1、梯板厚: t = 100 mm踏步数: n = 10(阶)上平台楼梯梁宽度: b1 = 200 mm下平台楼梯梁宽度: b2 = 200 mm2荷载标准值:可变荷载:q = 2.50kN/m2面层荷载:qm = 1.70kN/m2栏杆荷载:qf = 0.20kN/m3材料信息:混凝土强度等级: C20fc = 9.60 N/mm2ft = 1.10 N/mm2Rc=25.0 kN/m3钢筋强度等级: HPB235 fy = 210.00 N/mm2抹灰厚度:c = 20.0 mmRs=20 kN/m3梯段板纵筋合力点至近边距离:as = 20 mm支座负筋系数: = 0.25三、计算过程:1楼
2、梯几何参数:踏步高度:h = 0.1500 m踏步宽度:b = 0.3000 m计算跨度:L0 = L1(b1b2)/2 = 2.70(0.200.20)/2 = 2.90 m梯段板与水平方向夹角余弦值:cos = 0.894 2荷载计算( 取 B = 1m 宽板带):(1) 梯段板:面层:gkm = (BBh/b)qm = (110.15/0.30)1.70 = 2.55 kN/m自重:gkt = RcB(t/cosh/2) = 251(0.10/0.890.15/2) = 4.67 kN/m抹灰:gks = RSc/cos = 200.02/0.89 = 0.45 kN/m恒荷标准值:Pk
3、 = gkmgktgksqf = 2.554.670.450.20 = 7.87 kN/m恒荷控制:Pn(G) = 1.35gk1.40.7q = 1.357.871.40.72.50 = 13.07 kN/m活荷控制:Pn(L) = 1.2gk1.4q = 1.22.50 = 12.94 kN/m荷载设计值:Pn = max Pn(G) , Pn(L) = 13.07 kN/m3正截面受弯承载力计算:左端支座反力: Rl = 18.95 kN右端支座反力: Rr = 18.95 kN最大弯矩截面距左支座的距离: Lmax = 1.45 m最大弯矩截面距左边弯折处的距离: x = 1.45 m
4、Mmax = RlLmaxPnx2/2 = 18.951.4513.071.452/2 = 13.74 kNm相对受压区高度:= 0.256555 配筋率:= 0.011728纵筋(1号)计算面积:As = 938.26 mm2支座负筋(2、3号)计算面积:As=As = 0.25938.26 = 234.56 mm2四、计算结果:(为每米宽板带的配筋)11号钢筋计算结果(跨中)计算面积As:938.26 mm2采用方案:d12100实配面积:1130.97 mm222/3号钢筋计算结果(支座)计算面积As:234.56 mm2d6100282.74 mm234号钢筋计算结果d6250113.10 mm2