橋臺計算-承臺樁基2

U臺承臺樁基摩擦樁樁長驗算,,,,,,,

一、設計資料,,,,,,,

跨徑,16,m,路寬,12,m,,

臺高,3,m,臺長,4.5,m,,

,,,,,,,,

樁長,30,m,,,,,

樁徑,1.4,m,,,,,

樁排數（縱）,2,,縱向樁間距,3.65,m,,

樁排數（橫）,3,,橫向樁間距,4.55,m,,

,,,,,,,,

二、上部及臺身、承臺傳來荷載,,,,,,,

1.水平力,H=,2078.810,KN,,,,

2.豎直力,N=,10086.136,KN,,,,

3.彎矩,M=,10406.172,KN·m,,,,

,,,,,,,,

三、單樁軸向壓力,,,,,,,

1.樁的計算寬度b1=,,Kf·K0·K·d=,0.9(d+1)K=,1.854,m,,

,式中K=,b'+(1-b')L1/0.6h1=,0.792307692,,,,

,b'=,0.6,,,,,

,L1=,2.25,m,,,,

,h1=,7.8,m,,,,

2.樁的變形系數α=5√mb1/EI=,,,0.303,m-1,,,

,式中m=,5000,KN/m4,,,,

,En=,2.85E+07,Kpa,,,,

,I=,0.188574099,m4,,,,

3.ρ1、ρ2、ρ3、ρ4值的計算,,,,,,,

⑴.ρ1=,1,,=,1021410.286,=,0.283660277,EI

,(lo+ξh)/A·Eh+1/C0A0,,,,,,

,式中l(wèi)o=,0,m,,,,

,ξ=,0.5,,,,,

,A=,1.5393804,m2,,,,

,Co=,150000,KN·m3,,,,

,Ao=,10.46346703,m2,,,,

,,,,,,,,

已知,h1=αh=,9.1045,,,,,

,l01=αl0=,0,,,,,

查表,17、18、19,（P239~241）,,,,,

,xQ=,1.06423,,,,,

,xm=,0.98545,,,,,

,φm=,0.48375,,,,,

,,,,,,,,

⑵.ρ2=,α3EIXQ=,0.029746941,EI,,,,

⑶.ρ3=,α2EIXm=,0.090762365,EI,,,,

⑷.ρ4=,αEIφm=,0.14681032,EI,,,,

,,,,,,,,

4.承臺底面座標原點O處位移a0、b0、β0值的計算,,,,,,,

⑴.b0=,N/(n·ρ1)=,5926.18312,/EI,,,,

⑵.a0=,(nρ4+ρ1Σxi2)·H+n·ρ3·M,,=,22102.3384,/EI,,

,nρ2·(nρ4+ρ1Σxi2)-n2ρ32,,,,,,

,式中nρ4+ρ1Σxi2=,6.54945798,EI,,,,

,nρ2=,0.178481647,EI,,,,

,nρ3=,0.544574193,EI,,,,

,n2ρ32=,0.296561051,(EI)2,,,,

⑶.β0=,nρ2·M+n·ρ3·H,,=,3426.624806,/EI,,

,nρ2·(nρ4+ρ1Σxi2)-n2ρ32,,,,,,

,,,,,,,,

5.作用于每根樁上荷載Pi、Qi、Mi的計算,,,,,,,

⑴.豎向力,Pi=,ρ1(b0+xiβ0)=,3454.917895,KN,,,

,,,-92.8724032,KN,,,

⑵.水平力,Qi=,ρ2a0-ρ3β0=,346.4683883,KN,,,

⑶.彎矩,Mi=,ρ4β0-ρ3a0=,-1502.996632,KN·m,,,

,,,,,,,,

6.校核,,,,,,,

⑴.,nQi=,2078.81033,,(H),,,

⑵.,ΣXiPi+nMi=,9389.219281,,(M),,,

⑶.,ΣnPi=,10086.13648,,(N),,,

,,,,,,,,

7.單樁軸向作用力,,,,,,,

P1=,4609.45,KN,,,,,

,,,,,,,,

三、樁的計算,,,,,,,

1.計算取值,,,,,,,

極限摩阻力τp,,35,Kpa,,,,

容許承載力[σ0],,200,KPa,,,,

樁的周長U,,5.027,m,,,,

樁在沖刷線下有效長度l:,,30.000,m,,,,

樁底橫截面面積A,,1.539,m2,,,,

樁尖極限承載力σR,,2577.4,KPa,,,,

修正系數,,,,,,,

m0=,0.7,,,,,,

λ=,0.7,,,,,,

k2=,5,,,,,,

γ2=,18,KN/m3,,,,,

h=,30.000,m,（樁尖埋置深度）,,,,

,,,,,,,,

2.樁的容許承載力,,,,,,,

[P]=,1/2(Ulτp+AσR)=,,4622.74,KN,,,

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