We've examined steel encased reinforced concrete buildings whose column bases were severely damaged due to 1995 Hyogo-ken Nanbu earthquake. We've deduced the tension force due to overturning moment has caused these damages through statistical analysis of the data. We've also proposed the models to estimate the shear coefficient C_B equivalent to the overturning strength of the building Those buildings which suffered severe damage at their column bases had C_B values less than 0.5 and/or had C_B value lower the shear coefficient C_O values which are estimated summing the shear strength of the columns and walls. Those buildings whose tensile strength of the column base overwhelms that of the column itself could also avoid the damage of the column base.
