重力坝设计例题—荷载计算讲解.ppt

重力坝荷载计算案例

三、计算实例案例资料

大坝实用剖面图

荷载计算简图坝体自重计算静水压力泥沙压力浪压力计算扬压力计算

坝体自重计算W1=1/2×24×21×21×0.2×1=1058.4(kN)力臂=28.56/2－2/3×21×0.2=11.48(m)坝顶宽度=(34.8－28.8)×0.7=4.2(m)坝基宽度=34.8×0.7+21×0.2=28.56(m)力矩=1058.4×11.48=12150.432(kN?m)W2=24×4.2×34.8×1=3507.84(kN)力臂=28.56/2－21×0.2－4.2/2=7.98(m)力矩=3507.84×7.98=27992.563(kN?m)W3=1/2×24×28.8×28.8×0.7×1=6967.296(kN)力臂=28.56/2－28.8×0.7×2/3=0.84(m)力矩=－6967.296×0.84=－5852.529(kN?m)回计算简图

静水压力计算PH1=1/2×9.81×33×33×1=5341.545(kN)力臂=1/3×33=11.0(m)力矩=－5341.545×11.0=－58756.995(kN?m)PH2=－1/2×9.81×2.1×2.1×1=－21.631(kN)力臂=1/3×2.1=0.7(m)力矩=21.631×0.7=15.142(kN?m)PV1=9.81×(33－21)×21×0.2=494.424(kN)力臂=28.56/2－21×0.2/2=12.18(m)力矩=494.424×12.18=6022.084(kN?m)PV2=1/2×9.81×21×21×0.2=432.621(kN)力臂=28.56/2－21×0.2/3=12.88(m)力矩=432.621×12.88=5572.158(kN?m)PV3=1/2×9.81×2.1×2.1×0.7=15.142(kN)力臂=28.56/2－2.1×0.7/3=13.79(m)力矩=－15.142×13.79=－208.805(kN?m)回计算简图

回计算简图泥沙压力计算PsH=1/2×6.5×11.1×11.1×tan2(45－18/2)=211.374(kN)力臂=1/3×11.1=3.7(m)力矩=－211.374×3.7=－782.084(kN?m)PsV=1/2×6.5×11.1×11.1×0.2=80.087(kN)力臂=28.56/2－11.1×0.2/3=13.54(m)力矩=80.087×13.54=1084.378(kN?m)

回计算简图浪压力计算计算风速V0=1.5×12=18(m/s)，D=900(m)hL=0.59(m)，Lm=6.88(m)由于gD/V02=27.25，hL=h5%，h1%=1.241h5%=0.737，hZ=0.248。Hcr=0.89，H=33Hcr，且HLm/2，深水波PL=1/4×9.81×6.88×(0.737+0.248)=16.62(kN)力矩=－16.62×33=－548.36(kN?m)

回计算简图扬压力计算U1=－9.81×2.1×28.56×1=－588.365(kN)力臂=0(m)力矩=0(kN?m)U2=－9.81×6.9×0.25×(33－2.1)=－522.898(kN)力臂=28.56/2－6.9/2=10.83(m)力矩=－5662.98(kN?m)U3=－9.81×1/2×(28.56－6.9)×0.25×(33－2.1)=－820.722(kN)力臂=2/3×(28.56－6.9)－28.56/2=0.16(m)力矩=－131.32(kN?m)U4=－9.81×1/2×6.9×(1－0.25)×(33－2.1)=－784.346(kN)力臂=28.56/2－1/3×6.9=11.98(m)力矩=－9487.70(kN?m)

荷载作用标准值作用设计值力臂(m)弯矩标准值(kN·m)弯矩设计值(kN·m)垂直荷载(kN)水平荷载(kN)垂直荷载(kN)水平荷载(kN)自重W11058.401058.4011.4812150.4312150.43W23507.843507.847.9827992.5627992.56W36967.306967.30-0.84-5852.53-5852.53水平水压力PH15341.555341.55-11.0-58757.00-58757.00PH2-21.63-21.63-0.7015.1415.14垂直水压力PV1494.42494.4212.186022.086022.08PV2432