已知：車(chē)間倉(cāng)庫(kù)的樓面梁格布置如圖17所示，軸線(xiàn)尺寸為30m19.8m, 樓面面層為20mm厚水泥砂漿抹面，梁板的天花抹灰為15mm厚混合砂漿，樓面活荷載選用7.0kN/m2 ,混凝土采用C20，梁中受力鋼筋采用HRB335, 其他鋼筋一律采用HPB235，板厚80mm，次梁截面為bh=200mm450mm，主梁截面為bh=300mm700mm，柱截面為bh=400mm400mm。樓板周邊支承在磚墻上，試設(shè)計(jì)此樓蓋。 一、板的計(jì)算（按考慮塑性?xún)?nèi)力重分布的方法計(jì)算）1、荷載計(jì)算20mm厚水泥砂漿面層 200.02=0.400kN/m2 80mm厚現(xiàn)澆鋼筋混凝土板 25 0.08=2.000kN/m215mm厚石灰砂漿抹底 170.015=0.225kN/m2恒載標(biāo)準(zhǔn)值: =0.4+2.0+0.225=2.655 9.420kN/m2 活載標(biāo)準(zhǔn)值: =7.000 kN/m2經(jīng)試算, 永久荷載效應(yīng)控制的組合為最不利組合,因此取荷載設(shè)計(jì)值=1.352.655+1.01.37.000=12.684 kN/m2 2、計(jì)算簡(jiǎn)圖 取1m寬板帶作為計(jì)算單元, 各跨的計(jì)算跨度為:中間跨: =2200-200=2000mm邊跨: =2200100120+1200/2=2040mm取2020mm平均跨度: =(2020+2000)/2=2010mm3、內(nèi)力計(jì)算:因跨度差: (2020-2000)/2000=1%<10%故可按等跨連續(xù)板計(jì)算內(nèi)力各截面的彎距計(jì)算見(jiàn)表5截面邊跨中第一內(nèi)支座中間跨度中間支座彎距系數(shù)+1/11-1/11+1/16-1/16(kNm)1/1112.72.0224.71-1/1112.72.0224.711/1612.72.023.18-1/1612.72.023.18板彎距計(jì)算 表5 4、截面強(qiáng)度計(jì)算=210N/mm2 , =9.6 N/mm2, =1.0, = 8020=60mm正截面強(qiáng)度計(jì)算見(jiàn)表6正截面強(qiáng)度計(jì)算 表6 截面邊跨中B支座中間跨中中間支座在平面圖上的位置M(kNm)4.714.713.180.83.183.18-0.83.180.1360.1360.0920.0730.0920.0730.9270.9270.9520.9620.9520.962(mm2)403.25403.25265.11209.55265.11209.55選用鋼筋812581256/812561256/81256125實(shí)際配筋面積402402314226314226根據(jù)計(jì)算結(jié)果及板的構(gòu)造要求, 畫(huà)出配筋圖如圖20所示二、次梁的計(jì)算（按考慮塑性?xún)?nèi)力重分布的方法計(jì)算）1、荷載計(jì)算板傳來(lái)的恒載： 2.6552.2=5.841 kN/m次梁自重： 250.2(0.450.08) =1.850 kN/m次梁粉刷抹灰： 170.01510.450.0872=0.189 kN/m恒載標(biāo)準(zhǔn)值: =5.841+1.850+0.189=7.880 kN/m 活載標(biāo)準(zhǔn)值: =7.0002.2=15.400 kN/m經(jīng)試算, 永久荷載效應(yīng)控制的組合為最不利組合, 因此取荷載設(shè)計(jì)值=1.357.880+1.01.315.400=30.7 kN/m22、計(jì)算簡(jiǎn)圖各跨的計(jì)算跨度為:中間跨: =n =6000300=5700mm邊跨: =6000150120+250/2=5855mm1.025=5873.25mm, 取小值5855mm平均跨度: =(5855+5700)/2=5777.5mm跨度差: (58511-5700)/5700=2.7%<10%次梁的計(jì)算簡(jiǎn)圖見(jiàn)圖21。3、內(nèi)力計(jì)算:見(jiàn)表7、表8次梁的彎距計(jì)算 表7 截面邊跨中第一內(nèi)支座中間跨度中間支座彎矩系數(shù)+1/11-1/11+1/16-1/16(kNm)1/1130.75.8552=95.7-1/1130.75.7782=-93.21/1630.75.702=62.3-1/1630.75.702=-62.3次梁的剪力計(jì)算 表8 截面A支座B支座左B支座右c支座剪力系數(shù)0.450.550.550.55(kN)0.4530.75.73=79.160.5530.75.73=96.70.5530.75.70=96.30.5530.75.70=96.34、正截面強(qiáng)度計(jì)算（1）次梁跨中截面按T形截面計(jì)算邊跨：=5.855/3=1.95m =0.2+1.98=2.18m 取=1.95m中間跨：=5.7/3=1.90m =0.2+2.0=2.2m 取=1.90m支座截面按矩形截面計(jì)算(2) 判斷截面類(lèi)型h0h3545035415mm， fy300 N/mm2=1.09.6195080(4111-80/2) =561.6 kNm95.7 kNm(62.3 kNm) 屬于第一類(lèi)T形截面次梁正截面強(qiáng)度計(jì)算見(jiàn)表9次梁正截面強(qiáng)度計(jì)算 表9 截面邊跨中B支座中間跨中中間支座M(kNm)95.7-93.262.3-62.3或(mm)195020019002000.02970.2820.01980.1880.9850.8300.990.895(mm2)780.4901.9505.5559.1選用鋼筋216(彎)216(直)214(直)316(彎)116(彎)216(直)212(直)216(彎)實(shí)際配筋面積 (mm2)8049116036285、斜截面強(qiáng)度計(jì)算：次梁斜截面強(qiáng)度計(jì)算見(jiàn)表10次梁斜截面強(qiáng)度計(jì)算 表10 截面A支座B支座左B支座右C支座(kN)79.1696.796.396.3(kN)0.251.09.6200415=199.2kN>V 截面滿(mǎn)足要求(kN)0.71.1200415=63.91kN<V 按計(jì)算配箍箍筋直徑和肢數(shù)6 雙肢(mm2)228.3=56.6228.3=56.6228.3=56.6228.3=56.6(mm)404.3188.1190.4190.4實(shí)配間距(mm)180180180180計(jì)算結(jié)果及次梁的構(gòu)造要求，繪次梁配筋圖, 見(jiàn)圖22。三、主梁的計(jì)算（按彈性理論計(jì)算）1、荷載計(jì)算: 次梁傳來(lái)的恒載： 7.886.0=47.28kN/m2主梁自重： 250.3（0.70.08）2.2=10.23kN梁側(cè)抹灰： 170.015（0.70.08）22.2=0. 696 kN恒載標(biāo)準(zhǔn)值: =47.28+10.23+0.696=58.206 kN 活載標(biāo)準(zhǔn)值: =15.46=92.400 kN恒載設(shè)計(jì)值: 1.35=1.3558.206=78.58 kN活載設(shè)計(jì)值: 1.3=1.392.40=120.1 kN2、計(jì)算簡(jiǎn)圖各跨的計(jì)算跨度為:中間跨: =6600-400+400=6600mm邊跨: =6600120200+370/2+400/2=6665mm1.025+b/2=1.025（6600120200）+400/26637mm,取小值6637mm平均跨度: =(6637+6600)/2=6619mm跨度差: (6637-6600)/6600=0.56%<10%主梁的計(jì)算簡(jiǎn)圖見(jiàn)圖23。 3、內(nèi)力計(jì)算: (1) 彎距計(jì)算 (值由附表51查得)邊 跨: =78.586.637=521.5 kN=120.16.637=797.1 kN中 跨: = 78.586.6=518.6kN=120.16.6=792.7kN平均跨: =78.586.619=520.1kN=120.16.619=795kN主梁彎矩計(jì)算見(jiàn)表11。(2) 剪力計(jì)算 (值由附表查得)剪力計(jì)算見(jiàn)表12。主梁彎矩及剪力包絡(luò)圖見(jiàn)圖24主梁彎矩計(jì)算 表11項(xiàng)次荷載簡(jiǎn)圖恒載0.244127.278.2-0.267-138.90.06734.70.06734.7-0.267-138.9活載0.289230.4194.5-0.133-105.7-105.7-105.7-0.133-105.7活載-35.6-70.7-0.133-105.70.200158.50.200158.5-0.133-105.7活載0.229182.599.8-0.311-247.275.90.170134.8-0.089-70.8活載-23.9-47.3-0.089-70.80.170134.875.9-0.311-247.2內(nèi)力組合+357.6272.7-244.6-71-71-244.6+91.67.5-244.6193.2193.2-244.6+309.7178-386.1110.6169.5-209.7+103.330.9-209.7169.5110.6-386.1最不利內(nèi)力組合項(xiàng)次+組合值(kNm)91.67.5-386.1-71-71-386.1組合項(xiàng)次+組合值(kNm)357.6272.7-209.7193.2193.2-209.7 4、正截面強(qiáng)度計(jì)算(1) 確定翼緣寬度主梁跨中按T形截面計(jì)算邊跨：=6.37/3=2.2123m =0.3+5.7=6.0m 取 =2.2123m中間跨：=6.6/3=2.2m=0.3+5.7=6.0m 取 =2.2m支座截面仍按矩形截面計(jì)算(2) 判斷截面類(lèi)型 取=640mm（跨中），=610mm（支座）=1.09.62212.380(640-80/2) =1019.42 kNm357.6 kNm(193.2 kNm) 屬于第一類(lèi)T形截面 主梁剪力計(jì)算 表12項(xiàng)次荷載簡(jiǎn)圖恒載0.73357.6-1.267-99.561.00078.58活載0.866104.0-1.134-136.200活載-0.133-16-0.133-161.000120.1活載0.68982.7-1.311-157.51.222146.8活載-0.089-10.7-0.089-10.70.77893.4(kN)組合項(xiàng)次+組合值41.6-257.1172(kN)組合項(xiàng)次+組合值161.6-110.3225.4（3） 截面強(qiáng)度計(jì)算 主梁正截面強(qiáng)度計(jì)算見(jiàn)表135、斜截面強(qiáng)度計(jì)算：主梁斜截面強(qiáng)度計(jì)算見(jiàn)表14表中 G+P=78.58+120.1=198.68 KN 主梁正截面強(qiáng)度計(jì)算 表13截面邊跨中B支座中間跨中M(kNm)357.6-386.1193.2-71(kN)_198.6839.74_(kNm)357.6-346.36193.2-710.0410.3230.0220.0100.9790.7970.9890.995(mm2)1902.52298.11017.4371.6選用鋼筋225(彎)320(直)118+325 (彎)216+120 (直)216(直)118+125 (彎)216(直)2443.61147.3402 主梁斜截面強(qiáng)度計(jì)算 表14截面A支座B支座左B支座右(kN)161.6257.1225.4(kN)0.251.09.6300610=439.2kN>V截面滿(mǎn)足要求(kN)0.71.1300610=140.91kN<V按計(jì)算配箍箍筋直徑和肢數(shù)6200 雙肢140.911000+1.25210228.3610200=186.23kN(mm2)0(257.1-186.23)10000.83000.707=417.7(225.4-186.23)10000.83000.707=230.8彎起鋼筋125125118實(shí)配彎起鋼筋面積(mm)490.9490.9254.56、主梁吊筋計(jì)算 由次梁傳給主梁的集中荷載為:=1.3547.28+1.01.392.4=183.9kN=433.5mm2選用218(509 mm2)7、根據(jù)計(jì)算結(jié)果及主梁的構(gòu)造要求，繪主梁配筋圖, 見(jiàn)圖25。