SLIP VERIFICATION METHOD FOR THE FLAT-BOTTOM CYLINDRICAL SHELL TANK SUBJECTED TO HORIZONTAL AND VERTICAL GROUND MOTION

Abstract

This paper presents the slip verification method for the tank with the seismic magnification factors of both horizontal and vertical directions. The equation is derived from an analytical model for the tank slip including the effects of anchor straps and the responses to the ground acceleration in both directions. Since an application of the seismic magnification factors for the tank slip verification implicitly neglects the coincidence between the ground acceleration and responses to them which considerably affect tank slip behavior, two coefficients which express their coincidence are determined to compensate for the deficiency. Since relationships of the coincidence to their probability of occurrence are clarified, the design vertical ground acceleration and vertical response acceleration based on the allowable probability of excess are introduced to the slip verification method. The proposed method accurately approximates the slip commencement of the tank.