(1)、柱对承台的冲切验算:
扣除承台及其上填土自重,作用在冲切破坏锥体上的冲切力设计值:
Fl = 2984445N
柱对承台的冲切,可按下列公式计算:
Fl ≤ 2 * [βox * (bc + aoy) + βoy * (hc + aox)] * βhp * ft * ho
(基础规范 8.5.17-1)
X 方向上自柱边到最近桩边的水平距离:
aox = 750 - 0.5hc - 0.5bp = 750-650/2-433/2 = 208mm
λox = aox / ho = 208/(950-110) = 0.248
X 方向上冲切系数 βox = 0.84 / (λox + 0.2) (基础规范 8.5.17-3)
βox = 0.84/(0.248+0.2) = 1.874
aoy = Min{Sb - 0.5bc, Ho} = Min{225,840} = 225mm
2 * βox * (bc + aoy) * βhp * ft * ho
= 2*1.874*(550+225)*0.988*1.43*840
= 3452726N ≥ Fl = 2984445N,满足要求。
(2)、角桩对承台的冲切验算:
扣除承台和其上填土自重后的角桩桩顶相应于荷载效应基本组合时的竖向力设计值:
Nl = Nmax = 1492222N
承台受角桩冲切的承载力可由基础规范 8.5.17-1 式推导出按下列公式:
Nl ≤ β1x * (bp + a1y) * βhp * ft * ho
X 方向上自桩内边缘到最近柱边的水平距离:
a1x = 750 - 0.5hc - 0.5bp = 750-650/2-433/2 = 208mm
λ1x = a1x / ho = 208/(950-110) = 0.248
X 方向上冲切系数 β1x = 0.84 / (λ1x + 0.2) (基础规范 8.5.17-3)
β1x = 0.84/(0.248+0.2) = 1.874
a1y = Min{Sb - 0.5bp, ho} = Min{283,840} = 283mm
β1x * (bp + a1y) * βhp * ft * ho
= 1.874*(433+283)*0.988*1.43*840
= 1596064N ≥ Nl = 1492222N,满足要求。
3、承台斜截面受剪承载力计算:
(1)、Y方向斜截面受剪承载力计算:
扣除承台及其上填土自重后 Y 方向斜截面的最大剪力设计值:
Vy = Max{N1, N2} = 1492222N
承台斜截面受剪承载力按下列公式计算:
Vy ≤ βhs * βx * ft * byo * ho (基础规范 8.5.18-1)
Y 方向上自桩内边缘到最近柱边的水平距离:
ax = 750 - 0.5hc - 0.5bp = 750-650/2-433/2 = 208mm
λx = ax / ho = 208/(950-110) = 0.248
当 λx < 0.3 时,取 λx = 0.3
βx = 1.75 / (λx + 1.0) = 1.75/(0.3+1.0) = 1.346
βhs * βx * ft * byo * ho = 0.99*1.346*1.43*1000*840 = 1600626N
≥ Vy = 1492222N,满足要求。 中学五层教学楼建筑与结构设计+CAD图纸(75):http://www.youerw.com/gongcheng/lunwen_554.html