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锥型柱基DJp1计算书
项目名称_____________日 期_____________
设 计 者_____________校 对 者_____________
一、示意图
基础类型:锥型柱基 计算形式:验算截面尺寸
平面:
剖面:
二、基本参数
1.依据规范
《建筑地基基础设计规范》(GB 50007-2011)
《混凝土结构设计规范》(GB 50010-2010)
《简明高层钢筋混凝土结构设计手册(第四版)》
2.几何参数:
已知尺寸:
B1 = 2250 mm, A1 = 2250 mm
H1 = 200 mm, H2 = 450 mm
B = 500 mm, A = 500 mm
无偏心:
B2 = 2250 mm, A2 = 2250 mm
基础埋深d = 2.00 m
钢筋合力重心到板底距离as = 50 mm
3.荷载值:
(1)作用在基础顶部的标准值荷载
Fgk = 2200.00 kN Fqk = 10.00 kN
Mgxk = 1.30 kN·m Mqxk = 0.00 kN·m
Mgyk = 12.70 kN·m Mqyk = 0.00 kN·m
Vgxk = 6.90 kN Vqxk = 0.00 kN
Vgyk = -0.40 kN Vqyk = 0.00 kN
(2)作用在基础底部的弯矩标准值
Mxk = Mgxk+Mqxk = 1.30+0.00 = 1.30 kN·m
Myk = Mgyk+Mqyk = 12.70+0.00 = 12.70 kN·m
Vxk = Vgxk+Vqxk = 6.90+0.00 = 6.90 kN·m
Vyk = Vgyk+Vqyk = -0.40+0.00 = -0.40 kN·m
绕X轴弯矩: M0xk = Mxk-Vyk·(H1+H2) = 1.30--0.40×0.65 = 1.56 kN·m
绕Y轴弯矩: M0yk = Myk+Vxk·(H1+H2) = 12.70+6.90×0.65 = 17.18 kN·m
(3)作用在基础顶部的基本组合荷载
不变荷载分项系数rg = 1.25 活荷载分项系数rq = 1.40
F = rg·Fgk+rq·Fqk = 2764.00 kN
Mx = rg·Mgxk+rq·Mqxk = 1.63 kN·m
My = rg·Mgyk+rq·Mqyk = 15.88 kN·m
Vx = rg·Vgxk+rq·Vqxk = 8.63 kN
Vy = rg·Vgyk+rq·Vqyk = -0.50 kN
(4)作用在基础底部的弯矩设计值
绕X轴弯矩: M0x = Mx-Vy·(H1+H2) = 1.63--0.50×0.65 = 1.95 kN·m
绕Y轴弯矩: M0y = My+Vx·(H1+H2) = 15.88+8.63×0.65 = 21.48 kN·m
4.材料信息:
混凝土: C30 钢筋: HRB400(20MnSiV、20MnSiNb、20MnTi)
5.基础几何特性:
底面积:S = (A1+A2)(B1+B2) = 4.50×4.50 = 20.25 m2
绕X轴抵抗矩:Wx = (1/6)(B1+B2)(A1+A2)2 = (1/6)×4.50×4.502 = 15.19 m3
绕Y轴抵抗矩:Wy = (1/6)(A1+A2)(B1+B2)2 = (1/6)×4.50×4.502 = 15.19 m3
三、计算过程
1.修正地基承载力
修正后的地基承载力特征值 fa = 150.00 kPa
2.轴心荷载作用下地基承载力验算
计算公式:
按《建筑地基基础设计规范》(GB 50007-2011)下列公式验算:
pk = (Fk+Gk)/A (5.2.2-1)
Fk = Fgk+Fqk = 2200.00+10.00 = 2210.00 kN
Gk = 20S·d = 20×20.25×2.00 = 810.00 kN
pk = (Fk+Gk)/S = (2210.00+810.00)/20.25 = 149.14 kPa ≤ fa,满足要求。
3.偏心荷载作用下地基承载力验算
计算公式:
按《建筑地基基础设计规范》(GB 50007-2011)下列公式验算:
当e≤b/6时,pkmax = (Fk+Gk)/A+Mk/W (5.2.2-2)
pkmin = (Fk+Gk)/A-Mk/W (5.2.2-3)
当e>b/6时,pkmax = 2(Fk+Gk)/3la (5.2.2-4)
X、Y方向同时受弯。
偏心距exk = M0yk/(Fk+Gk) = 17.18/(2210.00+810.00) = 0.01 m
e = exk = 0.01 m ≤ (B1+B2)/6 = 4.50/6 = 0.75 m
pkmaxX = (Fk+Gk)/S+M0yk/Wy
= (2210.00+810.00)/20.25+17.18/15.19 = 150.27 kPa
偏心距eyk = M0xk/(Fk+Gk) = 1.56/(2210.00+810.00) = 0.00 m
e = eyk = 0.00 m ≤ (A1+A2)/6 = 4.50/6 = 0.75 m
pkmaxY = (Fk+Gk)/S+M0xk/Wx
= (2210.00+810.00)/20.25+1.56/15.19 = 149.24 kPa
pkmax = pkmaxX+pkmaxY-(Fk+Gk)/S = 150.27+149.24-149.14 = 150.37 kPa
≤ 1.2×fa = 1.2×150.00 = 180.00 kPa,满足要求。
4.基础抗冲切验算
计算公式:
按《建筑地基基础设计规范》(GB 50007-2011)下列公式验算:
Fl ≤ 0.7·βhp·ft·am·h0 (8.2.7-1)
Fl = pj·Al (8.2.7-3)
am = (at+ab)/2 (8.2.7-2)
pjmax,x = F/S+M0y/Wy = 2764.00/20.25+21.48/15.19 = 137.91 kPa
pjmin,x = F/S-M0y/Wy = 2764.00/20.25-21.48/15.19 = 135.08 kPa
pjmax,y = F/S+M0x/Wx = 2764.00/20.25+1.95/15.19 = 136.62 kPa
pjmin,y = F/S-M0x/Wx = 2764.00/20.25-1.95/15.19 = 136.37 kPa
pj = pjmax,x+pjmax,y-F/S = 137.91+136.62-136.49 = 138.04 kPa
(1)柱对基础的冲切验算:
H0 = H1+H2-as = 0.20+0.45-0.05 = 0.60 m
X方向:
Alx = 1/4·(A+2H0+A1+A2)(B1+B2-B-2H0)
= (1/4)×(0.50+2×0.60+4.50)(4.50-0.50-2×0.60)
= 4.34 m2
Flx = pj·Alx = 138.04×4.34 = 599.08 kN
ab = min{A+2H0, A1+A2} = min{0.50+2×0.60, 4.50} = 1.70 m
amx = (at+ab)/2 = (A+ab)/2 = (0.50+1.70)/2 = 1.10 m
Flx ≤ 0.7·βhp·ft·amx·H0 = 0.7×1.00×1430.00×1.100×0.600
= 660.66 kN,满足要求。
Y方向:
Aly = 1/4·(B+2H0+B1+B2)(A1+A2-A-2H0)
= (1/4)×(0.50+2×0.60+4.50)(4.50-0.50-2×0.60)
= 4.34 m2
Fly = pj·Aly = 138.04×4.34 = 599.08 kN
ab = min{B+2H0, B1+B2} = min{0.50+2×0.60, 4.50} = 1.70 m
amy = (at+ab)/2 = (B+ab)/2 = (0.50+1.70)/2 = 1.10 m
Fly ≤ 0.7·βhp·ft·amy·H0 = 0.7×1.00×1430.00×1.100×0.600
= 660.66 kN,满足要求。
5.基础受压验算
计算公式:《混凝土结构设计规范》(GB 50010-2010)
Fl ≤ 1.35·βc·βl·fc·Aln (7.8.1-1)
局部荷载设计值:Fl = 2764.00 kN
混凝土局部受压面积:Aln = Al = B×A = 0.50×0.50 = 0.25 m2
混凝土受压时计算底面积:Ab = min{B+2A, B1+B2}×min{3A, A1+A2} = 2.25 m2
混凝土受压时强度提高系数:βl = sq.(Ab/Al) = sq.(2.25/0.25) = 3.00
1.35βc·βl·fc·Aln
= 1.35×1.00×3.00×14300.00×0.25
= 14478.75 kN ≥ Fl = 2764.00 kN,满足要求。
6.基础受弯计算
计算公式:
按《简明高层钢筋混凝土结构设计手册(第四版)》中下列公式验算:
MⅠ=β/48·(L-a)2(2B+b)(pjmax+pjnx) (11.4-7)
MⅡ=β/48·(B-b)2(2L+a)(pjmax+pjny) (11.4-8)
(1)柱根部受弯计算:
G = 1.35Gk = 1.35×810.00 = 1093.50kN
Ⅰ-Ⅰ截面处弯矩设计值:
pjnx = pjmin,x+(pjmax,x-pjmin,x)(B1+B2+B)/2/(B1+B2)
= 135.08+(137.91-135.08)×(4.50+0.50)/2/4.50
= 136.65 kPa
MⅠ = β/48·(B1+B2-B)2[2(A1+A2)+A](pjmax,x+pjnx)
= 1.0000/48×(4.50-0.50)2×(2×4.50+0.50)×(137.91+136.65)
= 869.44 kN·m
Ⅱ-Ⅱ截面处弯矩设计值:
pjny = pjmin,y+(pjmax,y-pjmin,y)(A1+A2+A)/2/(A1+A2)
= 136.37+(136.62-136.37)×(4.50+0.50)/2/4.50
= 136.51 kPa
MⅡ = β/48·(A1+A2-A)2[2(B1+B2)+B](pjmax,y+pjny)
= 1.0000/48×(4.50-0.50)2×(2×4.50+0.50)×(136.62+136.51)
= 864.91 kN·m
Ⅰ-Ⅰ截面受弯计算:
相对受压区高度: ζ= 0.038263 配筋率: ρ= 0.001520
计算面积:911.93 mm2/m
Ⅱ-Ⅱ截面受弯计算:
相对受压区高度: ζ= 0.038060 配筋率: ρ= 0.001512
计算面积:907.09 mm2/m
四、计算结果
1.X方向弯矩验算结果:
计算面积:911.93 mm2/m
采用方案:f12@110
实配面积:1028.16 mm2/m
2.Y方向弯矩验算结果:
计算面积:907.09 mm2/m
采用方案:f12@110
实配面积:1028.16 mm2/m
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