1、 钢筋混凝土楼盖课程设计1.设计资料(1)本设计为一教学楼楼盖(X Y = 30m24m),采用整体式钢筋混凝土现浇板肋梁楼盖。(2)楼面做法:地砖地面(具体做法见),120mm钢筋混凝土现浇板结构层,20mm混合沙浆顶棚抹灰。(3)楼面荷载:均布荷载标准值为2.0 KN/m2。 (4) 材料选用:混凝土强度等级采用C25,梁中架立钢筋、箍筋、板中全部钢筋采用HPB235,其余采用HRB335。 (5) 初步主梁高度取800mm,宽度取300mm,次梁高度取450mm,次梁宽度取200mm,柱子取400mm400mm。 (6) 板的弯矩折减系数为0.8,跨中钢筋在距支座边lx4处截断一半。2.
2、结构布置柱网布置和楼盖梁格布置下图:3.荷载计算恒载标准值:地面构造做法 1.04 KN/m2 120mm钢筋混凝土现浇板 0.1225=3.0 KN/m2 20mm混合沙浆顶棚抹灰 0.0217=0.34 KN/m2 小计:gk=4.38 KN/m2 活载标准值:qk = 2.0 KN/m2恒载分项系数 g = 1.2 (可变荷载效应起控制作用) 活载分项系数 q = 1.4 恒载设计值:g = 4.381.2 = 5.256 KN/m2活载设计值:q = 2.01.4 = 2.8 KN/m2荷载总设计值: p = g + q = 5.256 + 2.8 = 8.056 KN/m2 4. 内
3、力计算及截面设计 以下式中 s取 0.95 , hox = 120 - 20 = 100mm , hoy = 120 - 30 = 90mm,ft =1.27 Nm2fy = 210Nm2 , min = 0.45ftfy = 0.451.27210 = 0.272%0.2%Amin = minbh = 0.272%1000120 = 326.4mm2计算区格 lx = 4000 - 200 = 3800 ly = 6000 - 300 = 5700 n = lylx = 38005700 = 1.5 , 取= 0.45 , = 2.2内力计算 短跨跨中弯矩设计值 mx = (0.8p lx2
4、12)(3n - 1)2(n - 14) + 2n + 32 + 2 = (0.88.056 3.8212)(31.5 - 1)2(1.5 - 14) + 21.52.2 + 30.452 + 20.452.2 = 2.52kNmm 长跨跨中弯矩设计值 my = mx = 0.452.52 = 1.134 kNmm 短跨支座弯矩设计值 mx = mx = mx = 2.22.52 = 5.544 kNmm 长跨支座弯矩设计值 m y= my = my = 2.21.134 = 2.495 kNmm截面设计 短跨跨中 As = mx(fyshox) = 2.52106(2100.95100) =
5、 126mm2 Amin 实配8-150 , 335mm2 长跨跨中 As = my(fyshoy) = 1.134106(2100.9590) = 63mm2 Amin 实配8-150 , 335mm2 短跨支座 As = mx(fyshox) = 5.544106(2100.95100) =278mm2 Amin 实配8-150 , 335mm2 长跨支座 As = m y(fyshoy) = 2.495106(2100.9590) = 139mm2 Amin 实配8-150 , 335mm25. 次梁计算(b=200mm,h=450mm)按塑性内力重分布方法计算,截面尺寸及计算简图见下图
6、:1.荷载 板传来的恒载:4.384.0 = 17.52 kN/m 次梁自重:250.(0.45-0.12) = 1.65 kN/m 次梁抹灰:170.02(0.45-0.12) = 0.22 kN/m 恒载标准值:gk=17.52+1.65+0.22 = 19.39 kN/m 活载标准值:qk = 2.04.0 = 8.0 kN/m2.内力计算: 计算跨度(主梁:300mm800mm) 边跨 l01=ln1=6000-300 = 5700mm 中间跨 l02=ln2=6000-300 = 5700mm.弯矩计算 .边跨 跨中 = 0.078 M = 0.07834.475.72 = 87.3
7、5kN/m B支座 = -0.105 M = -0.10534.475.72 = -117.59kN/m.中间跨 BC跨 跨中 = 0.033 M = 0.03334.475.72 = 36.96kN/m C支座 = -0.079 M = -0.07934.475.72 = -88.47kN/m CD跨 跨中 = 0.046 M = 0.04634.475.72 = 51.52kN/m D支座 = -0.078 M = -0.07834.475.72 = -87.35kN/m.剪力计算: 边支座A = 0.349 VA = 0.39434.475.7 = 77.41kN/m 支座B左 = -0
8、.606 VB左 = 0.39434.475.7 = 77.41kN/m 支座B右 = 0.526 VB右 = 0.52634.475.7 = 103.35kN/m 支座C左 = -0.474 VC左 = -0.47434.475.7 = -93.13kN/m 支座C右 = -0.500 VC右 = 0.50034.475.7 = 98.24kN/m 3.配筋 .正截面受弯承载力计算 次梁跨中截面按T型截面计算,其翼缘宽度为: 边跨 bf = 1/35700 = 1900 b+sn = 4000mm 中间跨 bf = 1900 117.59kNm 故次梁跨中截面均按第一类T型截面计算: b =
9、 200mm , fc = 11.9N/mm2 , fy = 300N/mm2 min = 0.45ft/fy = 0.451.27/300 = 0.0019 0.002 , 取min = 0.2% Amin = minbh = 180mm2.边跨跨中 s = M/(fcbfh02) = 87.35106/(11.919004152) = 0.022 , b = 0.022 As= b fcbfh0/fy = 0.02211.91900415/300 = 688mm2 实配 514 ,769mm2 B支座 s = M/(fcbfh02) = 117.59106/(11.92004152) =
10、0.287 , b = 0.347 As= b fcbfh0/fy = 0.34711.91900415/300 = 1142.4mm2 实配 212+314+218,1196mm2.中间跨 BC跨中 s = M/(fcbfh02) = 26.96106/(11.919004152) = 0.009 , b = 0.009 As= b fcbfh0/fy = 0.00911.91900415/300 = 281.5mm2 实配 214 ,308mm2 C支座 s = M/(fcbfh02) = 88.57106/(11.92004152) = 0.216 , b = 0.246 As= b f
11、cbfh0/fy = 0.24611.9200415/300 = 810mm2 实配 14+212+314 ,841mm2 CD跨中 s = M/(fcbfh02) = 51.52106/(11.919004152) = 0.013 , b = 0.013 As= b fcbfh0/fy = 0.01311.91900415/300 = 406.6mm2 实配 314 ,461mm2.斜截面受剪承载力计算(sv,min)0.241.27/210 = 0.145% b = 200mm , h0 = 450-35 = 415mm , fc = 11.9N/mm2 , ft = 1.27 N/mm2
12、 fyv= 210 N/mm2 , hw/b = (415-120)/200 = 1.475 90.05 kN , 截面合格 0.7ftbh0 = 0.71.27200415 = 73.79 kN支座A V = 77.41 kN ,实配 6-130 Vcs = 73.79+47.43 = 121.27 kN支座B VB左 = 119.07 kN ,实配 6-130 Vcs = 73.79+47.43 = 121.27 kN VB右 = 103.35 kN ,实配 6-190 Vcs = 73.79+32.5 = 106.29 kN支座C VC左 = 93.13 kN ,实配 6-190 Vcs
13、 = 73.79+32.5 = 106.29 kN VC右 = 98.24kN ,实配 6-190 Vcs = 73.79+32.5 = 106.29 kNsv = (nAsv1)/(bs) = 228.3/(200190) = 0149% sv,minS 5 故主梁视为铰支在柱子顶上的连续梁,截面尺寸及计算简图如下:1.荷载 由次梁传来的恒载 19.396 = 116.34 kN 主梁自重 250.3(0.8-0.12)4 = 20.4 kN 主梁抹灰 170.02(0.8-0.12) = 0.92 kN 恒载标准值Gk = 137.66kN 活载标准值 Qk = 68 = 48kN 恒载设
14、计值 G = 1.2137.66 = 165.19kN 活载标准值 Q = 1.448 = 67.2 kN2. 计算跨度 本设计为等跨框架结构,边跨、中间跨的净跨与计算跨度差值均小于10%,故按等跨连续梁计算,由教材附表12-3查内力系数k进行计算。 项次 荷载简图 弯矩(kNm) 剪力(kN)边跨跨中B支座中间跨跨中A支座B支座(左)B支座(右) k/M1 k/MB k/M2 k/VA k/VB左 k/VB右 0.175-0.1500.1000.350-0.650.500231.27-198.23132.1557.82-107.3782.60 0.213-0.0750.425-0.57501
15、14.51-40.3228.56-38.640 -0.0750.175-0.075-0.0750.500-40.3294.08-5.04-5.0433.60 0.163-0.1750.1370.325-06750.62587.63-94.0873.6521.84-45.3642.00 0.2000.0100.400-0.6000.125107.525.3826.88-40.328.40内力不利组合 + 345.78-238.55132.1586.38-146.0182.60 + 231.27-238.55226.2352.78-12.41116.20 + 318.90-292.31205.80
16、79.66-152.73124.60 + 338.79-192.85132.1584.70-147.6991.003. 内力包络图4.配筋 正截面承载力计算 主梁跨中截面按T型截面计算,其翼缘宽度为 bf = 1/28000= 4000 345.78kNm 主梁跨中截面按第一类T型截面计算。主梁支座截面按矩形截面计算 b = 300mm , h0 =680mmB支座边M = 283.55 - 0.2124.60 = 213.63 kNmfc = 11.9N/mm2 , fy = 300N/mm2.边跨跨中 s = M/(fcbfh02) = 345.78106/(11.940007602) =
17、 0.0126, b = 0.0126 As= b fcbfh0/fy = 0.012611.94000760/300 = 1519.4mm2 实配 418+218,1527mm2 B支座 s = M/(fcbfh02) = 238.55106/(11.93006802) = 0.146 , b = 0.156 As= b fcbfh0/fy = 0.15611.9300680/300 = 1262.4mm2 实配 418+18,1272mm2中间跨跨中 s = M/(fcbfh02) = 226.23106/(11.940007602) = 0.008, b = 0.008 As= b fc
18、bfh0/fy = 0.00811.94000760/300 = 946.7mm2 实配 218+218,1017mm2.斜截面受剪承载力计算: b=300mm , h0 =680mm , fc = 11.9N/mm2 , ft = 1.27 N/mm2 , fyv= 210 N/mm2 0.2511.9300680 = 606.9 kN V 截面合适0.7ftbh0 = 0.71.27300680 = 181.36 kNA支座 V = 86.38 kN , 配箍8-230 , Vcs= 181.36 + 78.07 = 259.43kN VB支座(左) V = 179.61 kN , 配箍8
19、-230 , Vcs= 181.36 + 78.07 = 259.43kN VB支座(右) V = 152.73 kN , 配箍8-230 , Vcs= 181.36 + 78.07 = 259.43kN Vsv = (nAsv1)/(bs) = 250.3/(300230) = 0.146% sv,min 5. 附加箍筋计算次梁传来的集中力F=1.2116.34+1.448 = 206.81kN用8双肢箍筋,Asv = 50.3mm2 , fyv= 210 N/mm2m = F/(fyvAsv) = 206.81106/(21050.3) = 9.79 , 取10个6. 抵抗弯矩图及钢筋布置
20、.弯起钢筋的起弯点,距离该钢筋的强度充分利用点为450mmh0/2.钢筋切断位置(B支座处) 由于切断处V全部大于0.7ftbh0 ,故应从该钢筋强度的充分利用点外伸1.2la+h0 ,及以该钢筋的理论断点外伸不小于h0,且不小于20d.跨中正弯矩钢筋伸入支座长度las应12d , 对18钢筋 1218 = 216 ,取220mm.支座B,构造要求负弯矩钢筋面积1/4跨中钢筋,618 As=509 1/41257 = 382mm2,要求伸入支座边la=33d , 18钢筋:la=3318 = 594 ,伸入梁端340,再下弯400mm详见施工图课程设计课程名称: 学 院: 专 业: 姓 名: 学 号: 年 级: 任课教师: 年 月 日