桥墩承台计算

1、承台底面单桩竖向力设计值简化算法承台底面单桩竖向力设计值按下列公式计算:1)、参数说明：Nid第i根桩的单桩竖向力设计值Fd由承台底面以上的作用产生的竖向力组合设计值(kN)Myd由承台底面以上的作用绕通过桩群形心的y轴的弯矩组合设计值(kN*m)Mxd由承台底面以上的作用绕通过桩群形心的y轴的弯矩组合设计值(kN*m)n承台下面桩的总根数xi、yi第i根桩中心至y轴、x轴的距离2)、数据输入:桩基坐标(请选填)单位：mx-2x-1x0x1x2Σxi2纵桥向排数nFd220162411865.2y-2y-1y0y1y2Σyi2横桥向排数MydMxd2216210385.0603)、单桩最大竖向力设计值:Ndmax=4264.4图8.5.1如下：22ydidxdiidiiMxFMyNnyx11865.210383.53)、详细计算过程(见下页）①、基本数据输出3D=3×1.2=3.6M5.4Mbs=7.9-(5.4-3D)(n-1)∴承台截面计算宽度bs=6.1m桩的支撑宽度b=0.8×1.2=0.96m当外排桩中心距墩台身边缘等于或小于承台高度时，承台短悬臂可按“撑杆—系杆体系”计算:h0=2.116s=0.534ha=s+6d=0.726a=0.15×h0=0.3174θ1=tan-1[h0/(a+x1)]=0.69898rad=40.0487°单位EcEsMPa13.8301.392803.00E+042.00E+05②、撑杆抗压承载力检算1.1×2×4100/sin40.0487°=14018kN0.96×sin40.0487°+0.726×cos40.0487=1.173mAs=(π×32×32/4/1000000)(19/7.9×6.1)×3=0.03539708㎡2×4100/tan40.0487°=9756kN0.0047812710.4MPa=14.4取10.4MPa∴1.173×6.1×10.4×1000=74415kN14018kN富余430.9%③、系杆抗拉承载力检算1.1×9756=10731.6kN280000×0.035397=9911kN10731.6kN不足-7.6%④、斜截面抗剪承载力检算0,idscdsDtbf公式:,cukfcdftdfsdf001/sinididDnN11sincosatbh21(0.002)cotidissTAE1/tanididTnN,,11.43304cukcdsff,0.48cukf,cdsf,scdstbf0idsdsTfA公式:0idTsdsfA40,00.910(20.6)/dcuksVPfbhm公式:00didVnN1.1×2×4100=9020kN100×0.035397/(7.9×2.116)=0.21175062(2.2-0.96/2)/2.116=0.8128544420.5取0.81285444216650kN9020kN余84.6%⑤、冲剪承载力检算a、角桩(7.9-1×5.4+0.96)/2=1.732.116m0.4232m2.2-0.96/2=1.72m2.116m取1.72m0-0.96/2=-0.48m0.4232m取0.4232m0.8128544420.789846960.2211848kN1.1×4100=4510kN11848余162.7%b、边桩0.9610385kN或:15428kN4510kN10385kN余130.3%00didVnN0100100/sPAbh0/ximah4,00.910(20.6)cuksPfbhm000.6[(/2)()]ldtdpxyypyxxFfhbaba公式:yxbbxa0hya00.2h0/xxah0/yyah0.80.2pxx0.80.2pyy00.6[(/2)()]tdpxyypyxxfhbaba0ldF0000.6[()0.667(2)]ldtdpxpxxFfhbhba0000.6[()0.667(2)]ldtdpypyyFfhbhbapb0ldF33'cdsdBrfDgrf12[]()aPcAcUhRt