رفتار لرزه ای یک دیوار برش کامپوزیتی نوآورانه
Abstract
1- Introduction
2- Experimental program
3- Cyclic loading tests
4- Load-carrying capacity
5- Conclusions
References
Abstract
To improve the strength and ductility of the core walls in high-rise buildings which would be subjected to combined high axial compressive force and bending moment during the earthquake, an innovative concrete filled double-skin steel-plate composite (CFDSC) wall is proposed. The CFDSC wall is composed of the concrete filled double-skin steel-plate wall body with transverse stiffeners, vertical diaphragms and distributed batten plates welding on the internal surface of the double steel plates, and the concrete filled steel tube (CFST) columns including a pair of CFST columns positioned at the end of the cross section as boundary elements and an additional one located in the central section of the wall. Five CFDSC wall specimens were tested under constant axial compressive force and lateral reversed cyclic loading to investigate the seismic behaviour of the wall considering the effect of axial force ratio and shear span ratio. The favourable seismic performance of the CFDSC walls was demonstrated in the test. No serious pinching effect was observed on the hysteresis curves of all the specimens. The drift ratios corresponding to the ultimate stage were recorded as being in the range from 1/67 to 1/30 and the ductility coefficients were varied from 4.50 to 8.22. The experimental results manifest that the CFDSC walls have great energy dissipation capacity. Formulae for calculating the lateral load-carrying capacity of the CFDSC wall, taking the confinement effects from steel plates into account, were proposed. The results calculated by the proposed method show good agreement with the experimental results.
Introduction
The reinforced concrete (RC) shear walls are critical structural components to resist the lateral force in high-rise buildings. In recent years, constructions of high-rise buildings are increasing rapidly in China, while the conventional RC shear wall might not be able to provide sufficient resistance to the seismic loading combinations, particularly for the walls located at the lower stories which are usually subjected to substantial axial compressive force and bending moment. To satisfy the seismic design requirement of high-rise buildings in earthquake zone, the concrete filled double-skin steel-plate composite (CFDSC) wall, which consists of two steel faceplates on the exterior surfaces and the infill concrete, is becoming increasingly attractive as the main lateral resistance component. The CFDSC wall takes advantages of both RC wall and steel plate wall [1]. The infill concrete could prevent the concave local buckling of the steel plates, and thus improves the anti-local buckling capacity of the steel faceplates, while the strength and ductility of the inner concrete are enhanced due to the confinement from the outer steel plates. By the reason of its excellent mechanics performance, the thickness of CFDSC wall could be much smaller than that of the conventional RC wall, which could reduce the weight of building and increase the usable floor area [2]. Furthermore, the construction process of the CFDSC shear wall is also quite efficient since the steel faceplates could act as permanent formwork. It has been proved that the CFDSC wall performed high lateral resistance and excellent energy-dissipating capacity, and thus has been adopted in several high-rise buildings to replace the traditional RC shear wall.