SEISIMIC ASSESSMENT OF A CIRCULAR LIQUID-CONTAINING CONCRETE STRUCTURE

Abstract

Large size circular liquid-containing structure is one of the most important infrastructures in water supply service. In Thailand,several of them have been constructed before implementation of the national seismic regulations. This paper proposes procedures for seismic assessment of the existing circular liquid-containing concrete structures. The first part of the analysis is to estimate the sloshing force acting on the structure induced from oscillation of water during earthquake. The fundamental of coupling of finite volume and finite element method, coupler Eulerian Lagrangian (CEL) are applied. To analyze the hydrodynamic force from sloshing, penalty contract algorithm is used in 3D model and column of the clarifier is modeled as a single column, stiffness equivalent to the stiffness of the clarifier. The second part is an analysis of the supporting structures subjected to the sloshing force by using linear time history analysis. Ground motions corresponding to the design response spectral in Zone 5 of DPT 1301/1302-61 are used for analysis. The selected ground motions correspond with the Conditional Mean Spectrum (CMS) at 0.2, 0.5 and 3.0 second. The results of this research demonstrate the applicability to model the force transfer from finite volume into a single column under seismic load by comparing with the model of water sloshing. The on-going research is to evaluate the safety of the structure from the earthquake response.