钻孔灌注桩计算书

钻孔灌注桩计算书,,,,,,,,,,,

一、已知条件,,,,,,,,,,,

天然地基承载力特征值fak(kPa),,,,800,,,,,,,

"处理后复合地基承载力特征值fsp,k(kPa)",,,,800,,,,,,,

处理后复合地基压缩模量Es(MPa),,,,50,,,,,,,

基础埋深d(m):,,地面下,23.00,有效埋深,21.00,,,,,,

基础型式:,,筏基,,,基础宽度b(m):,,,1.80,长度l(m):,,10.00

地层参数：,,,,,,,,,,,

地层编号,地层名称,侧阻力特征值qs(kPa),端阻力特征值qp(kPa),重度γ(kN/m3),压缩摸量Esi(MPa),厚度(m),厚度(m),厚度(m),厚度(m),厚度(m),厚度(m)

2,,20.0,,18.4,11.2,4.50,,,,,

3,,200.0,,26.0,22.00,4.50,,,,,

4,,200.0,,26.0,32.00,8.50,,,,,

5,,300.0,,26.4,25.00,,,,,,

6,,0.0,,0.0,0.00,0.00,,,,,

7,,0.0,,,,0.00,,,,,

8,,0.0,,,,0.00,,,,,

9,,0.0,,,,0.00,,,,,

10,,0.0,,,,0.00,,,,,

,,,1200,24.05,各孔桩长,17.50,0.00,0.00,0.00,0.00,0.00

,,,,,各孔编号,47,50,51,55,56,57

桩端土强度调整系数：,,,α=,1.00,,桩间土强度调整系数：,,,,β=,0.75

二、设计,,π=,3.1415926,,,,,,,,

1、桩身参数：,,,,,,,,,,,

有效桩长Lp(m):,,17.5,桩径D(m):,,1.80,,,,,,

周长Up(m):,,5.65,面积Ap(m2):,,2.54469,,,,,,

2、单桩承载力特征值：,,,,,,,,,,,

①根据桩身侧阻力及端阻力确定单桩承载力特征值Ra(kN),,,,,,,,,,,

Ra=α·qp·Ap+Up·∑qsi·Li,,,,,,,,,,,

,各孔编号,47,50,51,55,56,,57,,,

,Ra＝,18265,#VALUE!,#VALUE!,#VALUE!,#VALUE!,,#VALUE!,,,

②根据桩体强度确定单桩承载力特征值Ra'(kN),,,,,,,,,,,

fcu≥3Ra/Ap,,,,,,,,,,,

砼立方体抗压强度平均值fcu(kPa):,,,,30000,混凝土等级C,,30,,,,

,,,Ra≤,25446.9,kN,,,,,,

综合①、②取其中小值得,,,,,,,,,,,

最终单桩承载力特征值计算采用值Ra=,,,,,450,kN,,,,,

3、置换率：,,,,,,,,,,,

"fsp,k=m·Ra/Ap+β·(1-m)·fsk",,,,,,,,,,,

经计算得：,,m=,-0.473,,,,,,,,

4、桩距：,,正方形布置,1,正三角形：,,,,,,,

不大于sd(m)=,,#REF!,,,,,,,,,

实际应用sd(m)=,,1.30,,实际置换率m(%)=,,150.50,,,,,

5、实际所需单桩承载力特征值：,,,,,,,,,,,

"Ra=[fsp,k-β(1-m)fsk]·Ap/m",,,,,,,,,,,

,Ra=,1865,kN,,,,,,,,

6、实际复合地基理论特征值：,,,,,,,,,,,

,"fsp,k=",-37,kPa,,,复合地基强度不满足要求,,,,,

7、复合土层压缩模量（各复合土层加权值）：,,,,,,,,,,,

,桩间土的压缩模量ES=,,,24.08,MPa,,,,,,

,复合土层的压缩模量Esp=,,,-1.11,MPa,复合地基压缩模量不满足要求,,,,,

8、下卧层验算（本处指桩端处土层）：,,,,,,,,,,,

下卧层承载力特征值fak'(kPa):,,,,150,扩散角θ(○):,,,,,4,

基底深度修正系数ηd:,,,,1.0,宽度修正系数ηb:,,,,,0.0,

桩端深度修正系数ηd:,,,,1.6,宽度修正系数ηb:,,,,,0.0,

复合地基经修正后的承载力特征值fa(kPa):,,,,,"fsp,k+ηb·γ(b-3)+ηd·γm·(d-0.5)=",,,,,456.09,

桩端处天然土附加压力值pz(kPa):,,,,,lb(p-pc)/(b+2ztgθ)/（l+2ztgθ)=,,,,,129.37,

桩端处天然土自重压力值pcz(kPa):,,,,,（Lp+d)×γ=,,,,,925.76,

桩端处天然土总应力pz+pcz(kPa):,,,,,pz+pcz=,,,,,1055.13,

下卧层经深度修正后的承载力特征值faz(kPa):,,,,,fak'+ηb·γ(b-3)+ηd·γm·(d-0.5)=,,,,,1611.98,

faz与pz+pcz比较结果:,,,,,,该下卧层强度满足要求,,,,,

9、软弱下卧层验算(本工程桩端土下仍存在软弱土)：,,,,,,,,,,,

软弱下卧层承载力标准值fak''(kPa):,,,,150,扩散角θ(○):,,,,,6,

基础底面至软弱下卧层顶面得距离z'(m):,,,,16.0,软弱下卧层深度修正系数ηd:,,,,,1.6,

软弱下卧层顶面处天然土附加压力值pz'(kPa):,,,,,lb(p-pc)/(b+2ztgθ)/（l+2ztgθ)=,,,,,99.13,

软弱下卧层顶面处天然土自重压力值pcz'(kPa):,,,,,（Lp+d)×γ=,,,,,889.69,

软弱下卧层顶面处天然土总应力pz'+pcz'(kPa):,,,,,pz'+pcz'=,,,,,988.82,

软弱下卧层经深度修正后的承载力特征值faz'(kPa):,,,,,fak