Ancient Chinese timber architecture. I: Experimental study

As an important part of the civilization in China, ancient Chinese architecture has an indigenous and unique system of construction that has retained its principal characteristics from prehistoric times to the present and spread its influence to other countries such as Korea and Japan. With the exacerbating environmental encroachment and time impacts that have been reducing their structural resistance, it has become imperative to preserve this architectural heritage. To provide the basic characteristics of the timber structures as fundamental information for research and preservation, on-site measurements and model tests were conducted on the front tower over the North Gate of the Xi'an City Wall. In the full-scale on-site tests, the vibration modes of the tower were measured. The first four natural frequencies of the structure were found to be 1.10, 1.70, 2.73, and 3.10 Hz, respectively. Multipoint excitation tests on wooden and polymethyl methacrylate (Perspex) models validate that the first and second modes obtained by the on-site full-scale test are the vibration modes of the tower. Many other valuable data and information were obtained through the tests, such as the damping ratio and the hysteresis curves.