Qk = (Fk + Gk) / n (基础规范 8.5.3-1)
Qk = (3979.4+219.1)/4 = 1049.6kN ≤ Ra = 1500kN
每根单桩所分配的承台自重和承台上土自重标准值 Qgk:
Qgk = Gk / n = 219.1/4 = 54.8kN
扣除承台和其上填土自重后的各桩桩顶相应于荷载效应基本组合时的竖向力设计值:
Ni = γz * (Qik - Qgk)
N = 1.35*(1049.6-54.8) = 1343.0kN
(2)、X 轴方向柱边的弯矩设计值:(绕 X 轴)
Mxct = 2 * N * (Sb - bc) / 2 = 2*1343*(1.5-0.8)/2 = 940.1kN•m
②号筋 Asy = 4783mm2 ζ = 0.084 ρ = 0.34%
2416@100 (As = 4825)
(3)、Y 轴方向柱边的弯矩设计值:(绕 Y 轴)
Myct = 2 * N * (Sa - hc) / 2 = 2*1343*(1.5-0.8)/2 = 940.1kN•m
①号筋 Asx = 4607mm2 ζ = 0.078 ρ = 0.31%
2416@100 (As = 4825)
2、承台受冲切承载力验算:
(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 = 5372190N
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 = 750-800/2-433/2 = 133mm
λox = aox / ho = 133/(700-110) = 0.226
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/(0.226+0.2) = 1.971
Y 方向上自柱边到最近桩边的水平距离:
aoy = 750 - 0.5bc - 0.5bp = 750-800/2-433/2 = 133mm
λoy = aoy / ho = 133/(700-110) = 0.226
Y 方向上冲切系数 βoy = 0.84 / (λoy + 0.2) (基础规范 8.5.17-4)
βoy = 0.84/(0.226+0.2) = 1.971
2 * [βox * (bc + aoy) + βoy * (hc + aox)] * βhp * ft * ho
= 2*[1.971*(800+133)+1.971*(800+133)]*1*1.43*590
= 6220721N ≥ Fl = 5372190N,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 = 1343047N
承台受角桩冲切的承载力按下列公式计算:
Nl ≤ [β1x * (c2 + a1y / 2) + β1y * (c1 + a1x / 2)] * βhp * ft * ho
(基础规范 8.5.17-5) 五层现浇钢筋混凝土框架结构商业中心建筑与结构设计和CAD图纸(82):http://www.youerw.com/gongcheng/lunwen_1016.html