在长江干流航道实行分边通航制原因主要是()
A、水位下落,透航道变窄
B、枯水期,船舶在急弯段航法的需要
C、为保证船舶航行和会让安全
D、A+B+C才对
参考答案:C
某钢筋混凝土T形截而独立简支梁,设计使用年限为50年,结构安全等级为二级,混凝土强度等级为C25,荷载简图及截面尺寸如图所示。梁上有均布静荷载gk,均布活荷载qk,集中静荷载Gk,集中活荷载Pk;各种荷载均为标准值。活荷载的组合值系数为0.7。
已知:as=65mm,fyv=270N/mm2,ft=1.27N/mm2,gk=qk=4kN/m,Gk=Pk=40kN,箍筋采用HPB300级钢筋。试问,当采用双肢箍且间距为200mm时,该梁斜截面抗剪所需的箍筋的单肢截面面积的计算值(mm2),应与下列何项数值最为接近()
A.42
B.54
C.65
D.108
A.The refrigerator was repaired by an old man.
B.The refrigerator will be fixed if it is under warranty.
C.Mrs. Green had her refrigerator fixed for nothing.
D.Mrs. Green would have had the refrigerator repaired if she had warranty.