3.5.2.框架柱 3.5.2.1轴压比验算:
由《建筑抗震设计规范》查得本工程属四级 抗震,对柱的轴压比不作要求。 3.5.2.2截面尺寸复核:
取ho=450-35=415mm。Vmax=62.242KN
则0.25?fcbh0?0.25?1.0?14.3?450?415?676.97kN?Vmax,满足要求。 3.5.2.3框架柱正截面承载力计算
以底层的 B柱为例。由B柱内力组合表,考虑到柱端弯矩较小,支座中心处的弯矩与支座边缘的弯矩偏差不大,且按支座中心算是偏于安全的,故采用对称配筋。 B轴柱:
Nb??1fcbh0?b?1.0?14.3?450?415?0.518?1383.33kN (?b=0.518) 选最不利组合:
KNm KNm KNm?M?93.241?M?88.232?M?52.059 柱顶:①?, ②?, ③?
KN KN KN?N?2129.718?N?1796.588?N?2293.309 KNm KNm KNm?M?79.694?M?80.484?M?27.381柱底:①? ,②?, ③?
N?2151.594 KNN?1818.464 KNN?2317.920 KN???以第一种不利组合为例计算: 柱顶:Nb﹤N为小偏心受压,
?1??sfc?AN0.5?14.3?4502??0.680 32129.718?10l0/h?4650?10.33?15,取ζ2=1.0 450M93.24?106e0???43.781mm
N2129.718?103ea?20mm(﹥
h450??15mm) 3030ei?e0?ea?43.718?20?63.718mm
??1?l1?(0)2?1?2?1??10.332?0.680?1.0?1.323 eih63.7181400?1400?410h01
e??ei?h450??s?1.323 ?63.718??35?274.711mm 22对称配筋:??N??b?1fcbh0Ne?0.43?1fcbh0??1fcbh0'(?1??b)(h0??s)2??b?0.721 (?1?0.8)
As?As'?Ne??1fcbh0?(1?0.5?)2 ?536.7 mm''fyh0??s??柱底:Nb﹤N为小偏心受压,
?1??sfc?AN0.5?14.3?4502??0.673 2151.594 ?103l0/h?10.33?15,取ζ2=1.0
M79.694 ?106e0???37.040 mm 3N2151.594 ?10ea?20mm(﹥
h450??15mm) 3030ei?e0?ea?37.040?20?57.040mm
??1?l1?(0)2?1?2?1??10.332?0.673?1.0?1.358 eih57.0401400?1400?410h01h450??s?1.358?57.040??35?267.460 mm 22e??ei???N??b?1fcbh0Ne?0.43?1fcbh0??1fcbh0(?1??b)(h0??s')2??b?0.732 (?1?0.8)
As?As'?Ne??1fcbh0?(1?0.5?)2 ?447.3 mm''fyh0??s??As min=0.002bh=0.002×450×450=405mm2 其他各柱正截面受弯承载力计算如下表:
表3.11柱正截面受弯承载力计算表
3.5.2.4垂直于弯矩作用平面的受压承载力验算 按轴心受压构件验算:Nmax?2283.82KN
l05.45??9.91 查表的:??0.981 b0.550.981×(14.3×550×550+360×12×153.9)=4406.2KN﹥Nmax Nu?0.9?(fcA?fy'As')?0.9×满足要求。
3.5.2.5斜截面受弯承载力计算
?M?88.98KNm?以B轴柱为例 一层最不利组合 ?N?1716.6KN
?V?28.63KN?剪跨比??hn4.90??4.80﹥3 (取??3) 2h02?0.510.3fcA?0.3?14.3?5502=1297.7KN﹤N 取N=1297.7KN
Asv?sV?1.751.75ftbh0?0.07N28.63?103??1.43?550?510?0.07?1297.7?103??13?1?﹤0
fyvh0210?510按构造配筋。取井字形复式箍 ?8@20 0其余各柱斜截面受剪承载力计算 如下表
表3.12柱斜截面受剪承载力计算表 柱号 A4-A3 A3-A2 A2-A1 A1-A0 B4-B3 B3-B2 B2-B1 B1-B0 C4-C3 C3-C2 C2-C1 C1-C0
控制内力 V(KN) N(KN) 22.01 289.54 23.78 714.28 26.88 1142.68 17.1 1577.45 13.02 503.3 17.49 1094.1 23.93 1684.16 28.63 1716.6 5.5 291.88 12.71 562.93 19.19 833.99 26.89 1113.67 柱斜截面受剪承载力计算 斜截面抗剪承载力计算 Hn ho λ Asv/s 3950 360 3 0 3950 360 3 0 3950 360 3 0 4900 360 3 0 3950 510 3 0 3950 510 3 0 3950 510 3 0 4900 510 3 0 3950 510 3 0 3950 510 3 0 3950 510 3 0 4900 510 3 0 实配钢筋 Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4) Ф8@200(n=4)