Abstract
Various laboratory tests have been performed to investigate the strength, bearing capacity and deformation characteristics of fly ash and the application of the improvement of roadbed using fly ash for railway track causing mud-pumping. In addition, numerical calculations used the results of tests were performed to compare the effect of the improvement of roadbed using fly ash with that of the sand blanketing measures. It was found that fly ash has enough durability against repeated load and seepage water and that the calculated coefficients of subgrade reaction increase as the elapsed day. The improvement of roadbed using fly ash is useful for taking preventive measures against mud-pumping.
