≥ Vx = 967050N,满足要求。
(3)、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{N2 , N3} = 967050N
柱左右两边边缘计算宽度 byo:
byo = b - (hc / 2 - 291) * Sb / Sa = 2128mm
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 = 750-800/2-433/2 = 133mm
λx = ax / ho = 133/(700-110) = 0.226
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 = 1*1.346*1.43*2128*590 = 2421906N
≥ Vy = 967050N,满足要求。
4、柱下局部受压承载力计算:
局部荷载设计值 F = 2901150N
混凝土局部受压面积 Al = bc * hc = 640000mm2
承台在柱下局部受压时的计算底面积按下列公式计算:
Ab = (bx + 2 * c) * (by + 2 * c)
c = Min{Cx, Cy, bx, by} = Min{850,760,800,800} = 760mm
Ab = (800+2*760)*(800+2*760) = 5382400mm2
βl = Sqr(Ab / Al) = Sqr(5382400/640000) = 2.9
ω * βl * fcc * Al = 1.0*2.9*0.85*14.33*640000 = 22609262N
≥ F = 2901150N,满足要求。
5、桩局部受压承载力计算:
局部荷载设计值 F =Nmax + γg * Qgk=967.1+1.35*46.9 = 1030.3kN
混凝土局部受压面积 Al = π * d ^ 2 / 4 = 196350mm2
承台在角桩局部受压时的计算底面积按下列公式计算:
Ab = (bx + 2 * c) * (by + 2 * c)
圆桩 bx = by = Sqr(Al) = 443mm
c = Min{Cx, Cy, bx, by} = Min{250,250,443,443} = 250mm
Ab = (443+2*250)*(443+2*250) = 889463mm2
βl = Sqr(Ab / Al) = Sqr(889463/196350) = 2.128
ω * βl * fcc * Al = 1.0*2.128*0.85*14.33*196350 = 5090815N
≥ F = 1030349N,满足要求。
7.5.1 柱下独立承台:CT-4
7.3 四桩承台简图
一、基本资料:
承台类型:四桩承台 圆桩直径 d = 500mm
桩列间距 Sa = 1500mm 桩行间距 Sb = 1500mm
桩中心至承台边缘距离 Sc = 500mm
承台根部高度 H=700mm 承台端部高度 h = 700mm
柱子高度 hc = 800mm(X 方向) 柱子宽度 bc = 800mm(Y 方向) 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(80):http://www.youerw.com/gongcheng/lunwen_1016.html