A.min(la,主梁寬/2)+15d B.max(la,主梁寬/2) C.max(la,主梁寬/2)+15d D.max(la,主梁寬/2)+12d
A.15d B.≥0.6lab C.12d D.≥0.6lae
A.20mm B.50mm C.100mm D.s/2