Bending resistance of repaired column members and shear resistance of opening frames with repaired columns of conventional Japanese wooden houses

摘要

In many cases of reparing Japanese conventional wooden houses, decayed lower parts of columns should be replaced with new wood material. Bending resistance of columns repaired by four methods and shear resistance of opening frames with those repaired columns were investigated in this study. Bending tests of the repaired columns showed differences in initial bending stiffness and maximum bending moment among the combinations of repair methods and loading directions. Racking tests were conducted on door opening frames with conventional door head member or upper partial walls sheathed with 12mm thick plywood. The conventional frame specimens broke at door head-column joints with no obvious bending deformation of the columns, it resulted in little difference in load-shear deformation curves among the repair methods. The columns of plywood-sheathed specimens, on the other hand, were bent clearly after when the nails at the plywood to wood frame joints started to be pulled off. The load-shear deformation curves of the plywood-sheathed specimens did not vary regardless of the repair methods in small shear deformations, but affected by the repair methods as shear deformation increased.