Mechanical behavior of Chinese woven timber arch bridges

摘要

Chinese woven timber arch bridge is an important part of the precious cultural heritage handed down from ancient times. Its construction technology has been inscribed on the List of Intangible Cultural Heritage in Need of Urgent Protection by UNESCO in 2009, and twenty-two bridges of this kind have been listed in the tentative list of the Chinese World Cultural Heritage since 2012. Made by longitudinal and transverse straight logs woven together with mortises and tenon joints, the main arch is not a planar structure nor a general three-dimensional spatial one, and its mechanical behavior cannot be computed by the traditional structural analysis method. In this study, loading tests and FE analyses on the woven arch, and field tests and FE analyses on a really bridge are carried out. For the woven arch, two joint types, rigid and hinged joints are considered in the tests and analyses. The results show that: (1) the deflection shapes of woven arch models with rigid joints and hinged joints are similar; (2) the deflection of a hinged woven arch is larger than that of a rigid one; (3) the two systems of a woven arch can work together simply by the contact between them, but in some loading cases, some portions of them will separate and no force is transferred between them; (4) the mechanical behavior of the woven arch is similar to that of the two-hinged arch. In other words, it is also subjected to horizontal thrusts under vertical loads, but the compression force is the dominant one; and (5) the modeling method of the woven arch is applicable to Chinese timber arch bridges.