Shear Strength Prediction of Eccentric Beam-Column Joints

摘要

Several studies showed that the eccentricity between beam and column connections has a detrimental effect on the joint shear strength. With regard to this issue, ACI 318-08 restricts the average shear stress on a horizontal plane within the joint, which equals to the effective joint width times column depth. The formula of effective joint width given in ACI 318-08 may be too conservative for eccentric beam-column joints. This paper suggested a more rational formula of effective joint width associated with the softened strut-and-tie (SST) model for eccentric beam-column joints. Using the proposed effective joint width, the shear strength predictions of SST model agreed well with the results of 18 eccentric joint specimens failed in shear. Furthermore, together with the proposed effective joint width, several available definitions for effective joint width are also used as comparisons to estimate joint shear strength of collected database for eccentric and concentric joints using ACI 318-08 code design equation. The proposed effective joint width was successfully verified with available database of beam-column joints with or without eccentricity in literature.