A.主梁寬-保護層+12d B.主梁寬-保護層+15d C.主梁寬-保護層+20d D.主梁寬-保護層
A.150 B.200 C.300 D.基礎(chǔ)厚
A.12d,≥0.6lab B.15d,≥0.6lab C.15d,≥1.1lab D.15d,≤0.6lab