k?Fk?Gkn?6749?6724?1855.25?Ra?2092kN
2iQkmax?kminFk?Gkn?(Mxk?HykH)ymax2i??y?(Myk?HxkH)xmax?x?
?6749?6724?116.5?7?1.3??1.24?1.22?183.5?72?1.3??1.24?1.22
?1855.25?23.38?57.73
15
= 1936.36<1.2Ra?2510.4kN
1774.14>0
1.1QFk?Gkk?n?1.1?2041?1.25Ra?2615kN 1.1Qkmax?1936.36?1.1?2130?1.5Ra?3138kN
②单桩水平承载力验算
单桩水平承载力特征值Hha?148.5 kN
H1k?Hkn?72/4?18kN ≤Hha?148.5
kN 可以满足要求。
(4)桩身结构承载力验算
桩身的材料是C30
Ap?14?3.14?0.82?0.5024m2fN/mm2c?14.3
A3pfc?c?0.5024?14.3?10?0.6?4311KN?1.35Ra?2824KN(5)承台设计 ①桩顶反力计算
相应于荷载效应基本组合时,作用于柱底的荷载设计值为:F?1.35Fk?1.35?6749?9111.15kN Mx?1.35Mxk?1.35?116.5?157.28 kN·m My?1.35Myk?1.35?183.5?247.73kN·m Vx?1.35Vxk?1.35?72?97.2KN·m
Vy?1.35Vyk?1.35?(?7)??9.45kN·m
N?F?1.35n?67494?2778kN
N)ymaxMyk?HxkH)xmaxmax?FMxk?HykHminn?(?y2?(i?x2
i
16
?6749?1.354??183.5?7?1.3??1.24?1.22?1.35??116.5?72?1.3??1.24?1.22?1.35
?2278?59.1?49.1
= 2386.2 2169.2
桩顶反力计算
桩号 1 2 3 4 Fn (Mxk?HykH)ymax2i?y (Myk?HxkH)xmax?x2i Ni(kN) 2278 2278 2278 2278 -59.1 -59.1 59.1 59.1 49.1 -49.1 49.1 -49.1 2268 2169.8 2386.2 2288 ②承台受冲切承载力验算 (a)柱边冲切 冲切力
Fl?F??Ni?9111.15?0?9111.15kN
受冲切承载力截面高度影响系数?计算
hp?hp?1?1.0?0.902000?800??1300?800??0.958
冲跨比?与系数?的计算
?0x??0x??0y??0y?
a0xh0?0.581.23??0.472??1.0? 0.840.472?0.2?1.25
0.84?0x?0.2a0yh0?0.481.23??0.390??0.20? 0.840.390?0.2?1.424
17
0.84?0y?0.2
2?0x?a?a0y???0y?b?a0x??hpfth0
?2??1.25??0.8?0.48??1.424??0.6?0.58???0.958?1430?1.23
?11055??kN>Fl?9111.15kN (满足要求)
(b)角桩向上冲切
c1?c2?1.12m,a1x?a0x,?1x??0x,a1y?a0y,?1y??0y
?1x??1y?0.56?1x?0.20.56?0.560.472?0.20.560.390?0.2?0.833
?0.949
?1y?0.2????c1x2?a1y/2???1y?c1?a1x/2??hpfth0
???0.833??1.12?0.48/2??0.949??1.12?0.58/2???0.958?1430?1.23?4164kN>Nmax?2386.2kN (满足要求)
③承台受剪切承载力计算 剪跨比与以上冲跨比相同。
受剪切承载力截面高度影响系数?hs计算:
?hs?800???h?0????1/4?800????1230??14?0.898
对Ⅰ-Ⅰ斜截面
?1x??0x?0.472(介于0.3~3之间) 剪切系数 ??1.750.472?1?1.188
?hs?ftb0h0?0.898?1.188?1430?4.0?1.23
?7506kN>2Nmax?4772.4kN (满足要求)
对Ⅱ-Ⅱ斜截面
18
?1y??0y?0.390??0.20? 剪切系数 ??1.750.390?1?1.258
?hs?ftb0h0?0.898?1.258?1430?4.0?1.23
?7948kN>2Nmax?4772.4kN (满足要求)
④承台受弯承载力计算
My??NMixi?2?2386?0.90?4294.8kN·m
Asy?y0.9fyh0?4294.8?1060.9?360?1230?10990?10777mm2
选用35 20@110,AsMxmm2,沿平行x轴方向均匀布置。
??NMiyi?2?2386?0.8?3817.6kN·m
Asx?x0.9fyh0?3817.6?1060.9?360?1210?10048?9738mm2
选用31 20@120,Asmm2,沿平行y轴方向均匀布置。
⑤局部受压计算
承台混凝土强度等级低于柱和桩的混凝土强度等级,应按《混凝土结构设计规范》验算柱下和桩上承台的局部受压承载力,柱的混凝土强度等级C60,承台的混凝土强度等级C30,需要局压验算:
柱局压验算:
Ab??a?b??3b??0.8?2?0.6??3?0.6?3.6m2
Al?ab?0.8?0.6?0.48m2
2 ?l?AbAl?3.60.48?2.74fcc?0.85fc?0.85?14.3?12.155N/mm
19
Fl?w?lfccAl?1?2.74?12.155?10?0.48?15986KN3>
1.35?6749?9111.15KN
桩局压验算:不需要验算 柱对承台局压验算满足 桩对承台局压验算满足 (6)桩基沉降
柱①按有扩散计算
?qsiali(?18.1x1.7?15.1x4.3?18.9x2.9?18.5x3.9?15.5x6.0?17.5?5.1?20?1.1?21?1.8)?464.71
Pok?Pk??c?Fk?GkA??c?5288?19?(3.2?2?25.2?tan8)?(3.2?2?25.2?tan8)?(2.1?25.2)(3.2?2?25.2?tan8)?(3.2?2?25.2?tan8)???? (-18.1x1.7?15.1x4.3?18.9x2.9?18.5x3.9?15.5x6.0?17.5?5.1?20?1.1?21?1.8) ?103.39KPa
?
Z1?0Z2?1.0 zbLb?1(3.2?2?25.2?tan8)2?0.1945???0.2496
?1?S??b??Pok?103.39??4??1.0?0.2496?0??2.8mm?0.002?4800?9.6mm?4Z2??4Z?1??0.4Esi?15?按不扩散计算
?2?