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屋盖、楼盖设计|屋盖、楼盖设计图

 

  一 屋盖、楼盖设计

  (一)屋盖

  1.设计资料

  1)屋面做法:钢筋混凝土现浇板,20mm石灰砂浆抹底,20mm水泥砂浆找平,40~120厚(1%找坡)膨胀珍珠岩保温层,四层作法防水层(一毡二油上铺小石子)

  2)屋面荷载:均布活荷载标准值2kN/m2(上人屋面),雪荷载标准值为0.65kN/m2

  3)材料:混凝土强度等级为C30;梁内受力纵筋为HRB335,其余为HPB235钢筋

  2.屋盖的结构平面布置图

  3.板的设计(弹性理论)

  1)荷载计算

  由于屋面均布活荷载标准值大于屋面雪荷载标准值,故取前者进行计算

  恒荷载标准值:

  20厚水泥混凝土找平0.02×20=0.46kN/m2

  40~120厚(1%找坡)膨胀珍珠岩(0.08+0.16)÷2×7=0.546kN/m2

  四层作法防水层 0.36kN/m2

  100mm厚钢筋混凝土楼板 0.1×25=2.56kN/m2

  20mm厚石灰砂浆抹底 0.02×17=0.34kN/m2

  小计 4.08 kN/m2

  荷载设计值

  g=1.2×4.08=4.90kN/m2 ,q=1.4×2.0=2.8kN/m2

  q/2=1.4kN/m2,g+q/2=6.3kN/m2,g+q=7.7kN/m2

  2)弯矩计算

  计算过程见下页表中

  3)截面设计

  截面有效高度:假定选用Φ8钢筋,则l01方向跨中截面的h01=80mm;l02方向跨中截面的h02=70mm;支座截面h0=80mm。

  最小配筋率:因为,故取ρsmin=0.27%,则Asmin=0.27%×1000×100=270mm2

  截面设计时取用的弯矩设计值:中间跨的跨中截面及中间支座截面减小20%;边跨跨中截面及楼板边缘算起的第二个支座截面处,当lb/l0<1.5时减小20%,当lb/l0=1.5~2.0时减小10%;楼板的角区格不折减。

  弯矩值计算表

  ABCDEFGH

  l01 (m)3.93.93.03.03.33.43.93.9

  l02 (m)7.27.27.83.93.93.97.27.2

  l01/l020.540.540.380.770.850.870.540.54

  m1(0.0388+0.2×0.0052) ×6.3×3.92+ (0.0232+0.2×0.0810) ×1.4×3.92=4.58(0.0388+0.2×0.0052) ×6.3×3.92+ (0.0535+0.2×0.0099) ×1.4×3.92=5.00(0.0400+0.2×0.0038) ×6.3×3.92+ (0.0965+0.2×0.0174) ×1.4×3.92=3.57(0.0285+0.2×0.0136) ×6.3×3.92+ (0.0376+0.2×0.0196) ×1.4×3.92=2.14(0.0246+0.2×0.0156) ×6.3×3.92+ (0.0225+0.2×0.0255) ×1.4×3.92=2.32(0.0235+0.2×0.0159) ×6.3×3.92+ (0.0329+0.2×0.0124) ×1.4×3.92=2.52(0.0388+0.2×0.0052) ×6.3×3.92+ (0.0907+0.2×0.0203) ×1.4×3.92=5.84(0.0388+0.2×0.0052) ×6.3×3.92+ (0.0121+0.2×0.0504) ×1.4×3.92=4.29

  m2(0.0052+0.2×0.0388) ×6.3×3.92+ (0.0810+0.2×0.0232) ×1.4×3.92=3.07(0.0052+0.2×0.0388) ×6.3×3.92+ (0.0099+0.2×0.0535) ×1.4×3.92=1.68(0.0038+0.2×0.0400) ×6.3×3.92+ (0.0174+0.2×0.0965) ×1.4×3.92=1.13(0.0136+0.2×0.0285) ×6.3×3.92+ (0.0196+0.2×0.0376) ×1.4×3.92=1.44(0.0156+0.2×0.0246) ×6.3×3.92+ (0.0255+0.2×0.0225) ×1.4×3.92=1.87(0.0159+0.2×0.0235) ×6.3×3.92+ (0.0124+0.2×0.0329) ×1.4×3.92=1.81(0.0052+0.2×0.0388) ×6.3×3.92+ (0.0203+0.2×0.0907) ×1.4×3.92=2.06(0.0052+0.2×0.0388) ×6.3×3.92+ (0.504+0.2×0.0121) ×1.4×3.92=2.37

  m’1-0.0817×7.7×3.92= -9.57-0.0817×7.7×3.92= -9.57-0.0829×7.7×3.02= -5.74-0.0686×7.7×3.02= -4.75-0.0626×7.7×3.32= -5.25-0.0611×7.7×3.42= -5.44-0.0817×7.7×3.92= -9.57-0.0817×7.7×3.92= -9.57

  m’2-0.0571×7.7×3.92= -6.69-0.0571×7.7×3.92= -6.69-0.0570×7.7×3.02= -3.95-0.0563×7.7×3.02= -3.90-0.0551×7.7×3.32= -4.62-0.0547×7.7×3.42= -4.87-0.0571×7.7×3.92= -6.69-0.0571×7.7×3.92= -6.69

  为了便于计算,近似取γ=0.95,

  计算过程见下表

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