In this paper, the authors focus on the repair design of thickness-reduced steel members by patch plates with high-strength bolts. In the previous papers, it has been reported that the axial-force sharing in thickness-reduce steel plate does not correspond to that calculated by the composite theory of the thickness-reduced plate and the patch plates. However, so far, the dead load in steel members and slip load of patch plates are not considered in the previous studies. In this research, the effect of dead load and slippage of patch plates are considered to the patch plate repair method for the thickness-reduced plate. Finally, the authors discussed how to design the patch plates to enable or disable the thickness-reduce plates.
