1.解 : 查表:
γd = 1.2 , f c=10N/mm2,γ0= 1.0, ψ =1.0, γG= 1.05, γQ =1.20
(1) 内力计算 M= γ 0ψ(q+g)l0×l0/8
(3) 配筋计算 取 as =35mm, 则 h0 =h-as= 500 -35 =465mm
该梁的纵向受拉钢筋面积 As=882mm2。
2. 解:
(1) 确定受压区计算高度 x
h 0 = h-as =550-(25+20/2) = 515 mm
X=fyAs/fcb= (310×941)/(10 ×250)=116.7mm<ξbh0=
0.544×515=280.2mm 不会发生超筋破坏。
(2)计算正截面受弯承载力 Mu
Mu = fc x ( h 0 -0.5 x)
=10 ×250×116.7×(515-0.5×116.7)=133.2kN.m