Blast mitigation by a full-scale concrete wall was evaluated. Cylindrically shaped TNT, weight of 80 kg was put on a wooden table, height of 0.6 or 0.8 m. Two kinds of concrete walls, height of 2.5 m from the ground level and width of 4 m were prepared. The distance from the TNT to the wall was 2 m. The blast pressure was measured at a total of 12 points, at four distances in three directions. The directions were 20°, 45°, and 90°, where 0° was defined as the vertical from the TNT to the wall plane. The scaled distance from the TNT was 2, 4, 8, and 16 m·kg−1/3. The peak pressure at direction of 20° and scaled distance of 4 m·kg−1/3 was remarkably mitigated. The peak pressure at direction of 20° and scaled distance of 8 and 16 m·kg−1/3 was almost the same as that without the wall. The peak pressure at direction of 45° and 90° was lower and higher, respectively, regardless of the distance. The impulse was mitigated at the point of direction of 45° and 4 m·kg−1/3. However, the obvious mitigation was not observed at all other points. Precise data, including typical blast wave profiles and the blast parameters, are presented in the text.
80 kgのTNTを地上高さ0.6-0.8 mの木製台上に置き、2種類の防爆壁（地上高さ2.5 m、幅4 m）から2 m離して点火し、3方向（20度, 45度, 90度）の各4点（換算距離2, 4, 8, 16 m・kg−1/3）で爆風圧計測を行った。ピーク圧力は、爆点から見て防爆壁の裏側に当たる20度方向の換算距離4 m・kg−1/3では、大幅に低減され、換算距離8, 16 m・kg−1/3では、防爆壁がない場合と変わらなかった。45度方向では、距離によらず全般に低め、90度方向では、全般に高めであった。インパルスに関しては、換算距離4 m・kg−1/3の45度方向の地点では、低減が確認されたが、それ以外の地点では、防爆壁がない場合とほとんど変わらなかった。
Blast wave, Mitigation, Concrete, Wall.