第一层 MBF= MBC+ MBA =57.29 kN·m +99.47 kN·m =156.8 kN·m MFB=(136.0+78.87)kN·m =143.2 kN·m MFJ=(136.0+78.87)kN·m =71.62 kN·m MJF= MJL+ MJI =42.29 kN·m +95.41 kN·m =137.7 kN·m