Mechanical Properties And Experimental Study On Short-pier Shear Walls In Medium And Small High-rise Buildings

The Short-pier Shear wall is a new type of structure to resist lateral loads in recent years. It has got wide use in medium and small high-rise buildings due to its fine anti-seismic ability and no extrusive part. Whereas, theoretical studies and design codes about short-pier shear walls are behind engineering practices, which affects the application and development of short-pier shear walls seriously. As a result, further theoretical analysis and experimental studies are extremely essential.Initially, the definition of short-pier walls is further studied. Studies show that the parameterζreflects the strength of piers, which is the accordance to distinguish shear walls from wall-frames. Whenζexceeds the limit [ζ], piers retrograde to flat columns. At this time, the structure doesn't belong to the shear wall category, but become a flat frame. Moreover, the short-pier wall is the lower limit of combined-pier shear walls. Thus according to the difference ofζ, combined-pier shear walls can be divided to two sections, i.e. short-pier and long-pier combined-pier walls, in which short-pier combined-pier walls are briefly called short-pier walls while long-pier combined-pier walls long-pier walls. Therefore, long-pier walls belong to the upper section of combined-pier walls and are connected to small-hole walls.Secondly, the influence of parametersαon the mechanic performance of short-pier walls is discussed. Analysis demonstrate that the parameterαreflects the strength of the linkage between piers. When the shape and dimension of the pier section are fixed, the value ofαreflects the height of the rectangular wall hole, between which there exist a inverse relation. With the increase ofα, the lateral stiffness and bearing capacity of shear walls raise while the peak displacement decreases. By means of theoretical analysis, the suggestion that for short-pier shear walls,αshould between 6 and 10.Thirdly, experimental studies are conducted for the mechanic performance of two eight-storey symmetric coupled short-pier Shear walls and experimental results are analyzed. Results show that the short-pier shear wall is a structure of strong-pier and weak-beam type. The link beam ruins before the pier is damaged. Consequently, the short-pier shear wall has a good ability for energy consumption and is an aseismatic structure system. When the value ofζis fixed, with the increase ofα, the lateral stiffness and bearing capacity of shear walls raise while the ultimate deformation capacity decreases. Totally, the aseismatic performance of short-pier shear walls is strengthened with the increase ofα.Considering a high-rise building twenty-storey with short-pier shear walls as the engineering background, a contrastive analysis is conducted for several plans and the appropriate structural program of short-pier shear walls for this engineering is presented;Finally, a contrastive analysis of several computing methods for the ultimate bearing capacity of eccentrically compressed members with reinforcements proportionally distributed along the height of the cross section is carried out. Studies demonstrate that present"Technical specification for concrete structures of tall building"is to some extent conservative when computing the ultimate bearing capacity of eccentrically compressed members with reinforcements proportionally distributed along the height of the cross section while present"Code for concrete structures"is more reasonable.Based on analysis above, some suggestions are brought forth for the design and study of short-pier shear walls in this paper.