Development of national guidelines for seismic analysis and design of (engineered) buildings in Sri Lanka

Abstract

Sri Lanka was believed to have no seismic threat compared to other natural disasters such as landslides, floods, droughts, etc. However, it has now been realized that Sri Lanka can no longer be considered as isolated from seismic threat following recent past events occurred in and around island. The only available document for the purpose of seismic design of buildings in Sri Lanka “Earthquake resistant detailing for buildings in Sri Lanka” published by the Society of Structural Engineers, Sri Lanka. The present study is therefore aimed to provide advice on the seismic design in Sri Lanka and provide guidance on suitable analyse seismic consideration is explicitly warranted for a structure. The proposed guidelines in this study are based on Euro Code 8 (EN 1998 Code 8 was selected for this purpose because it allows national choices in defining seismic characteristics such as peak ground accelerations, response spectra etc. in the seismic design procedure. It also allows national choices in selecting analysis and design resist seismic events. Therefore, this study mainly focuses on these national choices and suitable values are proposed and discussed depending on the available limited seismic data in Sri Lanka. Whenever there is no enough data, such as IS 1893-1: 2002 and AS 1170.4: 2007. Finally, two case studies are carried out in order to illustrate how the developed guidelines are used in the seismic design procedure of buildings specifically in Sri Lanka. The two buildings selected for this purpose represent buildings with high consequences of failure during an earthquake so that it clearly shows the significance of seismic consideration in the design procedure of buildings.