Seismic action and structural safety of urban landscape sculptures

The seismic action of urban landscape sculptures is very closely related to the structural safety. According to the records of seismic data, the dynamic characteristic analysis of the statue structure shows that about 5 million recordable earthquakes occur around the world every year, among which 50,000 are felt earthquakes and nearly 1,000 cause damage. And on average, more than ten strong earthquakes of magnitude 7 or above, which are capable of causing heavy damage, occur every year.

The seismic action has a great impact on the structural safety. High - rise buildings are particularly sensitive to earthquakes because as the height of the building increases, the influence of horizontal loads on the structure also becomes greater and greater.

For example, the bronze colossus of Apollo, built in 282 BC, was located at the entrance of the port of the island of Rhodes in Greece. The white marble base of the colossus was hollow, and the body was made of bronze and was 3m high. A strong earthquake in 225 BC severely damaged the statue. The weaker parts were shattered and it was never repaired again. Earthquakes are closely related to the dynamic characteristics of the structure itself. The changes in the mass and stiffness of the structure will directly affect the intensity of the seismic action.

Therefore, the code requires that the plane and elevation of the building should be arranged as reasonably as possible during the design. However, for large - scale statue structures, since the irregular shape cannot be artificially changed, the center of mass often deviates seriously, and the aspect ratio is much larger than that of ordinary high - rise buildings. Therefore, their dynamic characteristics are also very different from those of high - rise buildings. For this reason, this chapter takes the project of the Thousand - Handed Avalokitesvara statue in Changsha as an example, according to the characteristics of this type of structure, and introduces how to carry out the calculation and analysis of the dynamic performance of large - scale statue structures with an extremely large aspect ratio using the mode - decomposition response spectrum method and the time - history analysis method in accordance with the code requirements.