m?m1h1?m2(2h1?h2)h2?m3(2h1?2h2?h3)h3hm222
=
12?0.59?3?(2?0.59?3.1)?3.1?18.6?(2?0.59?2?3.1?1.31)?1.3152?9.837
2、桩的变形系数?
??5mb1EI
7EI?0.8ECI EC=2.8?10 KN/m I?0.0491d=0.249 m
2
44
??59783?2.250.8?2.8?10?0.2497=0.352
?h?0.352x27=9.504>2.5 按弹性计算
3. 作用在局部冲刷线处的基本组合值：
M0?1.4M汽?0.6(1.4M制动?1.1M风?1.4M人)
?1.4 ?682,06?0.32?0.6??1.4?45?10.18?1.1?16.25?1.4?13.63??707.25(kN?m)
?0.7(1.4HH?1.1H风）0制动 0.7?(1.4?45?1.1?2.175)? 45.77(kN)?4. 单位“力”作用在局部冲刷线处的，桩柱在该处产生的变位计算
ah?9.504?4，取ah?4.0。
0?B3D4?B4D3?12.441?HH?3??37?EI?A3B4?A4B3?0.352?0.5578?10
?5 ?1.003?10 0?A3D4?A4D3?11.6250?MH??HM?2??27 ?EI?A3B4?A4B3?0.352?0.5578?10?4 ?0.0235?10 0?A3C4?A4C3?11.751?MM???7 ?EI?A3B4?A4B3?0.352?0.5578?10?4 ?0.0089?10
5. 局部冲刷线处变位计算：
00?4?4 X0?H0?HH?M0?HM?45.74?0.1003?10?642.47?0.0235?10 ?1.97?600 ?0???H0?MH?M0?MM ?2??0.0679?10????45.74?0.0235?10?4?642.47?0.0089?10?4?
5
6. 局部冲刷线以下深度各截面内力计算：
?MH1??22MZ??EI?X0A3?0B3?20C3?30D3???EIX0A3??EI?0B3?M0C3?H0D3??EI?EI???
?EIX0?0.352?0.5578?10?0.197?107227?2?0.136?10
?24?EI?0?0.352?0.5758?10???0.0679?101 1H0??45.74?129.94?0.352
???0.1333?104
M?0.136?10A3?0.133?10B3?642.47C3?129.94D3
44由表可知：最大弯矩设计值Md?682.60(kN?m)，Z?1.22m
桩身弯矩图Mz（KN*m）800.00000弯矩Mz（KN*m）600.00000400.00000200.000000.00000azzA3B3C3D3MZ0.571.702.845.117.39-200.00000桩长 Z(m)
桩身弯矩计算表 ?h Z 0.57 1.14 1.70 2.27 2.84 3.98 5.11 6.25 7.39 8.52 9.94 11.36 A3 B3 9.94C3 D3 MZ 0.2 0.4 0.8 1.0 1.2 1.6 1.8 2.0 2.4 3.0 3.6 4.0 -0.00133 -0.01067 -0.08532 -0.16652 -0.28737 -0.67629 -0.95564 -1.69334 -2.62126 -3.54058 -3.91921 -1.61428 -0.00013 -0.00213 -0.03412 -0.08532 -0.17260 -0.54348 -0.86715 -1.90567 -3.59987 -5.99979 -9.54367 -11.7307 0.99999 0.99974 0.99181 0.97501 0.93783 0.73859 0.52997 -0.27087 -1.87734 -4.68788 -10.3404 -17.9186 0.2 0.39998 0.79854 0.99445 1.18342 1.50695 1.61162 1.57538 0.91679 -0.89126 -5.85402 -15.0755 666.81568 682.59806 670.31486 642.64191 595.03603 473.40900 403.54283 262.27773 135.90656 36.89931 -41.11265 -64.66321 7. 轴向力组合计算
Nd?1.2N恒?1.4N汽?0.8?1.4N人 ?1.2?1609.17?1.4?1138.15?0.8?1.4?42.58?3571.89(kN)6
五、桩顶水平位移计算
??X0??0?h1?h2???0 ?0?M外?1?33?h22?nh1?2h2?h1?? nh?h?nh?hh?h?????122112??2EI?E1I1??3?11H式中 ：
h1?4.0
H?45?2.125?47.125KN
E1I1?2.8?10?0.049?1.2?.284?10
n?E1I1EI?(1.21.5)?0.41
4747M外?218.26?458.10?10.81?5.44?692.61
则有： 46.125?0?7 0.284?10 692.61?7 2?0.284?10
?1?330.41?4.0?0?0.41?4.0?0?4.0?0?????3????02?0.41?4.0??2?0?4.0???0.001226?? ??X???h?h???00120 ?2?2?2?0.197?10?0.0679?10?4.0?0??0.123?10 ?2?0.55?10?5.8mm
水平位移容许值????5.027?25.98>5.8,符合要求。
五、桩身配筋计算
1. 按偏心受压构件进行配筋计算 截面设计：
e0? 偏心矩：
MdNd?682.603571.89?0.191me0h00.2260.75?0.88?0.75h0?r?r0
?1?0.2?2.7偏心矩增大系数：
lp?0.7(l0?
?0.2?2.7??0.633 ?1?1.15?0.014lph?1.15?0.01?11.841.54?1.07
?1??1)?0.7?(4.68?0.327)?11.84(m)??1?1400e0/h0(lph)?1?21?(11.841.5)?0.633?1.07
221400?0.226/(0.75?0.88?0.75)7
?1.192 ?e0?1.192?0.226?0.269(m)
主筋采用HRB335级钢筋。 配筋率：
??fcdfsdBr?A(?e0)C(?e0)?Dr0???11.5750B?269A?280269C?660D30.8B?11.05A269C?660D22承载力：
Nu?Arfcd?C?rfsd 22?750?11.5A?750?280C?
?6468750A?157500000C?
ξ A B C -1.2348 D 1.6012 ρ Nu 0.25 0.4473 0.3413 -0.00400 3671.40 当??0.25，计算纵向力Nu略大于设计值Nd?3571.89。 0.000400<0.005，故取??0.005。 所需钢筋面积：
As???r?0.005?750??8831.25(mm)
222钢筋配筋如图所示。
主筋选用18根公称直径为25的HRB335钢筋，实际的配筋率
8836.202??As/?r??0.0052750?箍筋采用螺旋箍筋R235级，直径8mm,螺旋筋的间距S?200mm。 为加强钢筋骨架的刚度，在钢筋骨架上每隔2.5m设置一道直径为
??20mm的加劲箍筋。横系梁高1.2m宽0.9m，采用C25混凝
土，按构造配筋??0.15%
00 As???Acd?0.15%?10800?m16m 2022选取钢筋为6?14?8?12 面积为Asw?1828.2mm箍筋直径为8mm间距为250mm。
8