Repairing and Recovering Structural Performance of Earthen Walls Used in Japanese Dozo-Style Structures After Seismic Damage

Several traditional building group districts exist in Japan as a system for preserving the remaining historical villages and townscapes of the country, along with their surrounding environment. In the northern Kanto region of Japan, there remain examples of many dozo-style structures called “Dozo-dukuri,” forming a distinctive historical townscape. In the 2011 Tohoku Region Pacific Offshore Earthquake, the traditional townscapes and dozo-style structures of the Kanto region were seriously damaged. When restoring the walls of damaged dozo-style structures to a sound condition, demolishing and reconstructing all the mud requires considerable labor; moreover, few modern artisans can construct mud walls. However, if there was a method that could recover the structural performance of the walls immediately via partial repair, the restoration of the walls could again become economical. Therefore, in this study, we first surveyed the specifications of mud walls in the northern Kanto region. Then, we performed horizontal loading tests on full-scale walls produced according to the survey results to determine the structural performance of walls under a horizontal force, e.g., an earthquake. Further, a test specimen damaged by a horizontal force was repaired, and a horizontal loading test was performed again. The results elucidated the structural performance recoverability obtained by the proposed repair method.