y (m) (m) (kN*m) 0 0.301 0.602 0.903 1.204 1.506 1.807 2.108 2.409 2.710 3.011 3.312 3.613 3.914 4.216 4.517 4.818 5.119 5.420 5.721 6.022 6.625 7.227 7.829 8.431 9.033 10.539 12.045 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.2 2.4 2.6 2.8 3 3.5 4 0.00000 0.00000 1.00000 0.00000 2785.0 -0.00017 -0.00001 1.00000 0.10000 2901.2 -0.00133 -0.00013 0.99999 0.20000 3010.9 -0.00450 -0.00067 0.99994 0.30000 3108.4 -0.01067 -0.00213 0.99974 0.39998 3189.6 -0.02083 -0.00521 0.99922 0.49991 3251.3 -0.03600 -0.01080 0.99806 0.59974 3291.1 -0.05716 -0.02001 0.99580 0.69935 3307.8 -0.08532 -0.03412 0.99181 0.79854 3300.7 -0.12144 -0.05466 0.98524 0.89705 3270.5 -0.16652 -0.08329 0.97501 0.99445 3217.4 -0.22152 -0.12192 0.95975 1.09016 3142.8 -0.28737 -0.17260 0.93783 1.18342 3048.4 -0.36496 -0.23760 0.90727 1.27320 2936.1 -0.45515 -0.31933 0.86573 1.35821 2808.1 -0.55870 -0.42039 0.81504 1.43680 2679.4 -0.67629 -0.54348 0.73859 1.50695 2514.8 -0.80848 -0.69144 0.64637 1.56621 2354.3 -0.95564 -0.86715 0.52997 1.61162 2187.8 -1.11796 -1.07357 0.38503 1.63969 2017.7 -1.29535 -1.31361 0.20676 1.64628 1846.4 -1.69334 -1.90567 -0.27087 1.57538 1508.0 -2.14117 -2.66329 -0.94885 1.35201 1187.5 -2.62126 -3.59987 -1.87734 0.91679 896.3 -3.10341 -4.71748 -3.10791 0.19729 643.1 -3.54058 -5.99979 -4.68788 -0.89126 433.4 -3.91921 -9.54367 -10.34040 -5.85402 109.7 -1.61428 -11.73066 -17.91860 -15.07550 53.1 y＝2.108m处，弯矩最大，My＝3307.8 kN?m
垂直力： Nd＝2834.4＋202.5/2＋?×1.5×2.108×25＝
2
43028.8kN 2、截面配筋计算
偏心矩： e0＝Md/Nd＝3307.8/3028.8＝1.092m 构件计算长度：l0＝0.7×4＝0.7×
?4＝8.431m 0.3321
i＝
IA＝
??1.54/64＝0.375 2??1.5/4 l0/i＝8.431/0.375＝22.48>17.5 ∴应考虑偏心矩增大系数η η＝1＋
l1(0)2?1?2
1400e0/h0hh0＝r＋rs＝0.75+0.66＝1.41m h＝2r＝2×0.75＝1.5m
ξ1＝0.2＋2.7e0＝0.2+2.7×1.092＝1.09>1.0
h01.41∴取 ξ1＝1.0
ξ2＝1.15－0.01
1.094〉1.0 ∴取 ξ2＝1.0
η＝1＋
18.4312()?1.0?1.0＝1.029
1400?1.092/1.411.5l0h＝1.15－0.01×
8.4311.5
＝
ηe0＝1.029×1.092＝1.124m
由公路钢筋混凝土及预应力混凝土桥涵设计规范(JTG D62-2004)附录C有 配筋率 ρ＝
fcdBr?Ae0 ?fsd'Ce0?Dgrfcd＝11.5MPa fsd’ ＝280MPa
g＝rs/r＝0.66/0.75＝0.88 假定ξ＝0.32，
A＝0.6351，B＝0.4433，C＝-0.8656，D＝1.7721 ρ＝11.5?0.4433?0.75?0.6351?1.124280?0.8656?1.124?1.7721?0.88?0.75＝0.00731
N2
2
d≤Arfcd＋Cρrfsd’
Ar2
f2
2
cd＋Cρrfsd’＝0.6351×0.75×11.5×
103
-0.8656×0.00731×0.752
×280×103
＝3111.7kN>Nd＝3028.8Kn ∴纵向钢筋面积
A2
s＝ρπr＝0.00731×π×0.752
＝0.01292m
2
选用28φ25HRB335钢筋，A＝0.001374m2
> As＝0.01292m2