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 C 型 ( ╱ ̄),支座条件: 低端固定高端铰支 1.1.3 踏步段水平净长 Lsn = 4420mm,高端平板净长 Lhn = 1280mm, 梯板净跨度 Ln = Lsn + Lhn = 4420+1280 = 5700mm,梯板净宽度 B = 1200mm
1.1.4 低端支座宽度 dl = 200mm,高端支座宽度 dh = 200mm
计算跨度 L0 = Min{Ln + (dl + dh ) / 2, 1.05Ln } = Min{5900, 5985} = 5900mm
1.1.5 梯板厚度 h1 = 150mm
1.1.6 踏步段总高度 Hs = 3000mm,楼梯踏步级数 n = 18
2
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
3
1.1.8 面层厚度 c1 = 30mm,面层容重 γc2 = 25kN/m; 顶棚厚度 c2 = 20mm,
33
顶棚容重 γc2 = 25kN/m; 楼梯自重容重 γb = 25kN/m
22
1.1.9 混凝土强度等级为 C30, fc = 14.331N/mm, ft = 1.433N/mm, ftk =
2
2.006N/mm,
2
Ec = 29791N/mm
22
1.1.10 钢筋抗拉强度设计值 fy = 270N/mm, Es = 210000N/mm;
22
当纵筋直径不小于 12mm 时,取 fy = 360N/mm、E s = 200000N/mm; 纵筋的混凝土保护层厚度 c = 20mm
1.2 楼梯几何参数
1.2.1 踏步高度 hs = Hs / n = 3000/18 = 166.7mm
踏步宽度 bs = Lsn / (n - 1) = 4420/(18-1) = 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 = 4420/Cos32.7° = 5250mm 1.2.2 踏步段梯板厚的垂直高度 h1' = h1 / Cosα = 150/Cos32.7° = 178.2mm
踏步段梯板平均厚度 T = (hs + 2h 1') / 2 = (166.7+2*178.2)/2 = 261.5mm 1.2.3 梯板有效高度 h10 = h1 - as = 150-25 = 125mm
1.3 均布永久荷载标准值
2
1.3.1 梯板上的线载换算为均布恒荷 gk1 = Pk / B = 1/1.2 = 0.83kN/m
2
1.3.2 踏步段梯板自重 gk2' = γb ·T = 25*0.2615 = 6.54kN/m
2
gk2 = gk2' ·L sn / Ln = 6.54*4.42/5.7 = 5.07kN/m
2
1.3.3 高端平板自重 gk3' = γb ·h 1 = 25*0.15 = 3.75kN/m
2
gk3 = gk3' ·L hn / Ln = 3.75*1.28/5.7 = 0.84kN/m 1.3.4 踏步段梯板面层自重
gk4' = γc1·c 1·(n - 1)(hs + bs ) / Lsn = 25*0.03*(18-1)*(0.1667+0.26)/4.42
2
= 1.23kN/m
2
gk4 = gk4' ·L sn / Ln = 1.23*4.42/5.7 = 0.95kN/m
1.3.5 高端平板面层自重 gk5' = γc1·c 1 = 25*0.03 = 0.75kN/m
2
gk5 = gk5' ·L hn / Ln = 0.75*1.28/5.7 = 0.17kN/m
2
1.3.6 梯板顶棚自重 gk6' = γc2·c 2 = 25*0.02 = 0.50kN/m
2
gk6 = gk6' ·(Ln + Lx - Lsn ) / Ln = 0.5*(5.7+5.25-4.42)/5.7 = 0.57kN/m
2
1.3.7 均布荷载标准值汇总 gk = gk1 + gk2 + gk3 + gk4 + gk5 + gk6 = 8.44kN/m
1.4 均布荷载的基本组合值
由可变荷载控制的 Q(L) = γG ·g k + γQ ·q k = 1.2*8.44+1.4*3.5 =
2
15.03kN/m
由永久荷载控制的 Q(D) = γG1·g k + γQ ·ψc · qk = 1.35*8.44+1.4*0.7*3.5
2
= 14.82kN/m
最不利的荷载基本组合值 Q = Max{Q(L), Q(D)} = Max{15.03, 14.82} =
2
15.03kN/m
1.5 梯板的支座反力
低端支座永久荷载作用下均布反力标准值 Rk (D) = 30.07kN/m 低端支座可变荷载作用下均布反力标准值 Rk (L) = 12.47kN/m 低端支座最不利的均布反力基本组合值 R = 53.54kN/m
高端支座永久荷载作用下均布反力标准值 Rk (D) = 18.04kN/m 高端支座可变荷载作用下均布反力标准值 Rk (L) = 7.48kN/m 高端支座最不利的均布反力基本组合值 R = 32.12kN/m
1.6 梯板斜截面受剪承载力计算 V ≤ 0.7·βh ·f t ·b·h 0
V = 5/8·Q ·L n ·Cos α = 0.625*15.03*5.7*Cos32.7° = 45.1kN
R = 0.7·βh ·f t ·b·h 0 = 0.7*1*1433*1*0.125 = 125.4kN ≥ V = 45.1kN,满足要求。
1.7 正截面受弯承载力计算
22
1.7.1 跨中 Mmax = 9/128·Q ·L 0 = 0.07031*15.03*5.9 = 36.78kN·m
2
As = 907mm,a s = 26mm,ξ = 0.184,ρ = 0.73%;
实配纵筋: (Ⅱ) 12@100 (A s = 1131); 最大裂缝宽度 ωmax = 0.126mm
22
1.7.2 低端支座 Mmin = -1/8·Q ·L 0 = -0.125*15.03*5.9 = -65.39kN·m
2
As = 1836mm,a s = 28mm,ξ = 0.378,ρ = 1.50%;
实配纵筋: (Ⅱ) 16@100 (A s = 2011); 最大裂缝宽度 ωmax = 0.140mm
2
1.7.3 铰支端支座构造负筋: ρmin = 0.24%,A s ,min = 358mm; 实配纵筋: φ10@200 (A s = 393)
1.8 跨中挠度验算 1.8.1 挠度验算参数
按荷载效应的准永久组合计算的弯矩值 Mq = 24.09kN·m
1.8.2 荷载准永久组合作用下钢筋混凝土受弯构件的短期刚度 Bs 1.8.2.1 裂缝间纵向受拉钢筋应变不均匀系数 ψ
σsq = Mq / (0.87h0·A s ) (混凝土规范式 7.1.4-3)
2
σsq = 24085677/(0.87*124*1131) = 197N/mm
2
矩形截面,A te = 0.5·b ·h = 0.5*1000*150 = 75000mm ρte = As / Ate (混凝土规范式 7.1.2-4) ρte = 1131/75000 = 0.01508
ψ = 1.1 - 0.65ftk / (ρte ·σs ) (混凝土规范式 7.1.2-2) ψ = 1.1-0.65*2.006/(0.01508*197) = 0.6620 1.8.2.2 钢筋弹性模量与混凝土模量的比值: αE = Es / E c = 200000/29791 = 6.713
1.8.2.3 受压翼缘面积与腹板有效面积的比值 γf ' 矩形截面,γf ' = 0
1.8.2.4 纵向受拉钢筋配筋率 ρ = As / (b·h 0) = 1131/(1000*124) = 0.00912
1.8.2.5 钢筋混凝土受弯构件的短期刚度 Bs 按混凝土规范式 7.2.3-1 计算:
2
Bs = Es ·A s ·h 0 / [1.15ψ + 0.2 + 6·αE ·ρ / (1 + 3.5γf ')]
2
= 200000*1131*124/[1.15*0.662+0.2+6*6.713*0.00912/(1+3.5*0)] =
2
2617.66kN ·m
1.8.3 考虑荷载长期效应组合对挠度影响增大影响系数 θ 按混凝土规范第 7.2.5 条,当 ρ' = 0 时,取 θ = 2.0
1.8.4 受弯构件的长期刚度 B 按混凝土规范式 7.2.2-2 计算:
2
B = Bs / θ = 2617.66/2 = 1308.83kN·m 1.8.5 跨中挠度 f
挠度验算时考虑踏步刚度,踏步段等效高度 heq = 162.7mm,挠度折减系数 η = 0.8097
44
f = 0.8097·2.08/384·Q q ·L 0 / B = 0.004385*9.84*5.9/1308.83*1000 = 40.0mm
f/L0 = 40/5900 = 1/148
1.9 板式楼梯平面整体表示方法的注写内容 CT1, h = 150 166.7X18 = 3000 低端板面:(Ⅱ) 16@100, 板底:(Ⅱ) 12@100
2
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 C 型 ( ╱ ̄),支座条件: 低端固定高端铰支 1.1.3 踏步段水平净长 Lsn = 4420mm,高端平板净长 Lhn = 1280mm, 梯板净跨度 Ln = Lsn + Lhn = 4420+1280 = 5700mm,梯板净宽度 B = 1200mm
1.1.4 低端支座宽度 dl = 200mm,高端支座宽度 dh = 200mm
计算跨度 L0 = Min{Ln + (dl + dh ) / 2, 1.05Ln } = Min{5900, 5985} = 5900mm
1.1.5 梯板厚度 h1 = 150mm
1.1.6 踏步段总高度 Hs = 3000mm,楼梯踏步级数 n = 18
2
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
3
1.1.8 面层厚度 c1 = 30mm,面层容重 γc2 = 25kN/m; 顶棚厚度 c2 = 20mm,
33
顶棚容重 γc2 = 25kN/m; 楼梯自重容重 γb = 25kN/m
22
1.1.9 混凝土强度等级为 C30, fc = 14.331N/mm, ft = 1.433N/mm, ftk =
2
2.006N/mm,
2
Ec = 29791N/mm
22
1.1.10 钢筋抗拉强度设计值 fy = 270N/mm, Es = 210000N/mm;
22
当纵筋直径不小于 12mm 时,取 fy = 360N/mm、E s = 200000N/mm; 纵筋的混凝土保护层厚度 c = 20mm
1.2 楼梯几何参数
1.2.1 踏步高度 hs = Hs / n = 3000/18 = 166.7mm
踏步宽度 bs = Lsn / (n - 1) = 4420/(18-1) = 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 = 4420/Cos32.7° = 5250mm 1.2.2 踏步段梯板厚的垂直高度 h1' = h1 / Cosα = 150/Cos32.7° = 178.2mm
踏步段梯板平均厚度 T = (hs + 2h 1') / 2 = (166.7+2*178.2)/2 = 261.5mm 1.2.3 梯板有效高度 h10 = h1 - as = 150-25 = 125mm
1.3 均布永久荷载标准值
2
1.3.1 梯板上的线载换算为均布恒荷 gk1 = Pk / B = 1/1.2 = 0.83kN/m
2
1.3.2 踏步段梯板自重 gk2' = γb ·T = 25*0.2615 = 6.54kN/m
2
gk2 = gk2' ·L sn / Ln = 6.54*4.42/5.7 = 5.07kN/m
2
1.3.3 高端平板自重 gk3' = γb ·h 1 = 25*0.15 = 3.75kN/m
2
gk3 = gk3' ·L hn / Ln = 3.75*1.28/5.7 = 0.84kN/m 1.3.4 踏步段梯板面层自重
gk4' = γc1·c 1·(n - 1)(hs + bs ) / Lsn = 25*0.03*(18-1)*(0.1667+0.26)/4.42
2
= 1.23kN/m
2
gk4 = gk4' ·L sn / Ln = 1.23*4.42/5.7 = 0.95kN/m
1.3.5 高端平板面层自重 gk5' = γc1·c 1 = 25*0.03 = 0.75kN/m
2
gk5 = gk5' ·L hn / Ln = 0.75*1.28/5.7 = 0.17kN/m
2
1.3.6 梯板顶棚自重 gk6' = γc2·c 2 = 25*0.02 = 0.50kN/m
2
gk6 = gk6' ·(Ln + Lx - Lsn ) / Ln = 0.5*(5.7+5.25-4.42)/5.7 = 0.57kN/m
2
1.3.7 均布荷载标准值汇总 gk = gk1 + gk2 + gk3 + gk4 + gk5 + gk6 = 8.44kN/m
1.4 均布荷载的基本组合值
由可变荷载控制的 Q(L) = γG ·g k + γQ ·q k = 1.2*8.44+1.4*3.5 =
2
15.03kN/m
由永久荷载控制的 Q(D) = γG1·g k + γQ ·ψc · qk = 1.35*8.44+1.4*0.7*3.5
2
= 14.82kN/m
最不利的荷载基本组合值 Q = Max{Q(L), Q(D)} = Max{15.03, 14.82} =
2
15.03kN/m
1.5 梯板的支座反力
低端支座永久荷载作用下均布反力标准值 Rk (D) = 30.07kN/m 低端支座可变荷载作用下均布反力标准值 Rk (L) = 12.47kN/m 低端支座最不利的均布反力基本组合值 R = 53.54kN/m
高端支座永久荷载作用下均布反力标准值 Rk (D) = 18.04kN/m 高端支座可变荷载作用下均布反力标准值 Rk (L) = 7.48kN/m 高端支座最不利的均布反力基本组合值 R = 32.12kN/m
1.6 梯板斜截面受剪承载力计算 V ≤ 0.7·βh ·f t ·b·h 0
V = 5/8·Q ·L n ·Cos α = 0.625*15.03*5.7*Cos32.7° = 45.1kN
R = 0.7·βh ·f t ·b·h 0 = 0.7*1*1433*1*0.125 = 125.4kN ≥ V = 45.1kN,满足要求。
1.7 正截面受弯承载力计算
22
1.7.1 跨中 Mmax = 9/128·Q ·L 0 = 0.07031*15.03*5.9 = 36.78kN·m
2
As = 907mm,a s = 26mm,ξ = 0.184,ρ = 0.73%;
实配纵筋: (Ⅱ) 12@100 (A s = 1131); 最大裂缝宽度 ωmax = 0.126mm
22
1.7.2 低端支座 Mmin = -1/8·Q ·L 0 = -0.125*15.03*5.9 = -65.39kN·m
2
As = 1836mm,a s = 28mm,ξ = 0.378,ρ = 1.50%;
实配纵筋: (Ⅱ) 16@100 (A s = 2011); 最大裂缝宽度 ωmax = 0.140mm
2
1.7.3 铰支端支座构造负筋: ρmin = 0.24%,A s ,min = 358mm; 实配纵筋: φ10@200 (A s = 393)
1.8 跨中挠度验算 1.8.1 挠度验算参数
按荷载效应的准永久组合计算的弯矩值 Mq = 24.09kN·m
1.8.2 荷载准永久组合作用下钢筋混凝土受弯构件的短期刚度 Bs 1.8.2.1 裂缝间纵向受拉钢筋应变不均匀系数 ψ
σsq = Mq / (0.87h0·A s ) (混凝土规范式 7.1.4-3)
2
σsq = 24085677/(0.87*124*1131) = 197N/mm
2
矩形截面,A te = 0.5·b ·h = 0.5*1000*150 = 75000mm ρte = As / Ate (混凝土规范式 7.1.2-4) ρte = 1131/75000 = 0.01508
ψ = 1.1 - 0.65ftk / (ρte ·σs ) (混凝土规范式 7.1.2-2) ψ = 1.1-0.65*2.006/(0.01508*197) = 0.6620 1.8.2.2 钢筋弹性模量与混凝土模量的比值: αE = Es / E c = 200000/29791 = 6.713
1.8.2.3 受压翼缘面积与腹板有效面积的比值 γf ' 矩形截面,γf ' = 0
1.8.2.4 纵向受拉钢筋配筋率 ρ = As / (b·h 0) = 1131/(1000*124) = 0.00912
1.8.2.5 钢筋混凝土受弯构件的短期刚度 Bs 按混凝土规范式 7.2.3-1 计算:
2
Bs = Es ·A s ·h 0 / [1.15ψ + 0.2 + 6·αE ·ρ / (1 + 3.5γf ')]
2
= 200000*1131*124/[1.15*0.662+0.2+6*6.713*0.00912/(1+3.5*0)] =
2
2617.66kN ·m
1.8.3 考虑荷载长期效应组合对挠度影响增大影响系数 θ 按混凝土规范第 7.2.5 条,当 ρ' = 0 时,取 θ = 2.0
1.8.4 受弯构件的长期刚度 B 按混凝土规范式 7.2.2-2 计算:
2
B = Bs / θ = 2617.66/2 = 1308.83kN·m 1.8.5 跨中挠度 f
挠度验算时考虑踏步刚度,踏步段等效高度 heq = 162.7mm,挠度折减系数 η = 0.8097
44
f = 0.8097·2.08/384·Q q ·L 0 / B = 0.004385*9.84*5.9/1308.83*1000 = 40.0mm
f/L0 = 40/5900 = 1/148
1.9 板式楼梯平面整体表示方法的注写内容 CT1, h = 150 166.7X18 = 3000 低端板面:(Ⅱ) 16@100, 板底:(Ⅱ) 12@100
2