即可得主梁的弯矩包络图及剪力包络图,参见图纸。主梁正截面及斜截面承载力计算分别见表主梁正截面承载计算截面边跨跨中中间支座中间跨跨中M(kn·m)262.16-244.79138.40-42.02ɑs=M/(ɑ1fcbh02)0.02770.2040.01460.0044γs=0.5[1+(1-2ɑs)-0.5]0.9860.8850.9930.998As=M/fyγsh0(mm2)14411590755228选配钢筋2Φ22(直)+2Φ22(弯)4Φ22(直)+2Φ22(弯)2Φ222Φ18实配钢筋面积(mm2)15201777760509主梁斜截面承载力计算截面支座Ar支座B1支座BrV(kn)126.64-207.01176.250.25βcfcbh0=517.7kn0.7ftbh0=154.7knVA<154.7kn154.7kn<Vb1<517.7kn154.7kn<Vbr<517.7kn选用箍筋2Φ6@2002Φ6@2002Φ6@200Asv=nAsv1(mm2)56.656.656.6VCS=0.7ftbh0+1.25fyvAsvh0/s(kn)197.8197.8197.8Asb=V-VCS/0.8fy-54.3-选配弯筋-1Φ14-实际弯筋面积(mm2)-153.9-(5)主梁吊筋计算:由次梁传至主梁的全部集中力为:G+Q=59.41+86=145.41kn则AS=(G+Q)/2fysina=145.41×1000/(2×300×0.707)=342.8mm2选2Φ16(AS=402mm2);也可配置附加箍筋,配附加箍筋范围为:3b+2h1=3×200+2×200=1000mmASV=F1/fy=145.41×103/210=692.4mm2在次梁两侧各附加4道Φ8箍筋,则ASV=(4+4)×2×50.3=804.8mm2692.4mm2主梁配筋图见附图4。
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