安あん息そく角かく

noun

angle of repose

Technical term in civil engineering and geology for the steepest angle at which a pile of granular material remains stable.

• 砂すなの安あん息そく角かくは約やく35度どです。

  The angle of repose of sand is about 35 degrees.

• 安あん息そく角かくを超こえると斜しゃ面めんが崩くずれる。

  If the angle of repose is exceeded, the slope will collapse.