混凝土設(shè)計(jì)復(fù)習(xí)題

1、1.用剪力分配法求圖1排架柱頂剪力，并作出彎矩圖（20分）已知：作用在牛腿頂面的彎矩MB=165kN，m,MC=90kN，m；各柱圜生矩:11A=2,13>d09mm3C。二.-2.4831311(1)10.33(1)n0.147,12A=14.52父109mm4；9494I1B=5.21x109mm4,12B=17.76父109mm4；9494I1C=2.13義109mm4,12C=15,38義109mm4IC2C提示：C03311'3(-1)nEI|C°C3231-2311,(-1)nIuIiHu解：1.計(jì)算剪力分配系數(shù)A柱：一一9一2.131014,5290.03

2、.610.9=0.33,AB柱:C0,Bc柱:C010900335.96EI1C0E14.521092.48-95.211017.76109=0.293,九=210.9=0.33311(-1)n10.333二2.761<0.29310900326.42EI1coE17.761092.76-92.131015.38109=0.138二邈12.9=0.279-'3(-1)n10.27931=2.64<0.138)H312900352.87EIlC0E15.381092.64,B、c'B35.96E=0.329E35.9626.4252.872.柱頂剪力計(jì)算C3B26.4

3、2E=0.447E1-235.9626.4252.8752.87一e二0.22435.9626.4252.8721-0.332310.33(0.293-1)=1.23C3c31一221-3(-1)n1-0,27923110.2793(-1)0.138=1.218Mb_165RB=-C3B=x1,23=18.62kN(5H10.9Mc_90RcCC3C=1.218=8.50kNH12.9R=RB_RC=18.62-8.50=10.12kN(<)VA=AR=0.32910.12=3.33kN(fVB=BR-RB=0.44710.12-18.62=-14.10kN(一VC=%R+RC=0.22

4、4x10.12+8.50=10.77kN(->)3.作彎矩圖M圖(kN-m)47 .某單層單跨廠房，跨度18m,柱距6m,內(nèi)有兩臺(tái)10t中級載荷狀態(tài)的吊車，試求該柱承受的吊車豎向荷載Dmin、Dmax和橫向水平荷載Tmax。起重機(jī)有關(guān)數(shù)據(jù)如下：吊車跨度LK=16.5m,吊車寬B=5.44m,輪距K=4.4m,吊車總質(zhì)量18.23t,額定起重量10t,最大輪壓標(biāo)準(zhǔn)值Pmax,k=104.7KN。5.44m5.44m,4.4mL,4.4mj-£.j-一一Pmin,k=2"%Fax'k'gFax-=父1。-45kN62226m6m1.6/64.96/60.5

5、6/6查表，p=0.9,豎向反力影響線如圖所示:則有:Dmax=-rQPmax,k.二yi-0.91.4104.7(10.56164.96=288.47kNDmin=DmaxPmin,kPmax,k36.45=288.47100.4kN104.70.120.9(3.68410)10=3.69kNTmax=DmaxPmax,k3.69=288.4710.17kN104.748 .試用剪力分配法求圖所示排架，在風(fēng)荷載作用下各柱的內(nèi)力。已知基本風(fēng)壓切0=0.45kN/m2,15m高處的叱=1.14(10m高匕=1.0),體形系數(shù)也示于圖中。柱截面慣性距：_94_94_94_94I1=2.13父109

6、mm4,I2=14.38父109mm4,13=7.2父109mm4,14=19.5109mm4.上柱高3m,計(jì)算單元寬度取B=6m。解：1.求q1，q2114-10線性差值：巳=14、0(10.510)=1.01415-10q1k=s，0B=0.81.0140.456=2.19kN/mq2k二二sz0B=0.51.0140.456=1.37kN/m=rQq1k=1.42.19=3.07kN/m(，)q2=rQq2k=1.41.37=1.92kN/m()風(fēng)向m1m22.局度取10.5+2.1=12.6m114-10zWk=1L二(12.6-10)=1.0715-10=(0.80.5)h1(0.5

7、-0.6)h2Jz0B=1.32.1-0.11.21.070.456=7.54KN=rQWk=1.47.54=10.56kN3 .計(jì)算參數(shù),nnA柱：11I2HuH2.131099-0.1514.3810=0.2910.5B柱:I3I4HuH7.21099=0.3719.510二=0.2910.54 .在柱頂虛擬加不動(dòng)錢支座查表計(jì)算：A柱：C11B柱：C11314(1-1)n31813(-1)n,1314(-1)n310.294(810.293(310.294(10.1510.1510.37-1)-1)-1)=0.3431甲3(1)n31810.293(1)0.37=0.36Ra=q1HC11

8、=3.0710.50.34-11()RB=q2HC11=1.9210.50.36=-7.3(，)故：柱頂剪力Va,1=Ra=-11()Vb,1=Rb=-7.3G)3311-0.293(0.15=2.64-1)5 .撤消不動(dòng)錢支座，反向施加支座反力。A柱：C0=3113('-1)nB柱:Co3311(-1)n310.29(0.37-1)=2.882bH310.53EcIlC。9Ec19.5102.88所以分配系數(shù):2.6414.382.6414.382.8819.52.8819.52.6414.382.8819.5H310.53EJC0Ec914.381092.64=0.4=0.6故，柱

9、頂剪力：Va,2="a(Ra+Rb+W)=0.4父(11+7.3十10.56)=11.54kN(T)Vb,2="b(Ra+Rb+W)=0.6父(11+7.3+10.56)=17.32kN(T)6 .疊加兩個(gè)受力狀態(tài)Va=Va,iVa,2=11.54-11=0.54(>)Vb=Vb,i+Vb,2=17.327.3=10.02(T)7 .繪制彎矩圖A柱M圖(KNm)B柱M圖(KNm)B柱的內(nèi)13-2。49.如圖所示排架，在A,B牛腿頂面作用有力矩M1和M2。試求A,力，已知：M1=153.2KN.M,M2=131.0KN.M,柱截面慣性距同上習(xí)題解：1.計(jì)算參數(shù),nA柱:

10、9I12.1310一一9I214.38109=0.15B柱:I4H_97.21019.5109=0.37Hu3-=0.29H10.510.5=0.292.在柱頂虛擬加不動(dòng)錢支座A柱：C31-'24511"(1-1)n=1.51-0.2923110.29(-1)0.15=1.212 2B柱：C3=1.321-'1-0.29=1.5=1.53 1311(-1)10.293(1)n0.37M1153.2Ra1C3=1.21-17.65kN(，)故：H佃5M2131.0Rb=2c3=F.32-16.47kN(>)H10.53 .撤消不動(dòng)錢支座，反向施加支座反力R=RaR

11、b=17.65-16.47=1.18kN(>)A=0.4,B=0.6所以:VA=Ra=1.180.4=0.47kN(>)VB=RB=1.180.6=0.71kN(>)4 .疊加內(nèi)力VA=-17.650.47=-17.18(VB=16.470.71=17.18(>)5 .彎矩圖：M=131KN.mM=153.2KN.m17.18KN50.如圖所示柱牛腿,已知豎向力設(shè)計(jì)值Fv=324kN,水平拉力設(shè)計(jì)值Fh=78kN,采用C20(ftk=1.54N/mm2)混凝土和HRB335級鋼筋,試設(shè)計(jì)牛腿的縱向受力鋼筋。（截面寬度b=400mm（另加的條件）Ci=250Fh=78KN

12、1050Fv=324KN解：1 .驗(yàn)算截面尺寸h0=800-40=760mm-(1-0.5Fhs)Fvsftkbhoa0.5ho=0.8(1-0.578)1.54400760=397kNFvs=324kN3240.5差0760截面尺寸滿足要求。2 .計(jì)算縱向受拉鋼筋A(yù)=Fva1.2F0.85fyh0fy2=730mm324103250781031.2-0.85300760300選配4118,As=1017mm2As10170.32%0.2%bh400800滿足最小配筋要求。51.某單層廠房現(xiàn)澆柱下獨(dú)立錐形擴(kuò)展基礎(chǔ)，已知由柱傳來基礎(chǔ)頂面的內(nèi)力：N=920KN,M=276KN.M,V=25KN,柱

13、截面尺寸bxh=400mmx600mm,地基承載力fa=200kN/m2,基礎(chǔ)埋深1.5m,基礎(chǔ)采用C20混凝土，HPB235級鋼筋，試設(shè)計(jì)此基礎(chǔ)并繪制基礎(chǔ)平面圖，剖面和配筋圖。解：1.初步確定基礎(chǔ)高度和杯口尺寸取插入深度：h1=600mm,故，杯口深度為600+50=650mm；杯口頂面尺寸：寬為400+75父2=550mm,長為600+75父2=750mm；杯壁厚度取為t=200mm；杯底厚度取為a=200mm；其他截面尺寸：h2=300mm；a2=200mm;所以，初步確定基礎(chǔ)的圖度為60050200=850mm2,確定基礎(chǔ)底面積A-920fa-rmd200-201.52=5.41m增加

14、20%40%,初步選定尺寸為：B=3,5m,l=2m；A=7m2W=T上二4e6G=rmbld=203,521.5=210kNFGMcVchbl920210276250.852=234kN/m223.54.1blMcVchW920210276250.8523.54.12=88.9kN/m(1)Pmax=234kN/m<1,2fa=240kN/m2a(2)Pmax-Pmin23488.9=161,4：二fa=200kN/m2故，基礎(chǔ)底面尺寸滿足要求。3 .驗(yàn)算基礎(chǔ)高度地基凈反力的計(jì)算。Pn,maxFMcVchblW920276250.85+23.54.1=203.9kN/m2Pn,minF

15、-Mh二里一276250.85:58.9kN/m2blW23.54.1僅需對臺(tái)階下基礎(chǔ)做沖切驗(yàn)算:h0=550-40=510mm沖切面：bt=4002275=950mmbb=9502510=1970mmbt-bbbm=J=1.46m2沖切荷載計(jì)算面積：bhtlbt2A七一萬2一(2一丁h0)3.521.1522-0.51)l-(20.9522-0.51)2=1.33m2Fl=psA=R,maxA=203.9m1.33=271.2kN203.9Fl=psA=P.,maxA=203.9父1.33=271.2kN0.7ftbmhfe-0.71.11.46510-573.3kNF1V271.2kN故，基礎(chǔ)高度滿足抗沖切承載力的要求。4 .基礎(chǔ)板底配筋(1)長邊方向M1=#二Pn1)(b-hc)2(2lbc)1,203.9143.824二268kNm)(3.5-0.6)2(220.4)h01=850-40=810mmM12681060.9fyh010.9210810=1751mm