The authors proposed a technique for improving the fatigue strength of the weld root of sole plate by filling the resin. In this research, fatigue tests were carried out on sole plate specimens with and without filling the resin between sole plate and base plate. As the results of the fatigue tests, the fatigue strength of weld root was enhanced by filling the resin in the root gap. Furthermore, it was shown that the fatigue life can be estimated by the fatigue strength evaluation method using deformation of the weld root.
