三樁樁基承臺計算

1、樁樁基承臺計算項目名稱 日 期 設(shè) 計 者 校 對 者 一、設(shè)計依據(jù)建筑地基基礎(chǔ)設(shè)計規(guī)范 (GB50007-2011 ) 混凝土結(jié)構(gòu)設(shè)計規(guī)范 (GB50010- 2010) 建筑樁基技術(shù)規(guī)范 (JGJ 94 2008) 二、示意圖三、計算信息承臺類型 : 三樁承臺 計算類型 : 驗算截面尺寸構(gòu)件編號 : CT21. 幾何參數(shù)矩形柱寬 bc=500mm 矩形柱高 hc=550mm圓樁直徑 d=600mm承臺根部高度 H=1250mmx 方向樁中心距 A=1800mmy 方向樁中心距 B=1800mm承臺邊緣至邊樁中心距C=600mm材料信息柱混凝土強度等級 :C352ft_c=1.57N/mm

2、2,2fc_c=16.7N/mm承臺混凝土強度等級 :C30ft_b=1.43N/mm 2,fc_b=14.3N/mm2樁混凝土強度等級 :C30ft_p=1.43N/mm 2,2fc_p=14.3N/mm2承臺鋼筋級別 : HRB400 fy=360N/mm 23. 計算信息結(jié)構(gòu)重要性系數(shù)：丫 0=1.0縱筋合力點至近邊距離 : as=155mm4. 作用在承臺頂部荷載標(biāo)準(zhǔn)值Fgk=4418.000kN Fqk=0.000kNMgxk=81.000kN*m Mqxk=0.000kN*mMgyk=6.000kN*m Mqyk=0.000kN*mVgxk=5.000kNVqxk=0.000kNV

3、gyk=57.000kNVqyk=0.000kN永久荷載分項系數(shù) rg=1.20可變荷載分項系數(shù) rq=1.40Fk=Fgk+Fqk=4418.000+(0.000)=4418.000kN Mxk=Mgxk+Fgk*(B2-B1)/2+Mqxk+Fqk*(B2-B1)/2=81.000+4418.000*(0.000-0.000)/2+(0.000)+0.000*(0.000-0.000)/2 =81.000kN*mMyk=Mgyk+Fgk*(A2-A1)/2+Mqyk+Fqk*(A2-A1)/2=6.000+4418.000*(0.000-0.000)/2+(0.000)+0.000*(0.

4、000-0.000)/2 =6.000kN*mVxk=Vgxk+Vqxk=5.000+(0.000)=5.000kNVyk=Vgyk+Vqyk=57.000+(0.000)=57.000kNF1=rg*Fgk+rq*Fqk=1.20*(4418.000)+1.40*(0.000)=5301.600kNMx1=rg*(Mgxk+Fgk*(B2-B1)/2)+rq*(Mqxk+Fqk*(B2-B1)/2)=1.20*(81.000+4418.000*(0.000-0.000)/2)+1.40*(0.000+0.000*(0.000-0.000)/2)=97.200kN*mMy1=rg*(Mgyk+

5、Fgk*(A2-A1)/2)+rq*(Mqyk+Fqk*(A2-A1)/2)=1.20*(6.000+4418.000*(0.000-0.000)/2)+1.40*(0.000+0.000*(0.000-0.000)/2)=7.200kN*mVx1=rg*Vgxk+rq*Vqxk=1.20*(5.000)+1.40*(0.000)=6.000kNVy1=rg*Vgyk+rq*Vqyk=1.20*(57.000)+1.40*(0.000)=68.400kNF2=1.35*Fk=1.35*4418.000=5964.300kNMx2=1.35*Mxk=1.35*81.000=109.350kN*m

6、My2=1.35*Myk=1.35*6.000=8.100kN*mVx2=1.35*Vxk=1.35*5.000=6.750kNVy2=1.35*Vyk=1.35*57.000=76.950kNF=max(|F1|,|F2|)=max(|5301.600|,|5964.300|)=5964.300kNMx=max(|Mx1|,|Mx2|)=max(|97.200|,|109.350|)=109.350kN*mMy=max(|My1|,|My2|)=max(|7.200|,|8.100|)=8.100kN*mVx=max(|Vx1|,|Vx2|)=max(|6.000|,|6.750|)=6.7

7、50kNVy=max(|Vy1|,|Vy2|)=max(|68.400|,|76.950|)=76.950kN四、計算參數(shù)1. 承臺總長 Bx=C+A+C=0.600+1.800+0.600=3.000m2. 承臺總寬 By=C+B+C=0.600+1.800+0.600=3.000m3. 承臺根部截面有效高度 ho=H-as=1.250-0.155=1.095m4. 圓樁換算截面寬度 bp=0.8*d=0.8*0.600=0.480m五、內(nèi)力計算1. 各樁編號及定位座標(biāo)如上圖所示 :0 仁arccos(0.5*A/B)=1.0470 2=2*arcsin(0.5*A/B)=1.0471 號樁

8、 (x1=-A/2=-0.900m, y1=-B*cos(0.5* 0 2)/3= -0.520m)2 號樁 (x2=A/2=0.900m, y2=- B*cos(0.5* 0 2)/3= -0.520m)3號樁 (x3=0, y3=B*cos(0.5*0 2)*2/3=1.039m)刀Xi=Xi2*2=1.620m22刀y i =yi *2+y3 =1.620mNI=F/n-Mx*y J 刀y i2+My*x/ 刀xi2+Vx*H*x/ 刀xi2-Vy*H*y 1/ 刀y i2N1=5964.300/3-109.350*(-0.520)/1.620+8.100*(-0.900)/1.620

9、+6.750*1.250*(-0.900)/1.620-76.950*1.250*(-0.520)/1.620 =1983.134kNN2=5964.300/3-109.350*(-0.520)/1.620+8.100*0.900/1.620+6.750*1.250*0.900/1.620-76.950*1.250*(-0.520)/1.620=2001.509kNN3=5964.300/3-109.350*1.039/1.620+8.100*0.000/1.620 +6.750*1.250*0.000/1.620-76.950*1.250*1.039/1.620 =1979.656kN六、柱

10、對承臺的沖切驗算1. 刀 Ni=0=0.000kNho1=h-as=1.250-0.155=1.095m2. a ox二A/2-bc/2-bp/2=1.800/2-1/2*0.500-1/2*0.480=0.410ma oy12二y2-hc/2-bp/2=0.520-0.550/2-0.480/2=0.005ma oy3=y3-hc/2-bp/2=1.039-0.550/2-0.480/2=0.524m3. 入 ox= a ox/ho1=0.410/1.095=0.374入 oy12=a oy12/ ho仁0.219/1.095=0.200入 oy3= a oy3/ho1=0.524/1.09

11、5=0.4794. B ox=0.84/(入 ox+0.2)=0.84/(0.374+0.2)=1.462B oy12=0.84/(入 oy12+0.2)=0.84/(0.200+0.2)=2.100B oy3=0.84/(入 oy3+0.2)=0.84/(0.479+0.2)=1.2386. 計算沖切臨界截面周長AD=0.5*A+C/ta n(0.5* 0 1)=0.5*1.800+0.600/ta n(0.5*1.047)=1.939mCD二AD*ta n(0 1)=1.939*ta n(1.047)=3.359mAE=C/tan(0.5* 0 1)=0.600/tan(0.5*1.047

12、)=1.039m6.1 計算 Umx1Umx仁bca ox=0.500+0.410=0.910m6.2 計算 Umx2Umx2=2*AD*(CD-C-|y1|-|y3|+0.5*bp)/CD =2*1.939*(3.359-0.600-|-0.520|-|1.039|+0.5*0.480)/3.359 =1.663m因 Umx2>Umx取 Umx2=Umx1=0.910mUmy=hca oy12+a oy3=0.550+0.219+0.524=1.293m因 Umy>(C*tan( 0 1)/tan(0.5*0 1) -C-0.5*bpUmy=(C*tan( 0 1)/tan(0.

13、5*0 1) -C-0.5*bp=(0.600*tan(1.047)/tan(0.5*1.047)-0.600-0.5*0.480 =0.960m7. 計算沖切抗力因 H=1.250m 所以 B hp=0.963Y o*Fl= Y o*(F -刀 Ni)=1.0*(5964.300 -0.000)=5964.30kN B ox*2*Umy+B oy12*Umx1+B oy3*Umx2* B hp*ft_b*ho=1.462*2*0.960+2.100*0.910+1.238*0.910*0.963*1.43*1.095*1000 =8808.946kNY o*FI柱對承臺的沖切滿足規(guī)范要求七、

14、角樁對承臺的沖切驗算1. NI=max(N1,N2)=2001.509kNho1=h-as=1.250-0.155=1.095m2. a11=(A-bc-bp)/2=(1.800-0.500-0.480)/2=0.410m a12=(y3-(hc d)*0.5)*cos(0.5*0 2)=(1.039 -(0.550-0.480)*0.5)*cos(0.5*1.047)=0.454m入 11二a11/ho=0.410/1.095=0.374B 11=0.56/(入 11+0.2)=0.56/(0.374+0.2)=0.975C1=(C/tan(0.5* 0 1)+0.5*bp=(C/tan(0

15、.5*1.047)+0.5*0.480=1.279m入 12=a12/ho=0.454/1.095=0.415B 12=0.56/(入 12+0.2)=0.56/(0.415+0.2)=0.911C2=(CD-C-|y1|-y3+ 0.5d)*cos(0.5*0 2)=(3.359 -0.600-|-0.520|-1.039+0.5*1.047)*cos(0.5*0.480)=1.247m3. 因 h=1.250m 所以 B hp=0.963Y o*NI=1.0*2001.509=2001.509kNB 11*(2*C1+a11)*(tan(0.5*0 1)* B hp*ft_b*ho=0.9

16、75*(2*1279.230+410.000)*(tan(0.5*1.047)*0.963*1.43*1095.000=2518.101kN>Y o*Nl=2001.509kN 底部角樁對承臺的沖切滿足規(guī)范要求Y o*N3=1.0*1979.656=1979.656kNB 12*(2*C2+a12)*(tan(0.5*0 2)* B hp*ft_b*ho=0.911*(2*1247.077+453.997)*(tan(0.5*1.047)*0.963*1.43*1095.000* 1000=2337.378kNY o*N3=1979.656kN頂部角樁對承臺的沖切滿足規(guī)范要求八、承臺斜截

17、面受剪驗算1. 計算承臺計算截面處的計算寬度2. 計算剪切系數(shù)因 0.800ho=1.095m<2.000m, p hs=(0.800/1.095)1/4=0.925ay=|y3|-0.5*hc-0.5*bp=|1.039|-0.5*0.550-0.5*0.480=0.524入 y=ay/ho=0.524/1.095=0.479p y=1.75/(入 y+1.0)=1.75/(0.479+1.0)=1.18322bxo=A*(2/3+hc/2/sqrt(B 2-(A/2) 2)+2*C =1.800*(2/3+0.550/2/sqrt(1.8002-(1.800/2) 2)+2*0.60

18、0=2.718mY o*Vy=1.0*3984.644=3984.644kNp hs*p y*ft_b*bxo*ho=0.925*1.183*1.43*2717.543*1095.000=4655.743kN>Y o*Vy=3984.644kN承臺斜截面受剪滿足規(guī)范要求九、承臺受彎計算1. 確定單樁最大豎向力Nmax=max(N1, N2, N3)=2001.509kNM=Nmax*(A-(sqrt(3)/4)*bc)/3=2001.509*(1.800-(sqrt(3)/4)*0.500)/3=1056.459kN*m3. 計算系數(shù)C30 混凝土 a 1=1.0a s=M/( a 1*fc_b*By*ho*ho) =1056.459/(1.0*14.3*3.000*1.095*1.095*1000) =0.0214. 相對界限受壓區(qū)高度E b=B 1/(1+fy/Es/£ cu)=0.518E =1-sqrt(1- 2 a s)=0.021b=0.5185. 縱向受拉鋼筋A(yù)sx=Asy=a 1*fc_b*By*ho* E /fy=1.0*14.3*3000.000*1095.000*0.021/3602=2708mm 2最小配筋面積 :B=|y1|+C=|-519.6|+600=1