Connection bridge effect on a DNA-like two-spiral-up-tower building

In the recent years, more and more great ideas about architectural design were inspired from bionics, that is, the China National Stadium, Taipei 101, and India Lotus Temple were first inspired from bird's nest, bamboo, and blooming lotus, respectively. However, being a feast to the eyes, those innovative architectures with complex structural behavior and unknown seismic performance are always being a challenge to structural engineers. Hereinafter, a DNA-like high-rise building with two separate spiral-up towers was first outlined, in which each of the tower consist of an interior reinforced concrete core with inserted steel columns and an exterior composite frame made of steel beams and steel pipe–concrete columns. To study the influence of the connection bridges on the seismic performance under different level of earthquake excitation and torsional effect under gravity load, the load transfer mechanism of vertical force and lateral force was conducted, and a finite element model was built with parametrical studies. It can be concluded from the results from the parametrical studies that the drift angle was sharply decreased at the locations where the connection bridges combines two single towers, indicating that the lateral confinement effect of the connection bridges not only strengthen the whole structure but also leads to a discontinuity of the structural stiffness.