楼盖设计1楼面梁格布置图图12.1楼面梁格布置图2荷载设计值(1)活荷载标准值:q=2.0kN/m2(室内),q=2.5kN/m2(走道)(2)恒荷载标准值:20厚花岗石面层0.02×15=0.3kN/m220厚水泥砂浆找平层0.02×20=0.4kN/m2100厚钢筋混凝土现浇板0.10×25×1.1=2.75kN/m2V型龙骨吊顶0.20kN/m2g=3.65kN/m2(3)设计值:q=1.4×2.0=2.8kN/m2(室内),q=1.4×2.5=3.5kN/m2(走道)g=1.2×3.65=4.38kN/m2室内222mkN4.128.22mkN78.528.238.42mkN18.78.238.4qqgqg,走道222mkN75.125.32mkN13.625.338.42mkN88.75.338.4qqgqg3方案确定(弹性理论)(1)AB跨:2l02/l01=9000/3600=2.503,宜按双向板考虑。(2)BC跨:2l02/l01=8100/3000=2.703,宜按双向板考虑。4双向板计算(1)计算跨度:l0=lc,lc为轴线距离(梁柱不偏心)A区格板l01=3.0m,l02=8.1m(2)弯矩计算1)满布荷载时,g+q/2=6.13kN/m2,布与板上时lx/ly=3.0/8.1=0.37,支承方式四边固定。查表得:0400.0xm,0038.0ym,0829.0xm,0570.0ym2)间隔布置时,2kN/m75.12q,A区格板lx/ly=3.0/8.1=0.37,支承方式三边简支,一边固定。查表得:0646.0xm,0063.0ym3)弯矩计算(泊松比ν=0.2)A板:201201122lqmmlqgmmmxyyx220.375.10646.02.00063.00.313.60038.02.00400.0=2.55kN.m/m201201222lqmmlqgmmmyxxy220.375.10063.02.00646.00.313.60400.02.00038.0=1.69kN.m/mmkN88.50.388.70829.00829.0220111lqgmmmkN04.40.388.70570.00570.0220122lqgmm4)截面设计截面有效高度:选用C8钢筋为受力主筋,则l01(短跨)方向跨中截面的mm81415100201dchhl02(长跨)方向跨中截面的mm7312151002302dchh支座截面处h0均为81mm计算配筋量,取内力臂系数γs=0.95,ysfhmA095.0,截面配筋表如下:表12.1双向板配筋表项目h0(mm)m(kN.m/m)As(mm2)配筋实配As(mm2)截面跨中A区格l01812.5592C8@200251l02731.6968C8@200251支座A支座l02方向81-4.04146C8@200251A-B81-5.88212C8@2002515次梁计算次梁与主梁整体现浇,混凝土等级采用C30。钢筋采用HRB400级;主梁尺寸250mm×600mm,次梁尺寸250×500mm;计算跨度l0=ln=8100-500=7600mm5.1荷载恒载:g=1.2×[3.65×2.25+(0.50-0.10)×0.25×25×1.1]=13.16kN/m活载:q=1.4×2.0×2.25=6.30kN/mg+q=13.16+6.30=19.46kN/m5.2正截面受弯计算承受正截面的跨中截面按T形截面计算。跨中:mkN50.4016.746.198181220lqg计算跨度:m53.236.730lbf由于mkN43.1501210046510025303.140.120c1fffhhhbf140.50kN.m,故属于第一类T形截面。次梁同主梁,采用HRB400级钢筋(2mmN360yyff),518.0b018.046525303.140.11050.1402620c1hbfMfsb018.0018.0211211s20c1mm16.84136046525303.140.1018.0yfsfhbfA选配钢筋4C18(As=1018mm2),%88.04652501018支座按构造配筋,4C12(As=452mm2),%39.04652504525.3斜截面受剪承载力计算1)验算截面尺寸mm3651004650fwhhh,446.1250365bhwkN03.713.746.19212qlV因为71.03kNkN59.4154652503.140.125.025.00ccbhfkN03.71kN37.11646525043.10.17.07.00tcbhf故截面尺寸符合要求,不需要配置腹筋,按构造配筋即可选用C8@200双肢箍筋。4652003.50227025.146525043.17.025.17.000tcshsAfbhfVsvyv71.03kNkN31.195(满足)2)验算配箍率%14.027043.126.026.0%20.02002503.502ytffbsAsvsv(满足)