?取?s??s=40mm h0?h?as=560mm
e0?M/N?30mm ea?20mm ?ei?ea?e0?50mm 15?l0/h?10?5 ?要考虑?
?1?0.5fcA/N?0.5?14.3?300?600/260?10?4.95?1 取?1?1
取?2?1.0
3??1?11400ei/h0(l0/h)?1?2?1?211400?50/560(10)?1?1.8
2??ei?1.8?50?90?0.3h0?0.3?560?168mm 属于小偏心受压
由
??N?a1fcbh0?bNe?0.43a1fcbh02??b(?1??b)(h0?as?)???3?a1fcbh032600?10?0.518?14.3?300?5602600?10?330?0.43?14.3?300?560(0.8?0.518)?52022?0.518?1.183?14.3?400?560
2As?As??Ne?a1fcbh0?(1?0.5?)/fy?(h0?as?)?1097.6mm?0.02bh选用4
2?20As?1256mm
抗压承载力验算：
???As?/bh0?1256/300?560?0.7500?300
3?Nu?0.9?(fcA?fy?As?)?0.9?0.98?(14.3?400?600?360?1256)?2.67?10kN?2600kN 所以平面外承载力满足要求。
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