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梁式楼梯计算书(示例)

梁式楼梯计算项目名称_____________日期_____________设计者_____________校对者_____________一、工程名称: LT-1二、示意图三、基本资料1.依据规范:《建筑结构荷载规范》(GB50009-2012)《混凝土结构设计规范》(GB 50010-2010)2.几何参数:楼梯类型:梁式楼梯(__╱ 型)支座条件:两端固定斜梯段水平长度: L1 = 1400 mm 下平台长度: L3 = 1220 mm梯段净跨: L n = L1+L3 = 1400+1220 = 2620 mm楼梯高度:H = 960mm 楼梯宽度:W = 1800 mm梯板厚:t = 100 mm 楼梯级数:n = 6(阶)踏步宽度: b = 280 mm 踏步高度:h = 160 mm上平台楼梯梁宽度: b1 = 400 mm 下平台楼梯梁宽度: b2 = 400 mm 楼梯梁高度:h3 = 450 mm 楼梯梁宽度: b3 = 200 mm水平段楼板厚度: h4 = 100 mm3.荷载标准值:可变荷载:q = 3.50kN/m2面层荷载:q m = 1.50kN/m2栏杆荷载:q f = 1.00kN/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: C30 f c = 14.30 N/mm2f tk = 2.01 N/mm2f t = 1.43 N/mm2梯梁纵筋强度等级: HRB400 E S = 200000 N/mm2f y = 360.0 N/mm2受拉区纵向钢筋类别:带肋钢筋其余钢筋选用HPB300钢f yv = 270.0 N/mm2保护层厚度: c = 30 mm顶棚厚度 c1= 20mm 顶棚容重 R s=20.0 kN/m3混凝土容重 R c=25.0 kN/m3混凝土弹性模量 E c= 3.00×104 N/mm2钢筋弹性模量 E s= 2.0×105 N/mm2梯段板纵向受力钢筋合力点至近边距离a s1 = 40 mm梯梁纵向受力钢筋合力点至近边距离a s2 = 40 mm四、计算过程:说明:本计算书中所有的剪力、弯矩、挠度均由《建筑结构静力计算手册》中单跨梁的内力及变位计算公式所得。

1.楼梯几何参数:梯段倾角余弦值:cosα = b/sqrt(b2+h2) = 280.00/sqrt(280.002+160.002) =0.87梯梁计算跨度: L0 = L n = 2620 mm梯段板计算跨度: B0 = W-2*b3 = 1800-2*200 =1400 mm梯段板平均厚度: h t = (h+2t/cosα)/2 = (160.00+2*100.00/0.87)/2 = 195.18 mm 2.荷载设计值:(1) 梯段板荷载设计值(取一个踏步宽板带):自重:g kb = R c*h t*b = 25.0*0.20*0.28 = 1.37 kN/m面层:g km = q m*(h+b) = 1.50*(0.16+0.28) = 0.66 kN/m抹灰:g ks = R s*c1*b/cosα = 20.0*0.02*0.28/0.87 = 0.13 kN/m恒荷标准值:P kb = g kb+g km+g ks = 1.37+0.66+0.13 = 2.16 kN/m恒荷控制:P b(G) = 1.35*P kb+γQ*0.7*b*q= 1.35*2.16+1.40*0.7*0.28*3.50 = 3.87 kN/m活荷控制:P b(L) = γG*P kb+γQ*b*q = 1.20*2.16+1.40*0.28*3.50 = 3.96 kN/m荷载设计值:P b = max{ P b(G) , P b(L) } = 3.96 kN/m(2) 斜梯段梯梁荷载设计值:自重放大系数(考虑面层):λb=1.1自重:g kl = λb*R c*b3*h3/cosα = 1.1*25.0*0.20*0.45/0.87 = 2.85 kN/m恒荷标准值:P kl = P kb/b*W/2+g kl+q f = 2.16/0.28*1.80/2+2.85+1.00 = 10.78 kN/m恒荷控制:P l(G) = 1.35*P kl+γQ*0.7*q*W/2= 1.35*10.78+1.40*0.7*3.50*1.80/2 = 17.64 kN/m活荷控制:P l(L) = γG*P kl+γQ*q*W/2 = 1.20*10.78+1.40*3.50*1.80/2 = 17.34 kN/m荷载设计值:P l = max{ P l(G) , P l(L) } = 17.64 kN/m(3) 平台板荷载设计值(取 B = 1m 宽板带):自重:g kb' = R c*h4*B = 25.0*0.10*1.0 = 2.50 kN/m面层:g km' = q m*B = 1.50*1 = 1.50 kN/m抹灰:g ks' = R s*c1*B = 20.0*0.02*1 = 0.40 kN/m恒荷标准值:P kb' = g kb'+g km'+g ks' = 2.50+1.50+0.40 = 4.40 kN/m恒荷控制:P b(G)' = 1.35*P kb'+γQ*0.7*B*q= 1.35*4.40+1.40*0.7*1.0*3.50 = 9.37 kN/m活荷控制:P b(L)' = γG*P kb'+γQ*B*q = 1.20*4.40+1.40*1.0*3.50 = 10.18 kN/m荷载设计值:P b' = max{ P b(G)' , P b(L)' } = 10.18 kN/m(4) 平台段梯梁荷载设计值:自重放大系数(考虑面层):λb=1.1自重:g kl' = λb*R c*b3*h3 = 1.1*25.0*0.20*0.45 = 2.48 kN/m恒荷标准值:P kl' = P kb'/B*W/2+g kl'+q f = 4.40/1.0*1.80/2+2.48+1.00 = 7.44 kN/m恒荷控制:P l(G)' = 1.35*P kl'+γQ*0.7*q*W/2= 1.35*7.44+1.40*0.7*3.50*1.80/2 = 13.12 kN/m活荷控制:P l(L)' = γG*P kl'+γQ*q*W/2 = 1.20*7.44+1.40*3.50*1.80/2 = 13.33 kN/m荷载设计值:P l' = max{ P l(G)' , P l(L)' } = 13.33 kN/m3.梯梁斜截面受剪承载力计算:V max = 22.23 kNV max≤0.7*f t*b3*(h3-a s2)= 0.7*1430.00*0.20*(0.45-0.04)= 82.08 kN按构造配置箍筋。

4.正截面受弯承载力计算:(1) 梯段斜板计算:计算高度:H = (t+h*cosα)/2 = 119.46 mm计算宽度:b0 = b/cosα = 322.49 mmM max = P b*B02/8 = 3.96*1.402/8 = 0.97 kN·m ρ = 0.1011%ρ<ρmin = max{0.002,(0.45*f t/f yv)} = 0.3064% ρ = ρmin = 0.3064%纵筋⑥/⑦计算面积:A s = 91.82 mm2(2) 梯梁计算:M中= 4.55 kN·m ρ = 0.0172%ρ<ρmin = max{0.002,(0.45*f t/f y)} = 0.2000% ρ = ρmin = 0.2000%纵筋①计算面积:A s = 393.00 mm2左支座:M左 = -9.44 kN·m ρ = 0.0788%ρ<ρmin = max{0.002,(0.25*ρ跨中)} = 0.2000% ρ = ρmin = 0.2000%钢筋②计算面积:A s = 180.00 mm2右支座:M右 = -8.53 kN·m ρ = 0.0711%ρ<ρmin = max{0.002,(0.25*ρ跨中)} = 0.2000% ρ = ρmin = 0.2000%钢筋⑤计算面积:A s = 180.00 mm2五、计算结果:1.纵筋①计算结果:计算面积:393.00 mm2采用方案:2 18实配面积:A g = 509mm2实际配筋率:ρ = 0.6207%2.钢筋②计算结果:计算面积:452.39 mm2采用方案:2 12实配面积:A g = 226mm2实际配筋率:ρ = 0.2759%3.箍筋③计算结果:采用方案:2 6@1504.钢筋⑤计算结果:计算面积:180.00 mm2采用方案:2 12实配面积:A g = 226mm25.纵筋⑥/⑦计算结果:计算面积:A s = 91.82 mm2采用方案: 6@80实配面积:A g = 114mm2六、跨中挠度验算:M q -------- 按荷载效应的准永久组合计算的弯矩值取准永久值系数ψq = 0.5梯段梯梁准永久荷载:Q q =P kl+ψq*q*W/2=10.78+0.5*3.50*1.80/2=12.35 kN/m平台梯梁准永久荷载:Q q' =P kl'+ψq*q*W/2=7.44+0.5*3.50*1.80/2=9.01 kN/m(1) 挠度验算参数:M q= 3.15 kN·m(2) 短期刚度B s与长期刚度B:按下列公式计算:ψq = 1.1-0.65*f tk/(ρte*σsq) (混规(7.1.2-2)) σsq = M q/(0.87*h0*A S) (混规(7.1.4-3)) ρte = (A s+A p)/A te(混规(7.1.2-4))B sq = E s*A s*h02/[1.15ψq+0.2+6*αE*ρ/(1+3.5γf')] (混规(7.2.3-1))B = B sq/θ(混规(7.2.2-2))σsq = M q/(0.87*h0*A g) = 3.15*106/(0.87*410*509) = 17.34 N/mmρte = A g/(0.5h3*b3) = 509/(0.5*450*200) = 1.13%ψq = 1.1-0.65*f tk/(ρte*σsq) = 1.1-0.65*2.01/(1.13%*17.34) = 0.20钢筋弹性模量与混凝土模量的比值αE = E s/E c = 7.00受拉翼缘面积与腹板有效面积的比值:γf'= 0纵向受拉钢筋配筋率ρ = 0.6207%B sq = E s*A g*h02/[1.15ψq+0.2+6*αE*ρ/(1+3.5γf'')]= 210*509*0.412/[1.15*0.20+0.2+6*7.00*0.6207%/(1+3.5*0)]= 26012.24 kN·m2荷载长期作用对挠度增大的影响系数θ:当ρ' = 0 时,θ = 2.0Bq = B s/θ= 26012.24/2= 13006.12 kN·m2(3) 跨中挠度:f = 0.11 mm梯梁计算长度L0 = 2.62mf/L0= 1/23728 ≤ 1/200,满足要求。

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