To ensure the same indicators of structure, RPC strengthened stories can reduce the member section of outriggers significantly, reduce structural weight, and provide more building spac e, thus avoiding an impact on the level traffic with good applicability.(2) The reduction of structure attributes such as cycle, lateral were increased with the increase of strengthened stories number, but with the amplitude of strengthened stories decreases with the increase of the number, this is the similarity of all conventional strengthened stories, but as an increase in the number of RPC strengthened stories, the attributes such as cycle, lateral can still maintain a certain range of diminution.(3) The top floor without strengthened stories of schemes, whose the control effect of cycle, lateral and other structure attributes is superior to the top floor with strengthened stories as the same conditions, but the degree of structural lateral stiffness mutation is more significant. When only one strengthened stories is set, it should not be set on the top floor, because it can enhance the torsion effect of structure, adverse to the aseismic.(4) Small stiffness strengthened stories still can control the structure properties such as cycle, lateral, by avoiding the case of structural lateral stiffness mutation, thus proving that the small stiffness strengthened stories is feasible. |
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