Experimental Research on Key Joints of Shanghai Tower

Shanghai Tower is the tallest building in China under construction. The superstructure of the tower is composed of a central reinforced concrete shear wall core and composite steel reinforced concrete (SRC) mega-columns through outrigger trusses, as well as belt trusses which are placed around the perimeter of the building at the levels of outrigger floor. As two major types of key connections, the JDA-Joints (composed of SRC mega-column, mega-outrigger and belt truss) and the JDB-Joints (composed of mega-outrigger and reinforced concrete core wall) shall play a significant role in transmitting loads and connecting members. The monotonic and hysteretic behaviour of these two kinds of connections were investigated experimentally in this paper. A loading system which could apply multi-direction loads in several points was designed. Details are presented such as test scheme, test set-up, instrumentation and test process. It is shown that all joint specimens can connect the adjacent components effectively and transmit loads reliably under the design and severe earthquake loading conditions. It can also be seen that both the two kinds of joints have good deformation ability under static loads and good energy dissipation ability under hysteretic loads. During the tests, local buckling and plasticity of outrigger web members were developed obviously which indicates that the strength of joint zone is much higher than that of other members. The tests also make known that all specimens meet the design requirements, and the conclusions of the tests can provide guidance for design.