Design for the reconstruction of super high-rise building for Dalian New World Tower

The reconstruction of a project may cause the changing of the structural system, because new functions may be added and the plan may be altered. The issues concerned by designers are: (1) the codes applicability for new and old design may be different; (2) the connection between new part and old part need to be checked; (3) the interaction between the new and old towers need be to handled. After rechecking the primary design and inspecting the constructional conditions, the existing structure is assessed based on current and old seismic design codes. It is found the existing structure can not satisfy the requirements of current codes in carrying capacity. Therefore, concrete-filled steel tubes are used to reduce weight and strengthen the structure integrity, and some reinforcement measures are implemented. In the existing built part, the number and location of strengthened story and the form of transfer truss are optimized. As a result, outriggers are set at the strengthened story of 15, 26, 37, thus inter story drifts satisfy the requirements of new codes.