Structural design of continuing-constructed high-rise building of Haikong International Plaza

Originally, Haikong International Plaza was designed to be a 168 m-high office building, but the construction was broken in 1995, and continued in 2006 with the height increased to 190 m. The tested strength of concrete of vertical members is 45 MPa, far below the design strength of 58 MPa, and the steel bars were corroded badly. According to inspection results, the original structural system tube-in-tube system is maintained, but the reinforced concrete frame-tube beams were replaced by steel beams. Structural analysis was performed using SATWE and ETABS respectively, results indicate that design requirements can be satisfied. Pushover and time-history analysis are conducted to investigate the influences of higher order mode and the seismic performances. The main reinforced concrete members are strengthened with section enlargement method embedded with wire rope net-polymer mortar. To improve the seismic performance, the open-frame girders are replaced by inclined braces, which can resist earthquake action effectively.