人防楼梯计算

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人防楼梯计算

1 板式楼梯: TB-1

1.1 基本资料

1.1.1 工程名称: 工程一

1.1.2 楼梯类型: 板式 A 型 ( ╱ ),支座条件: 两端弹性

1.1.3 踏步段水平净长 Lsn = 2080mm,梯板净跨度 Ln = Lsn = 2080mm,

梯板净宽度 B = 1290mm

1.1.4 低端支座宽度 dl = 350mm,高端支座宽度 dh = 350mm

计算跨度 L0 = Min{Ln + (dl + dh) / 2, 1.05Ln} = Min{2430, 2184} = 2184mm

1.1.5 梯板厚度 h1 = 200mm

1.1.6 踏步段总高度 Hs = 1500mm,楼梯踏步级数 n = 9

1.1.7 线性恒荷标准值 Pk = 1kN/m; 均布活荷标准值 qk = 3.5kN/m,ψc = 0.7,

ψq = 0.4

1.1.8 面层厚度 c1 = 25mm,面层容重 γc2 = 20kN/m; 顶棚厚度 c2 = 20mm,

顶棚容重 γc2 = 18kN/m; 楼梯自重容重 γb = 25kN/m

1.1.9 爆炸动荷载作用下的等效静荷载标准值

板面均布荷载: qe1 = 60kN/m

板底均布荷载: qe2 = -30kN/m

1.1.10 混凝土强度等级为 C30, fc = 14.331N/mm, ft = 1.433N/mm,

ftk = 2.006N/mm, Ec = 29791N/mm

1.1.11 钢筋抗拉强度设计值 fy = 360N/mm, Es = 200000N/mm;

纵筋的混凝土保护层厚度 c = 15mm

1.1.12 考虑爆炸动荷载组合时,材料动力强度设计值: fcd = 21.497N/mm,

ftd = 2.149N/mm, fyd = 432N/mm; 允许延性比 [β] = 3

1.2 楼梯几何参数

1.2.1 踏步高度 hs = Hs / n = 1500/9 = 166.7mm

踏步宽度 bs = Lsn / (n - 1) = 2080/(9-1) = 260mm

踏步段斜板的倾角 α = ArcTan(hs / bs) = ArcTan(166.7/260) = 32.7°

踏步段斜板的长度 Lx = Lsn / Cosα = 2080/Cos32.7° = 2471mm

1.2.2 踏步段梯板厚的垂直高度 h1' = h1 / Cosα = 200/Cos32.7° = 238mm

踏步段梯板平均厚度 T = (hs + 2h1') / 2 = (167+2*238)/2 = 321mm

1.2.3 梯板有效高度 h10 = h1 - as = 200-20 = 180mm

1.3 均布永久荷载标准值

1.3.1 梯板上的线载换算为均布恒荷 gk1 = Pk / B = 1/1.29 = 0.78kN/m

1.3.2 梯板自重 gk2 = γb·T = 25*0.321 = 8.02kN/m

1.3.3 踏步段梯板面层自重

gk3 = γc1·c1·(n - 1)(hs + bs) / Ln = 20*0.025*(9-1)*(0.167+0.26)/2.08 = 0.82kN/m

1.3.4 梯板顶棚自重 gk4' = γc2·c2 = 18*0.02 = 0.36kN/m

gk4 = gk4'·Lx / Ln = 0.36*2.471/2.08 = 0.43kN/m

1.3.5 均布荷载标准值汇总 gk = gk1 + gk2 + gk3 + gk4 = 10.05kN/m

1.4 均布荷载的基本组合值

1.4.1 板面爆炸动荷载 qe1 作用下

Qe1 = 1.2gk + qe1·(Lx / Lsn)2 = 1.2*10.05+60*(2.471/2.08)2 = 96.71kN/m

1.4.2 板底爆炸动荷载 qe2 作用下

Qe2 = 1.0gk + qe2·(Lx / Lsn)2 = 1.0*10.05-30*(2.471/2.08)2 = -32.28kN/m

1.4.3 平时荷载作用下

由可变荷载控制的 Q(L) = γG·gk + γQ·qk = 1.2*10.05+1.4*3.5 = 16.95kN/m

由永久荷载控制的 Q(D) = γG1·gk + γQ·ψc· qk = 1.35*10.05+1.4*0.7*3.5

= 16.99kN/m

最不利的荷载基本组合值 Q = Max{Q(L), Q(D)} = Max{16.95, 16.99} = 16.99kN/m

1.5 梯板的支座反力

1.5.1 板面爆炸动荷载 qe1 作用下

最不利的均布反力基本组合值 R = 100.58kN/m

1.5.2 板底爆炸动荷载 qe2 作用下

最不利的均布反力基本组合值 R = -33.57kN/m

1.5.3 平时荷载作用下

永久荷载作用下均布反力标准值 Rk(D) = 10.45kN/m

可变荷载作用下均布反力标准值 Rk(L) = 3.64kN/m

最不利的均布反力基本组合值 R = 17.67kN/m

1.6 梯板斜截面受剪承载力计算

1.6.1 板面爆炸动荷载 qe1 作用下

V = 0.5·Q·Ln·Cosα = 0.5*96.71*2.08*Cos32.7° = 84.7kN

当跨高比 Ln/h0 = 11.56 > 8 时,取 ψl = 1 - (l/h0 - 8) / 15 = 0.76

R = 0.7·ψl·0.8ftd·b·h0 = 0.7*0.76*0.8*2149*1*0.18

= 165.3kN ≥ V = 84.7kN,满足要求。

1.6.2 板底爆炸动荷载 qe2 作用下

V = 0.5·Q·Ln·Cosα = 0.5*32.28*2.08*Cos32.7° = 28.3kN

R = 0.7·ψl·0.8ftd·b·h0 = 0.7*0.76*0.8*2149*1*0.18

= 165.3kN ≥ V = 28.3kN,满足要求。

1.6.3 平时荷载作用下

V = 0.5·Q·Ln·Cosα = 0.5*16.99*2.08*Cos32.7° = 14.9kN

R = 0.7·βh·ft·b·h0 = 0.7*1*1433*1*0.18 = 180.5kN ≥ V = 14.9kN,满足要求。

1.7 正截面受弯承载力计算

1.7.1 板面爆炸动荷载 qe1 作用下 1.7.1.1 跨中板底 M = Q·L02 / 10 = 96.71*2.1842/10 = 46.13kN·m

As = 614mm,as = 20mm,ξ = 0.069,ρ = 0.34%;

实配纵筋: 10@110 (As = 714)

1.7.1.2 支座板面 M = -Q·L02 / 20 = -96.71*2.1842/20 = -23.06kN·m

As = 300mm,as = 19mm,ξ = 0.033,ρ = 0.17%; ρmin = 0.25%,

As,min = 500mm; 实配纵筋: 8@100 (As = 503)

1.7.2 板底爆炸动荷载 qe2 作用下

1.7.2.1 跨中板面 M = -Q·L02 / 10 = -32.28*2.1842/10 = -15.40kN·m

As = 200mm,as = 20mm,ξ = 0.022,ρ = 0.11%; ρmin = 0.25%,

As,min = 500mm; 实配纵筋: 10@140 (As = 561)

1.7.2.2 支座板底 M = Q·L02 / 20 = 32.28*2.1842/20 = 7.70kN·m

As = 100mm,as = 20mm,ξ = 0.011,ρ = 0.06%; ρmin = 0.25%,

As,min = 500mm; 实配纵筋: 10@110 (As = 714)

1.7.3 平时荷载作用下

1.7.3.1 跨中板底 M = Q·L02 / 10 = 16.99*2.1842/10 = 8.10kN·m

As = 126mm,as = 20mm,ξ = 0.018,ρ = 0.07%; ρmin = 0.20%,

As,min = 400mm; 实配纵筋: 10@110 (As = 714); 最大裂缝宽度 ωmax = 0.014mm

1.7.3.2 支座板面 M = -Q·L02 / 20 = -16.99*2.1842/20 = -4.05kN·m

As = 63mm,as = 20mm,ξ = 0.009,ρ = 0.03%; ρmin = 0.20%,

As,min = 400mm; 实配纵筋: 10@140 (As = 561); 最大裂缝宽度 ωmax = 0.009mm

1.8 跨中挠度验算

跨中挠度 f = 0.5mm f/L0 = 1/4,799

1.9 板式楼梯平面整体表示方法的注写内容

AT1, h = 200 166.7X9 = 1500 板面:10@140, 板底:10@110

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【MorGain 结构快速设计程序 V2010.05.1930.1925】 Date:2011-05-12 15:36:46

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