Based on stress transferring mechanism and resistance mechanism, the bearing and shear strength formulae of through beam type S beam — RC column joints with the transverse beams were proposed. It was assumed that beam - column joints were composed of inner and outer panel , and the ultimate strength of beam - column joints was obtained by superposition of the ultimate strength of both panels. In the inner panel, bearing failure was caused by prying action and shear failure was the compression failure of concrete struts surrounded by the flanges, transverse web and face bearing plates. On the other hand, outer panel was considered to be resisted by arch and truss mechanism. Particularly, arch mechanism was considered to be composed of two concrete struts based on the failure pattern of the joints. Predictions were shown to be in good agreement with the previous test results.
