Abstract
The shear slip failure of unenbedded type column bases in SRC structures were reported by Hyogoken-Nanbu earthquake and the experimental research in recent years. However, there has been no study that tried to evaluate ultimate shear strength of unenbedded type column bases. We describe the structual test carried out in order to study ultimate shear strength and hysteresis property of unenbedded type column bases. Structural test made it clear that mechanical property depends on the axial force level, and the anchor bolts is not valid for ultimate shear strength. We proposed the evaluation method of ultimate shear strength. Ultimate shear strength of column base is calculate by applying the superposed strength method, in which the ultimate shear strength of the anchor bolts and friction between the base plate and the concrete below the base plate is taken to be the sum of the punching shear strength of the RC portion surrounding the base plate. Proposed evaluation method of untimate shear strength is in accordance with the test result well.
