钢筋混凝土单向板肋梁楼盖课程设计计算书一、设计资料某建筑现浇钢筋混凝土楼盖,建筑轴线及柱网平面见图1。层高4.5m。楼面可变荷载原则值5kN/m2,其分项系数1.3。楼面面层为30mm厚现制水磨石,下铺70mm厚水泥石灰焦渣,梁板下面用20mm厚石灰砂浆抹灰梁、板混凝土均采用C25级;钢筋直径≥12mm时,采用HRB335钢,直径12mm,采用HPB235钢。二、构造布置楼盖采用单向板肋形楼盖方案,梁板构造布置及构件尺寸见图1。图1单向板肋形楼盖构造布置三、板计算板厚80mm。板按塑性内力重分布办法计算,取每m宽板带为计算单元,关于尺寸及计算简图如图2所示。图2板计算简图1.荷载计算30mm现制水磨石0.65kN/m2截面位置M(kN·m)sMfbh2ξ112sAξfbhcsf0(mm2)实配钢筋边跨跨中B支座中间跨跨中①-②④-⑤轴线间②-④轴线间Φ10@140,561mm2Φ8/10@140,460mm2Φ8@140,359mm2Φ6/8@140,281mm2kk01020cty70mm水泥焦渣14kN/m3×0.07m=0.98kN/m280mm钢筋混凝土板25kN/m3×0.08m=2kN/m220mm石灰砂浆17kN/m3×0.02m=0.34kN/m2恒载原则值g=3.97kN/m2活载原则值q=5.0kN/m2荷载设计值p=1.2×3.97+1.3×5.0=11.26kN/m2每米板宽p=11.26kN/m2.内力计算计算跨度板厚h=80mm,次梁b×h=200mm×450mm边跨l=2600-100-120+80/2=2420mm中间跨l=2600-200=2400mm跨度差(2420—2400)/2400=0.8310%,故板可按等跨持续板计算。板弯矩计算截面位置边跨跨中弯矩系数α1/11弯矩M=αpl02(kN·m)1/11×11.26×2.422=5.99B支座-1/14-1/14×11.26×2.422=-4.67中间跨跨中1/161/16×11.26×2.42=4.053.配筋计算中间C支座-1/16-1/16×11.26×2.42=-4.05b=1000mm,h=80mm,h=80-20=60mm,f=11.9N/mm2,f=1.27N/mm2,f=210N/mm2对轴线②~④间板带,考虑起拱作用,其跨内2截面和支座C截面弯矩设计值可折减20%,为了以便,近似对钢筋面积折减20%。c0y5.990.1400.151513-4.670.1090.1163944.050.0950.13404.05×0.80.0760.079269中间C①-②④-⑤-4.050.0950.1340Φ8@140,359mm2支座轴线间②-④轴线间-4.05×0.80.0760.079269Φ6/8@140,281mm2其中ξ均不大于0.35,符合塑性内力重分布条件。2811000800.35%min0.2%及45ftf451.270.27%210y板模版图、配筋图见图3。板钢筋表见下表。编号形状尺寸板钢筋表直径(mm)长度(mm)数量备注(1)Φ103440168弯起30(2)Φ102730168(3)Φ84160462(4)Φ82700420(5)Φ64160126(6)Φ62680168(7)Φ61630351(8)Φ6580378(9)Φ683040图3板模版图、配筋图四、次梁计算b=200mm,h=450mm。次梁按塑性内力重分布办法计算,截面尺寸及计算简图见图4。图4次梁计算简图截面位置次梁剪力计算剪力系数β剪力V=βpln(kN·m)kkn21.荷载计算由板传来恒载3.97kN/m2×2.6m=10.32kN/m次梁自重25kN/m3×0.2m×(0.45-0.08)m=1.85kN/m次梁抹灰17kN/m3×0.02m×(0.45-0.08)m×2=0.25kN/m恒载原则值g=12.42kN/m活载原则值q=5kN/m2×2.6m=13kN/m荷载计算值p=1.2×12.42+1.3×13=31.8kN/m2.内力计算计算跨度主梁b×h=300mm×800mm边跨净跨ln1=5900-120-150=5630mm计算跨度l01=5630+250/2=5755mm中间跨净跨ln2=6000-300=5700mm计算跨度l02=l=5700mm跨度差(5755-5700)/5700=0.96%10%故次梁可按等跨持续梁计算。次梁弯矩计算截面位置弯矩系数α弯矩M=αpl02(kN·m)边跨跨中1/111/11×31.8×5.7552=95.75B支座-1/11-1/11×31.8×5.7552=-95.75中间跨跨中1/161/16×31.8×5.72=64.57中间C支座-1/16-1/16×31.8×5.72=-64.57边支座A0.40.4×31.8×5.63=71.6B支座(左)0.60.6×31.8×5.63=107.4B支座(右)0.50.5×31.8×5.7=90.63中间C支座0.50.4×31.8×5.7=90.633.配筋计算正截面承载力计算次梁跨中截面按T形截面计算,其翼缘宽度为边跨bf’=1/3×5755=1918mm2600mm中跨bf’=1/3×5700=19002600mmMbf’Mξ112sAξfbhc0(mm2)实配钢筋804mm2911mm2603mm2628mm2216+218,416,216+212,316,0f0t00ctyvwhh=450mm,h=450-35=415mm,h’=80mmfbh(hf)=11.9×1900×80(415-80)=678kN·m95.75kN·mcff022故次梁跨中截面均按第一类T形截面计算。次梁支座截面按矩形截面计算b=200mmfc=11.9N/mm2,fy=300N/mm2截面位置(kN·m)(mm2)sfbh2sf边跨中95.7519180.025c00.025782yB支座-95.752000.2340.271892中间跨中64.5719000.0170.017532C支座-64.572000.1580.173570其中ξ均不大于0.35,符合塑性内力重分布条件。6030.67%0.2%及45ft451.270.19%200450斜截面受剪承载力计算minf300yb=200mm,h=415mm,f=11.9N/mm2,f=1.27N/mm2,f=210N/mm2,h/b=2.07540.25βcfcbh=0.25×1.0×11.9×200×415=247kNV,截面适当。0.7fbh=0.7×1.27×200×415=73.8kNnA1228.30.149%0.24ft0.241.270.145%svsvbs200190sv,minfyv210满足构造Smax为200mm,dmin为6mm规定。次梁钢筋布置图见图5。截面位置V(kN)V0.7fbh1.25fnAsv1h实配钢箍est0yvs0边支座A71.6Ves=73.8+41.1=114.9Φ6@150B支座(左)107.4Ves=73.8+41.1=114.9Φ6@150B支座(右)90.63Ves=73.8+32.5=106.3Φ6@190C支座90.63Ves=73.8+32.5=106.3Φ6@190b图5次梁钢筋布置图五、主梁计算b=300mm,h=800mm。主梁按弹性理论计算bh330803主梁线刚度ib12/lb12/7801641cm3bh340403柱线刚度ib12/l012/450474cm3考虑现浇楼板作用,主梁实际刚度为单独梁刚度2倍,即i216416.9275i4740故主梁视为铰支在柱顶上持续梁,截面尺寸及计算简图见图6。图6主梁计算简图1.荷载计算由板传来恒载12.42kN/m×6m=74.52kN主梁自重25kN/m3×0.3m×(0.8-0.08)m×2.6m=14.04kN弯矩M(kN·m)边跨跨中剪力V(kN)B支座中间跨跨中A支座项次荷载简图kMkMkMkMkMkVB支座kVkV①②③④⑤内力不利组合主梁侧抹灰17kN/m3×0.02m×(0.8-0.08)m×2.6m×2=0.64kN恒载原则值Gk=89.2kN活载原则值Qk=13kN/m×6m=78kN恒载设计值G=1.2×89.2kN=107.04kN活载设计值Q=1.2×78kN=101.4kN2.内力计算计算跨度边跨净跨ln1=7800-250-200=7350mm计算跨度l01=7350+200+370/2=7735mm中间跨净跨ln2=7800-400=7400mm计算跨度l02=7400+400=7800mml01≈l02,故按等跨持续梁计算,查表得内力系数k见下表,弯矩:M=k1Gl+k2Ql,剪力:V=k1G+k2Q。12B34AB左B右0.2440.155-0.2670.0670.0670.733-1.2671.000203.72129.41-222.9255.9455.9478.46-135.62107.040.2890.244-0.133-0.133-0.1330.866-1.1340222.58192.98-105.19-105.19-105.1987.81-114.990-0.044-0.089-0.1330.2000.200-0.133-0.1331.000-34.8-69.6-105.19158.18158.18-13.49-13.49101.40.2290.125-0.3110.0960.1700.689-1.3111.222181.1298.87-245.9875.93134.4669.86-132.93123.91-0.030-0.059-0.0890.1700.096-0.089-0.0890.778-23.73-46.66-70.39134.4675.93-9.02-9.0278.89①+②432.3322.4-328.1-49.25-49.25166.3-250.6107.04①+③168.959.81-328.1214.1214.164.97-149.1208.40h①+④384.8228.3-468.9131.9190.4148.3-268.6230.95①+⑤179.9982.75-293.3190.4131.969.44-144.6185.93.内力包络图主梁内力包络图见图7。图7主梁内力包络图4.配筋计算正截面承载力计算主梁跨中截面按T形截面计算,其翼缘宽度为bf’=1/3×7800=2600mm6000mmhf’=80mm,h=800mm,h=800-40=760mmfbh(hf)=11.9×2600×80(760-80)=1782kN·m432.3kN·mcff022故主梁跨中截面均按第一类T形截面计算。主梁支座截面按矩形截面计算b=300mm,h0=800-80=720mmB支座边M=MB,max-0.2VB右=468.9-0.2×230.95=422.71kN·m。fc=11.9N/mm2,fy=300N/mm2截面位置M(kN·m)bf’h0(mm2)(mm2)sMfb(或b)h2cf0ξ112Ac0ξfbhsf实配钢筋sy边跨中432.326007600.0240.0241881mm2522,1900mm2322+2B支座-422.713007200.2280.2622245mm218+220,2277mm2中间跨中418,1017mm2支座628mm2中间220,tyvtynA截面位置V(kN)V0.7fbh1.25fnAsv1esyvh0实配钢箍t0s边支座AB支座(左)B支座(右)166.3268.6230.96Ves=199+85.5=284.5VVe