梯梁、梯柱、计算书示意图：三、基本资料：1.根据法律规范：《建筑构造荷载法律规范》（GB 50009－）《混凝土构造设计法律规范》（GB 50010－）2.几何参数：楼梯净跨: L1 = 2240 mm楼梯高度: H = 1400 mm梯板厚: t = 160 mm踏步数: n = 9(阶)上平台楼梯梁宽度: b1 = 200 mm下平台楼梯梁宽度: b2 = 200 mm下平台宽: L2 = 2110 mm上平台宽: L3 = 300 mm3.荷载原则值：可变荷载：q = 3.50kN/m2面层荷载：qm = 2.00kN/m2栏杆荷载：qf = 0.30kN/m永久荷载分项系数: γG = 1.20可变荷载分项系数: γQ = 1.40准永久值系数: ψq = 0.504.材料信息：混凝土强度等级: C30fc = 14.30 N/mm2ft = 1.43 N/mm2Rc=25.0 kN/m3ftk = 2.01 N/mm2Ec = 3.00×104 N/mm2钢筋强度等级: HRB400 fy = 360 N/mm2 Es = 2.00×105 N/mm2保护层厚度：c = 20.0 mmRs=20 kN/m3受拉区纵向钢筋类别：光面钢筋梯段板纵筋合力点至近边距离：as = 20.00 mm支座负筋系数：α = 0.25计算过程：1. 楼梯几何参数：踏步高度：h = 0.1556 m踏步宽度：b = 0.2800 m计算跨度：L0 = L1＋L2＋L3＋(b1＋b2)/2 = 2.24＋2.11＋0.30＋(0.20＋0.20)/2 = 4.85 m梯段板与水平方向夹角余弦值：cosα = 0.874 2. 荷载计算( 取 B = 1m 宽板带)：(1) 梯段板：面层：gkm = (B＋B*h/b)*qm = (1＋1*0.16/0.28)*2.00 = 3.11 kN/m自重：gkt = Rc*B*(t/cosα＋h/2) = 25*1*(0.16/0.874＋0.16/2) = 6.52 kN/m抹灰：gks = RS*B*c/cosα = 20*1*0.02/0.874 = 0.46 kN/m恒荷原则值：Pk = gkm＋gkt＋gks＋qf = 3.11＋6.52＋0.46＋0.30 = 10.39 kN/m恒荷控制：Pn(G) = 1.35*Pk＋γQ*0.7*B*q = 1.35*10.39＋1.40*0.7*1*3.50 = 17.46 kN/m活荷控制：Pn(L) = γG*Pk＋γQ*B*q = 1.20*10.39＋1.40*1*3.50 = 17.37 kN/m荷载设计值：Pn = max{ Pn(G) , Pn(L) } = 17.46 kN/m(2) 平台板：面层：gkm' = B*qm = 1*2.00 = 2.00 kN/m自重：gkt' = Rc*B*t = 25*1*0.16 = 4.00 kN/m抹灰：gks' = RS*B*c = 20*1*0.02 = 0.40 kN/m恒荷原则值：Pk' = gkm'＋gkt'＋gks'＋qf = 2.00＋4.00＋0.40＋0.30 = 6.70 kN/m恒荷控制：Pl(G) = 1.35*Pk'＋γQ*0.7*B*q = 1.35*6.70＋1.40*0.7*1*3.50 = 12.48 kN/m活荷控制：Pl(L) = γG*Pk＋γQ*B*q = 1.20*6.70＋1.40*1*3.50 = 12.94 kN/m荷载设计值：Pl = max{ Pl(G) , Pl(L) } = 12.94 kN/m
