木造住宅土塗壁の実大耐震性能実験

Abstract

木造住宅で一般に用いられる竹小舞下地土塗り壁のせん断繰返し載荷実験を行い, 耐力と変形性能および壁倍率などの耐震性能評価を行った。最大耐力時の変形は, 1/60-1/10radと大きい。壁倍率は, 壁土の付いた試験体では全て1.0以上であり, 現行の規定である0.5を上回っている。ホールダウン金物などにより, 接合部の破壊を防げば, 耐力壁としての機能を十分果たすと言える。壁土による耐力増加は, 筋かいの有無によらずほぼ一定であり, 筋かいによる耐力増加も, 壁土の有無に関わらずほぼ等しい。

Mud-plastered walls usually used in wood houses made by carpenters and plasterers in Kyoto were tested by repeated shear force loading in order to evaluate their seismic resistance capacities such as the relation between bearing capacity and deformability and the coefficient of effective wall length. The deformation angles at maximum load are greater than 1/60rad. The average coefficients of effective wall-length are greater than 0.5 which is the standard value determined in the Enforcement Ordinance of The Building Standard Law in Japan. It seems that if the joints of the framework are fixed by some metals such as holddown metals to avoid the separation of the framework, mud-plastered walls can function as the bearing wall. The average increases in bearing force by wall-mud are nearly same in both cases of with and without a brace, and so those by the brace are in both cases of with and without wall-mud.