Seismic risk analysis based on historical events reported in Sri Lanka

Seismicity of two main cities in Sri Lanka has been assessed based on historical events. Reported Modified Mercalli Intensity (MMI) data of selected historical events are compared with ground motion parameters modeled based on the stochastic approach with estimated seismological parameters. Site amplifications due to subsoil modifications are estimated performing equivalent linear analysis method using SHAKE2000. MMI data have been converted to peak ground velocities by available well established relationships and a good consistency has been noted between modeled and reported values. This facilitates to develop a design response spectrum for Colombo, the capital of the country, based on maximum credible earthquake