Free standing steel structures, whose column bases are not fixed to a foundation, contribute to decrease damage to the structures under large earthquakes. However, the friction coefficient of normal steel column bases is 0.8 and too high to the strengths of normal steel structures. In this study, a steel column base lubricated by graphite well known as a lubricant and a cast iron column base containing much more graphite than steel are proposed to realize the low friction column base. Shaking table tests are conducted to investigate the friction characteristics. The tests show that the friction coefficient of the cast iron column base is 0.25 and that of the graphite lubricated steel column base is 0.20. Dynamic response analyses representing these friction characteristics show reasonable correlations with the test results.
