CORRELATION ANALYSIS OF A REINFORCED-CONCRETE BUILDING UNDER TSUNAMI LOADS AND EFFECT OF MASONRY INFILL WALLS IN TSUNAMI RESISTANCE Anat Ruangrassamee 1 and Piyawat Foytong 2 1 Assistant Professor, Department of Civil Engineering, Chulalongkorn University, Bangkok, Thailand, fcearr@eng.chula.ac.th 2 Graduate Student, Department of Civil Engineering, Chulalongkorn University, Bangkok, Thailand, piyawat_pwf@yahoo.com ABSTRACT: The December 26th, 2004 Indian Ocean tsunami caused damage to many buildings and killed many people in many Indian Ocean countries and the South of Thailand. Almost reinforced-concrete buildings in Thailand are the gravity load designed buildings and damaged ranging from no damage to collapse from that event. To understand behavior of a reinforced-concrete building, one-story building which is the former office of Thai Meteorological Department located in Phang-Nga province was tested under tsunami load pattern. In this research, the reinforced-concrete building model is constructed by using 3-dimensional non-linear static pushover analysis. In the building model, masonry infill walls are considered and idealized as the diagonal stud by using uniaxial non-linear springs. The results of the building model agree well with the test results on the displacement of each frame and damage on the masonry infill walls. The masonry infill wall in the middle frame can resist the lateral load of the top part load about 60%. This building with masonry infill walls can resist the lateral load 3 times higher than the resisting load of this building without masonry infill walls. To analyze the effect of masonry infill wall of reinforced-concrete building, the patterns of the wall are rearranged. The masonry infill walls with the appropriate arrangement can significantly improve the load resisting capacity of the building. Key Words: tsunami, tsunami load, reinforced concrete, building, nonlinear analysis INTRODUCTION The December 26th, 2004 Indian Ocean tsunami caused damage to several buildings in southern provinces of Thailand. Reinforced-concrete buildings in the area are mainly designed for gravity loads. One-story building which is the former office of Thai Meteorological Department located in Phang-Nga province was tested under tsunami load patterns. This research focuses on correlation analysis that experimental results to evaluate forces distribution in each member, the lateral resistance Proceedings of the International Symposium on Engineering Lessons Learned from the 2011 Great East Japan Earthquake, March 1-4, 2012, Tokyo, Japan 528