发布时间 : 2024/4/30 2:37:18 星期二 文章混凝土课程设计更新完毕开始阅读ea85aa674b35eefdc8d33393

2.框架柱设计

分别选出底层内力组合表中最不利内力，进行配筋计算。

对于弯矩和轴力，承载力抗震系数按轴压比确定，当轴压比小于0.15时，rRE?0.75，当轴压比大于0.15时，rRE?0.80，而剪力的系数都取0.85。 （1）剪跨比和轴压比验算 验算过程如下表33

表33 柱的剪跨比与轴压比验算

层柱2b/mm h0/mm fc/(N/mm) Mc/kN?m Vc/kN 次 号 底A 层 B 400 400 360 360 14.3 14.3 122.67 150.34 46.49 56.99 N/kN 761.42 Mc cVh07.33>2 N fcbh0.333<0.85 0.499<0.85 1027.33 7.33>2 (2)柱正截面承载力验算 C30混凝土：fc?14.3N/mm ft?1.43N/mm ?1?1.0

22HRB335级钢筋：fy?300N/mm2 ?b?0.55

截面尺寸：b?h?400mm?400mm h0?400?40?360mm as?40mm 为了避免柱脚过早屈服，三级框架底层柱下端截面弯矩设计值应乘以增大系数1.3。 A柱：M?0.8?1.3?122.67?127.58kN/m

N?0.8?761.42?609.14kN

M127.58?106e0???209.4mm 3N609.14?10ea取20mm和偏心方向截面尺寸的

400l较大值，即?13.3mm，故取ea=20mm

3030底层柱的计算长度l0?1.0H?4.9m

ei?e0?ea?209.4?20?229.4mm

l04900??12.25?5故应考虑偏心距增大系数? h4000.5fcA0.5?14.3?4002?1???1.88?1.0（取?1?1.0）

N609.14l0?15,取?2?1.0 h1?l0???1????1?2

1400ei/h0?h?2 29

12?12.25??1.17

1400?229.4/360h400e??ei??as?1.17?229.4??40?428.4mm

22?1?xN609.14?103???0.296??b?0.550 对称配筋：??h0?1fcbh014.3?400?3602a's2?40??0.222 ?h0360为大偏心情况

Ne??1fcbh02?(1?0.5?)A's?As?

f'y(h0?a's)609.14?103?428.4?1.0?14.3?400?3602?0.296?(1?0.5?0.296)?

300?(360?40)?770.9mm2?0.002bh?0.002?400?400?320mm2 As?A's?2?770.9?1541.8mm2?0.006bh?960mm2

每侧选用318(As?A's?763mm) 相差小于5% 总配筋量?8?254.34?2035mm?0.008bh?1280mm B柱：M?0.8?1.3?150.34?156.35kN/m N?0.8?1027.33?821.86kN

222M156.35?106e0???190.2mm

N821.36?103ea取20mm和偏心方向截面尺寸的

400l较大值，即?13.3mm，故取ea=20mm

3030底层柱的计算长度l0?1.0H?4.9m

ei?e0?ea?190.2?20?210.2mm

l04900??12.25?5故应考虑偏心距增大系数? h4000.5fcA0.5?14.3?4002?1???1.39?1.0（取?1?1.0）

N821.86l0?15,取?2?1.0 h 30

1?l0???1????1?2

1400ei/h0?h?212?12.25??1.18

1400?210.2/360h400e??ei??as?1.18?210.2??40?408.0mm

22?1?xN821.86?103???0.399??b?0.550 对称配筋：??h0?1fcbh014.3?400?3602a's2?40???0.222 h0360为大偏心情况

Ne??1fcbh02?(1?0.5?)A's?As?

f'y(h0?a's)821.86?103?408.0?1.0?14.3?400?3602?0.399?(1?0.5?0.399)?

300?(360?40)?1026.5mm2?0.002bh?0.002?400?400?320mm2 As?A's?2?1026.5?2053mm2?0.006bh?960mm2

每侧选用322(As?A's?1140mm)‘

总配筋量?8?380?3039mm?0.008bh?1280mm (3)柱斜截面受剪承载力计算 A柱：Mtc222?0.8?105.13?84.1kN?m Mbc?0.8?1.3?122.67?127.58kN?m

框架柱的剪力设计值V?1.2?84.1?127.58?51.89kN

4.9rREV0.85?51.89??0.021?0.2（满足要求）

?cfcbh01.0?14.3?400?360Mc??c?7.33?3（取??3.0）

Vh0N?609.14kN?0.3fcbh?0.3?14.3?400?400?686.4kN

取N?609.14kN

31

Asv?srREV?1.05ftbh0?0.056N??1

fyvh00.85?51.89?103???0

1.05?1.43?400?360?0.056?609.143?1

210?360故该柱应构造配置箍筋

柱端加密区的箍筋选用3肢8

一层柱底的轴压比n=0.333,查表?v?0.0633 最小体积配箍率

?vmin??vfcfyv?0.0633?16.7?0.503%

210Asv?vAcor0.503?350?350???0.293 s?Li100?6?3508 Asv?50.3mm s?172mm

根据构造要求，取加密区箍筋为8@100，加密区长度按规范确定。柱顶850mm,柱底1650mm 非加密区应满足s?15d?15?18?270mm，箍筋取3肢8@200 B柱：Mtc2?0.8?128.89?103.11kN?m Mbc?0.8?1.3?150.34?156.35kN?m

框架柱的剪力设计值V?1.2?103.11?156.35?63.54kN

4.9rREV0.85?63.54??0.026?0.2（满足要求）

?cfcbh01.0?14.3?400?360Mc??c?7.33?3（取??3.0）

Vh0N?821.86kN?0.3fcbh?0.3?14.3?400?400?686.4kN

取N?686.4kN

Asv?srREV?1.05fbh?0.056N??1t0

fyvh00.85?63.54?103???0

1.05?1.43?400?360?0.056?686.43?1

210?36032