木ねじプローブの引き抜き抵抗を用いた木質部材の健全性診断: 曲げ強度に基づく既存木造建築物中の木質部材の健全性診断法

摘要

木造建築物を長期間使用するためには，保守点検において，使用 されている木質部材の健全性を調べ，劣化した部材を交換するなど の措置が必要である。既存木造建築物中の木質部材の健全性診断 は，従来は大工や木材に熟練した技術者により，主に視覚や打撃音 などを使って実施されてきた。%Inspection method of wood integrity using distribution of resistance to withdrawal of wood-screw type probes is proposed. The probes have a 5mm length thread and are screwed into wood. Withdrawal resistance of the probes in several depths is measured. Average withdrawal resistance provides integrity of wood. The distribution of withdrawal resistance of wood provides information of degradation in wood. Withdrawal resistance of wood-screw type probes and bending strengths of the specimens are compared. Based on allowable bending stress of wood, critical withdrawal resistance is proposed. Wood integrity is evaluated by comparing measured withdrawal resistance and critical withdrawal resistance.