ABSTRACT
This chapter focuses on one special mortise and tenon joints in Chinese multi-layer timber structures, the composited column joint (JCC). The JCC is a common joint in traditional Chinese multi-layers timber structure. Firstly, an ultrasonic detection was carried out and three problems were found. The first problem is the ultrasonic probe cannot offer enough accuracy with round column. The second is the feedback wave is hard to describe 3d-form. The third problem is the hardness to figure JCC position. The JCC iron-enforced had an additional broken iron hoop. The iron hoop itself did not fail. But some bolts were pushed out. The craft of joint is quite random and the buildings were kept safe, even under some serve earthquake. Former analysis pointed out that though many different failures were included in the joint failure. The key one is the crack in end stages.
