基础工程设计说明书

一 设计资1河床土质：从地面（河床32.5m为软塑粘土，以下为密实粗砂，深42.5m。表1 极限摩阻力内摩擦角容重8×1025×103承台尺寸：7.0m×4.5m×2.0m1.0m。桩身混凝20E2.6104MPa。425m的预应力梁桥，混凝土桥墩，承台顶面上纵桥向荷载为：N0298.8KNM03847.7KN力N0桩（1.0m）

q 1511.78KNN5659.4(7.04.52.025)HM3847.7298.82.04445.3KNh，一般冲刷线以下深度h3N[P]1Ulτ

A{[σ]k

i

2 N8073.23.311.781

计算[P]1.0m1.15m

0.485m2，λ0.70，m0.9，K [σ]

τ

120KPa [P]13.61[2.740(h2.7)120]0.700.90.785[5506.012(h3.33)]Nh2057.17 hh=9m26.2m图 双排桩断面（a）纵桥向断 （b）横桥向断<一>1、桩的计算宽度b1K

K0Kd0.9(d1)K0.911K

3d16m;n2;bKb

0.6

10.6

b10.990.7672、桩的变形系数 mhm2hh

81032.72510322.7α5 1；m1 2 17.25103KN/E0.67E0.672.6107KN/m2I

α

17.251030.672.6107

h=9mhαh0.48994.401l3.3m;h9m;ξ1；A

C10m10251032.5105KN/

2.54.91m

ρ

3.3

l

0.7852.6

2.5105

C0

8.355105hαh0.48994.401 l0αl00.4893.3

ρα3ρα2

4O处位移a0、b0、b0

4

nρρx240.50EI0.977EI41.252 nρ240.031EI0.124EInρ340.107EInρ 2 a 8.185EI298.80.429EI4445.35299.66 2

0.124EI8.185EI0.184EI

xi

β 0.124EI4445.30.429EI298.8 2

0.124EI8.185EI0.184EI

xi

`Pρbxβ0.977EI1851.421.25820.80 i

Qρaρβ0.031EI5299.660.107EI820.80 2 3 Mρβρa0.520EI820.800.107EI5299.66141.50KN 4 3 nQi474.7298.8KNHxiPinMi22810.87806.331.2544445.3KNmMnPi22810.87806.337234.4KNP

M0

Q0

M0MiQil0141.5074.73.3Q0

Mmax

P02810.870.7853.315α

0.489105.000.687

Km

Z1.043

MmaxM0Km105.001.972

x0

x0

Ax

M0

0.4893

2.44066

0.4892

2.644103m2.644mm6mm

AMϕ

0.4892

-

-1.027103Ql 0 Ml

74.73141.50

1.042103m 0

2

8.97

4m

x2.6441.02712.31.04215.43103

[]

2.cm

Z2.132

为M

N2849.7312.13211.78403.612.1321 N

RAr2

Nj

RBr3

μRa

Ra

eMN

4.0

l0.53.3

lp

5.740

0.489

r

1000500mm0.

rggr0.90500μRa

B500AC76.5D 5500B18360CNγb

0.9511A50020.95240 2090000A表2 -53172708270863282708706727082708由计算表可见，当ξ=0.97NuNj之比较为合理，故取ξ=0.97，μ=0.002726为计算值。3Ar20.002726π500210φ18A25.45cm22所示。c602050mm25mm纵向钢筋间净<二>a4

0.94

π

1l

5.7407,

Ah

785398mm

A2545mm NubγRaAhγRgAg 10.95111785398

1240

7030.137KNN

ηeBRaDμgRg ARB11D0.012960.9240A11C0.012965500B1327.95D11A3.110C

ξ0.98

NγbRAr2γbRCμr 0.95112.642450020.952402.36900.007353 6327.73KNNj 0.95110.371750030.952400.63390.007353

484.07KNmMj图 桩承台计算图（尺寸单位承台（3）h02002031

a0

100

a0

0.2

β0x

λ0x

0.565β0y

1.0

λ0y

0.2

βh

0 0

0

0 hpt32371.04KN

c1c2150cm；a1x

2cm

1y

0.

β1x

λ1x

β1y

1.0

λ1y

a1y

a1x

2βhpft 7767.56KN3a

25cm

λ

1000.565，λay

0.14

177cn

βfb

hst0 0.2

1.01100719875.63KNH4MmaxM

Nixi22810.871.50MxNiyi22810.870.75 Asx

1.01770

0.551770

32ϕ2817+29×14+17cm，则实际钢筋=197.02cm2，混凝土保5cmX轴方向布置。

1.0177