鋼筋混凝土單向板肋梁樓蓋課程設(shè)計(jì)步驟

解：（1）樓蓋梁格布置及截面尺寸梁格布置見附圖截面尺寸板厚:取h=80mmEQ\F(L0,40)=EQ\F(2080,40)=52mm次梁:h=(EQ\F(1,18)～EQ\F(1,12))L0=(EQ\F(1,18)～EQ\F(1,12))×6200=344.4～516.7mm取h=400mmb=200mm主梁:h=(EQ\F(1,14)～EQ\F(1,8))L0=(EQ\F(1,14)～EQ\F(1,8))×6240=445.7～780mm取h=600mmb=300mm(2)樓板設(shè)計(jì)（按考慮塑性內(nèi)力重分布設(shè)計(jì)）①荷載計(jì)算水磨石面層:0.65×1.2=0.78KN/㎡平頂粉刷:0.25×1.2=0.30KN/㎡樓蓋自重:1.2×25×0.08=2.40KN/㎡恒荷載設(shè)計(jì)值:g=3.48KN/㎡活荷載設(shè)計(jì)值:q=1.3×6.5=8.45KN/㎡總荷載設(shè)計(jì)值:g+q=11.93KN/㎡②計(jì)算簡圖邊跨:L0=Ln+EQ\F(h,2)=1740+EQ\F(80,2)=1780mm中間跨:L0=Ln=2080-200=1880mm跨度差:EQ\F((1880-1780),1780)=5.6%<10%可按等跨計(jì)算.取1m寬板帶作為計(jì)算單元,其計(jì)算簡圖見下圖。彎矩設(shè)計(jì)值邊跨跨中:M1=EQ\F(1,11)(q+g)L02=EQ\F(1,11)×11.93×1.782=3.4363KN·m第一內(nèi)支座:MB=-EQ\F(1,14)(q+g)L02=-EQ\F(1,14)×11.93×1.882=-3.01KN·m中間跨中及中間支座:M2=M3=-MC=EQ\F(1,16)(q+g)L02=EQ\F(1,16)×11.93×1.882=2.64KN·m④配筋計(jì)算b=1000mmh=80mmh0=80-20=60mmfc=11.9N/mm2(C25混凝土)fy=210N/mm2（板內(nèi)配置Ⅰ級鋼筋）計(jì)算過程見表1-1。因板的內(nèi)區(qū)格四周與梁整體連結(jié)，故其彎矩設(shè)計(jì)值可降低20%，計(jì)算結(jié)果列于表括號內(nèi)，板中受力鋼筋的配置情況也列于表中，配筋圖見附圖：表1-1板的配筋計(jì)算截面第一跨中支座B第二、三跨中支座C彎矩設(shè)計(jì)值(NN·mm))34363000-3010000026400000(21120000)-26400000(-21120000)ɑs=M/(ɑ1ffcbh02)0.08020.0700.062(0.049)0.062(-0.049))ξ0.0837<<0.3550.0730.064(0.050)0.064(0.050)As=(ξɑ1fcbhh0)/fy(mmm2)284.58248.2217.6(170.89))217.6(170.89))選配鋼筋(A)～（B）、(C)～（D）軸線Φ8/10@2000(307.9mmm2)Φ8@200(251.5mmm2)Φ8@200(251.5mmm2)Φ8@200(251.5mmm2)（B）～（C）軸線線Φ8/10@2000(307.9mmm2)Φ8@200(251.5mmm2)Φ6/8@2000(207.5mmm2)Φ6/8@2000(207.5mmm2)（3）次梁設(shè)計(jì)（按考慮塑性內(nèi)力重分布設(shè)計(jì)）①荷載計(jì)算板傳來的恒荷載設(shè)計(jì)值：3.48×2.08=7.2384KN/m次梁自重設(shè)計(jì)值:1.2×25×0.2×(0.4-0.08)=1.92KN/m次梁粉刷重設(shè)計(jì)值:1.2×0.25×(0.4-0.08)×2=0.192KN/m恒荷載總設(shè)計(jì)值:g=7.2384+1.92+0.192=9.35KN/m活荷載設(shè)計(jì)值:q=8.45×2.08=17.576KN/m總荷載設(shè)計(jì)值:g+q=26.926KN/m②計(jì)算簡圖(計(jì)算簡圖見下圖)取主梁截面為300mm×600mm，則計(jì)算跨度為：邊跨：L0=Ln+EQ\F(a,2)=5810+EQ\F(240,2)=5930mm<1.025Ln=1.025×5810=5955.25mm中間跨：L0=Ln=6200-300=5900mm邊跨與中間跨跨度差：EQ\F(5.93-5.9,5.9)=0.51%<10%故可按等跨連續(xù)梁計(jì)算③內(nèi)力計(jì)算彎矩設(shè)計(jì)值：M1=-MB=EQ\F(1,11)(g+q)L02=EQ\F(1,11)×26.926×5.932=86.08KN·mM2=EQ\F(1,16)(g+q)L02=EQ\F(1,16)×26.926×5.92=58.58KN·m剪力設(shè)計(jì)值：VA=0.4(g+q)Ln=0.4×26.926×5.81=62.576KNVBL=0.6(g+q)Ln=0.6×26.926×5.9=95.32KNVBR=0.5(g+q)Ln=0.5×26.926×5.9=79.43KN正截面受彎承載力計(jì)算支座截面按矩形截面b×h=200mm×400mm計(jì)算，跨中截面按T形截面計(jì)算，其受壓翼緣計(jì)算寬度取下面較小值：邊跨bf′=L0/3=5930/3=1976.7mm<(b+s0)=200+1880=2080mm中間跨bf′=L0/3=5900/3=1966.7mm故取bf′=1967mm梁高400mm，支座、跨中均按布置一排縱筋考慮，故均取h0=400-35=365mm，跨中hf′=80mmfy=300N/mm2(次梁受力筋配Ⅱ級鋼筋)判別T形截面類型：ɑ1fcbf′hf′(h0-hf′/2)=1.0×11.9×1967×80×(365-80/2)=608.6KN·m與上述計(jì)算彎矩值比較可知，各跨中截面均屬第一類T形截面。計(jì)算過程與實(shí)際配筋見下表：表1-2次梁正截面承載力計(jì)算截面1B2彎矩設(shè)計(jì)值（KN·m）86.08-86.0858.58ɑs=M/(ɑ11fcbf′h02)0.0276(bf′=1967mm))0.2715(bf′=b=200mmm)0.0188(bf′=1967mm))ξ0.0280.324<00.350.019As=(ξɑ1fcbhh0)/fy(mmm2)797.41938.2541.1配筋218+1222322+118218+118實(shí)配As(mm2)889.11394.1763斜截面承載力計(jì)算驗(yàn)算截面尺寸：hW=h0-h1=365-80=285mmhW/b=285/200=1.425<4VBL/βcfcbh0=95.32×103/(1.0×11.9×200×365)=0.11<0.25且>0.1截面尺寸滿足要求，但需按計(jì)算配置箍筋。S≦(1.25fyvAsvh0)/（VBL-0.7ftbh0）=EQ\F(1.25*210*56.6*365,95.32*1000-64.9*1000)\F(,)=178.3mm取S=170mm≦Smax=200mmρsv=Asv/bS=EQ\F(56.6,200*170)=0.1665%ρmin=0.24*ft/fyv=0.24EQ\F(1.27,210)=0.145%有ρsv>ρmin故符合要求。同理采用表1-3求得中間跨選用雙肢箍筋也能滿足要求。表1-3次梁斜截面承載力計(jì)算截面AB（左）B（右）V（N）6257695320794300.7ftbhh0(N)64900<VVA64900<VVBL64900<VVBR箍筋肢數(shù)、直徑徑2Ф62Ф62Ф6Asv=nAsvvl56.656.656.6S=(1.25ffyvAsvh0)/（V-0..7ftbh0）(mm)(300)構(gòu)造要求178.3373.23實(shí)配箍筋間距（mm）170170170（4）主梁設(shè)計(jì)（按彈性理論計(jì)算）①荷載及計(jì)算簡圖（主梁自重按集中荷載考慮）次梁傳來的集中荷載：9.35*6.2=57.97KN主梁自重：1.2*25*0.3*（0.6-0.08）*2.08=9.7344KN主梁粉刷重：1.2*0.25*（0.6-0.08）*2*2.08=0.65KN恒荷載設(shè)計(jì)值：G=68.353KN活荷載設(shè)計(jì)值：Q=17.576*6.2=109KN設(shè)計(jì)總荷載：G+Q=177.353KN由于主梁線剛度比鋼筋混凝土柱的線剛度大許多倍，因此主梁中間支座按鉸支座考慮。主梁梁端支撐在磚壁柱上，其支撐長度為370mm.主梁跨度分別為：邊跨L0=Ln+EQ\F(a,2)+EQ\F(b,2)=5825+EQ\F(370,2)+EQ\F(350,2)=6185mmL0=1.025Ln+EQ\F(b,2)=1.025*5825+EQ\F(350,2)=6145.625mm取較小值L0=6145mm,中間跨0.05Lc=0.05*6240=312mm<a=350mmL0=1.05Ln=1.05*5890=6184.5mm因各跨跨度相差小于10%，故可按等跨連續(xù)梁的彎矩及剪力系數(shù)計(jì)算內(nèi)力。計(jì)算簡圖見下圖。②內(nèi)力計(jì)算彎矩和剪力的計(jì)算公式為M=k1GL0+k2QL0V=k1G+k2Q主梁的內(nèi)力計(jì)算結(jié)果及最不利內(nèi)力組合見表1-4。按此繪出的彎矩、剪力包絡(luò)圖見下圖。③主梁正截面承載力計(jì)算支座按矩形截面（300mm*600mm）計(jì)算?？缰邪碩形截面計(jì)算，其翼緣計(jì)算寬度bf′=L/3=6240/3=2080<(b+s0)=300+6200-300=6200mm取bf′=2080mm支座、跨中按兩排布置鋼筋。支座h0=h-60=600-60=540mm跨中h0=h-60=600-60=540mm判別T形截面類型:ɑ1fcbf′hf′(h0-hf′/2)=1.0*11.9*2080*80*(540-EQ\F(80,2))=990.08*106N·mm>Mmax=382.73*106N·mm顯然各跨中截面均屬于第一類截面.正截面承載力計(jì)算見表1-5。表1-5主梁正截面承載力計(jì)算截面1B、E2C、D3M（KN·m）428.22-332.766-160.700382.73-289.411205.27-19.21M-V0b/22(KN·m)—-294.088——-254.533——bf′h0或bh(mm)2080*5440300*5400300*54002080*5440300*54002080*5440300*5400ɑs=M/(ɑ11fcbf′h02)0.0593330.28250.1543770.0530330.24450.0284440.018455ξ0.06120.3404550.1685880.0545220.2851660.02885560.01862234As=(ξɑ1fcbhh0)/fy(mmm2)2726.6882187.7661083.29922428.88841832.4221285.6554119.674407配筋425+222225+2222+2222+1166225+1222425+2222225+2222+116422216實(shí)配AS（mm2）27242703.34421361.888127241943.07761520.5332402.1244主梁斜截面承載力計(jì)算（見表1-6）表1-6主梁斜截面承載力計(jì)算截面位置邊支座（VA）B支座左側(cè)(VB左)B支座右側(cè)（VB右）C支座左側(cè)(VC左)C支座右側(cè)（VC右）V(Kn)142.89-231.333210.7-194.811203.850.25fcbbh0(Kn)0.25*111.9*3300*5540=44819550N=4481.995KN>>VA、VB左、VB右、VC左、VC右。截面滿足要求求0.7ftbhh0(Kn)0.7*1.227*3000*5440=1