In this study, I presented the experimental results of four 1P mud walls, which two damage levels of the walls, the experienced maximum deformation angle and the accumulated one, are known. The strength characteristics after the restoration were examined, based on the results of the cyclic loading test of these walls. In the restorations, I took care to ensure that there was no gap between the practice and the research. The experimental formulas for the stiffness reduction factor and the strength reduction factor after restoration compared to before restoration were shown by comparing the envelopes of the restoring force characteristics.
