FORMULAE TO PREDICT SHEAR STIFFNESS AND YIELDING STRENGTH OF HORIZONTAL DIAPHRAGMS REINFORCED WITH SHEAR KEYS ALONG PANEL JOINTS

Three kinds of simplified formulae to predict shear stiffness and yielding strength of a horizontal diaphragm reinforced with shear keys along panel joints are derived in this paper. The validity of these formulae is discussed based on the comparison of them to numerical analyses. It is shown that their validity depends on the ratio C of the stiffness of nails to that of shear keys.The shear stiffness and yielding strength of a horizontal diaphragm are the best predicted when the fact that the diaphragm behaves as a single panel for a higher C value is considered.