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简答题有一栋二类框架建筑物,网格宽度W=5m,钢筋直径Φ=20mm,100m处发生首次云地闪。求LPZ1区的H1和安全距离ds/1。
  • H0=I/(2π·S)=150KA/(2×3.14×100)=0.239KA=293A/m
    H1=H0/10SF/20
    SF=20·log[8.5/W/(1+18×10-6/r21/2]
    SF=20·log[8.5/5/(1+18×10-6/10-41/2]
    SF=20·log[1.7/1.086]
    SF=20·log[1.5654]=20×0.1946=3.89≈3.9dB
    H1=239/10S3.9/20
    H1=239/1.57
    H1=152A/m
    ds/1=W·SF/10=5×3.9/10=1.95m
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