中南大學(xué)鋼筋混凝土鐵路簡(jiǎn)支梁課程設(shè)計(jì)書

1、混礙土課程設(shè)計(jì)中南大學(xué)鋼筋混凝土鐵路簡(jiǎn)支梁課程設(shè)計(jì)書鋼筋混凝土鐵路簡(jiǎn)支梁設(shè)計(jì)第一部分課程設(shè)計(jì)任務(wù)書設(shè)計(jì)資料1、結(jié)構(gòu)型式及基本尺寸采用分片形式T形截面。梁梗中心 距道磴槽寬每片梁頂寬計(jì)算跨度梁全長(zhǎng)梁高跨中腹板厚180Cm390Cm192Cnl16 OOm16 50mL 90m30Cm2、橋上線路與人行道橋上線路為平坡、直線、單線鐵路，道確橋面；設(shè)雙側(cè)帶欄桿的人行道。3、材料混凝土： 250號(hào)鋼筋：T20MnSi及A3。板內(nèi)：受力鋼筋4> 10；分布鋼筋4>8。梁內(nèi)：縱向受 力鋼筋20;箍筋及縱向水平鋼筋架立筋4>14。4、荷載活載：列車活載:中一活載；人行道活載：距梁中心245

2、米以內(nèi)IokPa；距梁中心2. 45米以外4kPa；恒載：人行道板重1. 75kPa;欄桿及托架重（集中作用于欄桿中心）0. 76kNm （順橋）；道確及線路設(shè)備重IOkPaJ道磴槽板及梁體自重，按容重25 kNms計(jì)算。板自重可近似按平均厚 度計(jì)算。5、規(guī)范鐵路橋涵設(shè)計(jì)規(guī)范TB2005鐵路橋涵鋼筋混凝土和預(yù)應(yīng)力混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范TBlOOO2. 3-2005混礙土課程設(shè)計(jì)17105390/2103pLOII 卑II/、72.7 b9 ICOo70梁體橫截面圖（單位：Cm）二. 設(shè)計(jì)計(jì)算內(nèi)容第一部分道磴薄板的設(shè)計(jì)和計(jì)算一.荷載計(jì)算與組合1.恒載(1) 板的自重如(按平均厚度石)Al =l2&#

3、215;(12 + 15)×63 =850.5(Cm2)A2 = 1 / 2 × (12 +15) × 45 = 607.5(cm2)A3 =12×(24 + 15)×27 =526 .5(cm2)4 =1/2x(195 -3-7-24.5)×6 = 481.5(Cnr)=7xl0 = 70(2)(按矩形估算)A = A1+A2+2A3+A4+A6 = 850.5 + 607.5 + 2× 526.5 + 481.5 + 70 = 30625(cm2)板平均高度3062.563 + 27 + 27 + 45=18.904(c

4、z?)ql =IJf 人1 = 1&904x25/100 = 4.726(KN/加)(2) 道磴及線路設(shè)備重：=1。XIio(KNm)(3) 外擋殖墻重05 =30×24.5-i×8×16-2.5×16-i×12.2×6-×(2.5 + 6.1)×1.8 = 586.05(cM2)Q=人4 =25 X 586.05 Xl (T4 =1.465伙 N)©作用點(diǎn)：5x = 140×300×70 + l2× 160×80×(140 + 363) + 44

5、×140×(140 + 22)+ l2×36×18×(184 + 363) + 61 X 122/2x(184 + 61/3)=>x = 99.5mm 取為99mm o(4) 人行道板重：=I.75×1 = 1.75(Ww)(5) 欄桿及托架重：Q2=0.76kN綜上可得恒載的計(jì)算圖示如下：Ql = I. 465kN</mIJUIq1+cl2= (4725+O)kNZmIIJI T1 T ,T 1 , I AB(IEI-道殖槽板恒載受力示意圖尺寸單位：Cm(控制截面為圖中紅線所示的A、B、C、D、E五個(gè)截面) 恒載引起的內(nèi)

6、力計(jì)算：在順跨度方向取1米寬的板帶進(jìn)行計(jì)算。E截面：A/,： =1Q+丄 2=o.76x 1+ 1.75×1.0622 = 1.819Ww2Ql = 0.76 + 1.75x1.06 = 2.61 SkNA截面：r1.69MA = 0.76×(1.1 + 0.63) + L( .75XdX+1.465 X (0.63 一 0.099) + 0.5×14.726 × 0.632 =7.167伙N m)QA = 0.76 + 1.75x1.06 + 1.465 +14.726 × 0.63 = 13.357伙N)B截面：rl.69= 0.76

7、15;(1.1+ 0.63 + 0.27)+ .15xdx+1.465 × (0.63 + 0.27 - 0.099) +14.726 X (0.63 + 0.27)2/2 = 11.310W-W = 0.76 + 1.75x1.06 + 1.465 +14.726 ×0.9 = l 7.333伙 N)C截面：MC=IOX (0.48 + 0.27)2 / 2 + 4.726 X (0.45 + 0.27)2 / 2 = 4.037伙N m)c =10×0.75 + 4.726 × (0.75 一 0.03) = 10.903WD截面：MD=IoX 0.

8、482 / 2 + 4.726 X 0.452 / 2 = 1.631伙N 加)QD=IoX 0.48 + 4.726 × 0.45 = 6.927伙 N) 2.活載（1）列車活載道殖槽板的列車活載按特種活載。y莎r663V 加計(jì)算活載沖擊系數(shù)1 + “ = 1 +其中 = 2.030 +厶外懸臂板長(zhǎng)厶外=90Cm = 0.9/7?(1 + “)外=1 + 2.0×(-) = 1.38830 I 09的外=(1+“)外 <7a =1.388x66.348=92.09UWV/;n2內(nèi)懸臂板長(zhǎng)ZIlII = 12Cm = 0.12n(1 + “)內(nèi)=l + 2.0x()=

9、I391=(1 + /)內(nèi)乞紹=1.391X 66.348 = 92.290( kN / r)% = % % = 92：92.290 = 92 J9（KNm）2 2（2）人行道靜活載距梁中心2. 45m以內(nèi)：q3 = ' OkPU ;距梁中心2. 45m以外：q5 = 4kPu.活載內(nèi)力組合（分工況討論）：活載組合：有車一列車活載+2. 45m以外的人行道活載，即的+，板與人行道荷載分布圖如下：活載組合：無(wú)車一全部的人行道活載，即竹+竹，板與人行道荷載分布圖如下:Q=IOkN/mq3l,=4kNm1E . AR廠D .I. JB : FI結(jié)合前面部分的恒載計(jì)算有：板與人行道荷載分布表Q

10、I (KNm)(U(KNm)q/(kPa)QS, (kPa)as (kPa)QP(kPa)Ql (kN)Q2(kN)4. 725101041.7592.21.4650. 76板自重道磴及 線路設(shè) 備重2. 45m 以 內(nèi)2.45m 以 外人行道 步板重列車活載擋殖墻 重欄桿及 托架重活載引起的內(nèi)力計(jì)算：在順跨度方向取1米寬的板帶進(jìn)行計(jì)算。E截面：Me= ''xtx = ×4×(1.062-0.52) = 1.747伙N 加)Mir2 =丄×4×(1.062-O.52) + 10×0.5×0.52 = 2.997kN I

11、rl2?；?4x.56 = 2.24kN=4× 0.56 + 10x0.5 = 7.24WA截面：MZI=I×4x(1.692-1. 132)+92. 19 ×0.252/2 = 6.039Wm2M 淚=-×10×(l .132-0.62) + - × 4 × (1.692 -1.132) = 7.558( W m)2 2Qm= 4 X 0.56 + 92.19× 0.25 = 25.288WQsi2 = 7.24WB截面：M ,-1=×92. 19×0. 52+×4×(1

12、.962-1.42) = 16.227RNmMY=I×10×(1.42-0.92) + i×4×(1.962-1.42) = 9.5 1 3A:/V-W2 2QisIl =4× 0.56 + 92.19× 0.52 = 50.179伙N)Q 尼=7.24RNC截面：M：IrII =92.19×0.7522 = 25.92SkNmM = OkN mQIH = 92.19x0.75 = 69.143伙N)=D截面：M.,-II =92.19×0.482/2 = 10.620伙N m)= MN 加Qm =92.19 X

13、0.48 = 44.299伙N)= QkN綜合以上計(jì)算，彎矩和剪力如下表控制力M二恒載M+ max 活載M,活載M 控制力Q=恒載Q+ max 活載Q,活載Q彎矩表如下截面EABCD恒載彎矩(kNm)1.8197.16711.3104. 0371.631活載彎矩(kNm)1. 7476. 03916. 22725. 92810. 620活載彎矩 (kN m)2. 9977. 5589.513OO控制力M(kNm)4.81614.72527. 53729.96512. 251剪力表如下截面EABCD恒載剪力(kN)2.61513.35717. 33310. 9036. 927活載剪力(kN)2.

14、 2425. 28850.17969.14344. 299活載剪力(kN)7.247.247.24OO控制力Q (kN)9. 85538. 64567. 51280. 04651. 226二.板厚檢算板的凈保護(hù)層厚度取為34cm,板的受力鋼筋采用HRB33512,査鐵路橋涵 鋼筋混凝土和預(yù)應(yīng)力混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范TBlOOO2. 32005,得bj = 180M 混凝土標(biāo)號(hào)為 250,査 TBIOOO2. 32005 得巧=&5MP , / = 15“ =34 + 6 = 40("”)15x8.515x8.5 + 180bhj = 0.4172M(l-3)j取 b = bn =

15、 IOoCm截面E員BCDM ( KN/m)4.81614.72527.53729.96512.251o = 0.5588/ (Cm)5.77110.09113.814.3959.204o +a ( Cm )9.77114.09117.818.39513.204% ( Cm)1215242415= 0.5588M2M0.4418(l-0.44183)×9.5×l由上表可以看出hn = +«< %都每一個(gè)控制截面均成立，因此板厚檢算合格。三.配筋并檢算最小配筋率（查規(guī)范有Amin=O.15%）Z = 0.88?O = 0.88( . -U)截面EABCDZCm

16、)7.0496817.617.69. 68A-M 瑚J.Z3.88. 458. 699.467. 03配筋（間距Cm）12(S>111091211109一 121110 1211Q一 121110斷筋數(shù)10斷510斷110斷1不斷筋10斷2As.j.(cm2)5.149. 2529. 25210. 28& 2240.84%0.46%0.51%0.75%0.64%“min0.15%0.15%0.15%0.15%0.15%取C截面為控制截面，其所需要的面積為/V =9.84（c）査規(guī)范有C截面的配筋應(yīng)取12 11.06772 ,以C截面處配筋為基準(zhǔn)（因?yàn)?同一板內(nèi)的鋼筋距離不能取很多

17、不同的數(shù)值，故只能取距離最小的，然后通過 斷筋來(lái)避免材料的浪費(fèi)。）3 R對(duì)于 E 截面，-x 100% = 37.0%10.28S 45對(duì)于 A 截面，X100% = 82.2%10.28對(duì)于 B 截面，-XIO0% = 84.5%10.28對(duì)于C截面不用斷筋；7 03對(duì)于 D 截面，X100% = 68.4%10.28所以10斷5；所以10斷1；所以10斷1；所以10斷2.四.混凝土壓應(yīng)力、鋼筋拉應(yīng)力檢算査規(guī)范 TBIOOO2. 32005 有 n=15E截面：M =426kN m Q = 9.855W “ =0.00643 n = 5× 0.00643 = 0.0964 a =

18、y(np)2 + 2n 一屮=0.353bx(h -x3)2x4816100×2.825×(8-2.8253)= 4.83MP<bJ = & SMPaM _4816Ay (o - %/ 3) " 5.14 X (8 - 2.825 / 3)=132.75MPa < j = 1 SoMPabZ bly -x3)9855 XIO-100x(8 2.825/3)=04MPa< 吟 J = 0.67MPaA截面:M = 14.725W InQ = 38.645kNP = 0.009345n = 5× 0.9345 = 0.14 Ct =

19、 J+2“-n = 0.408X = ahQ = 0.408 ×11 = 4.483Cm2Mj(z0 -x3)2x14725IOO × 4.483 × (11-4.483/3)= 6.9MPa<b = S.5MPaX = ah° = 0.353 ×8 = 2.825。？10.28x(114.483/3)14725=150.69MPdV j = 180MPdQ _38645×10"2" j( -3) " 1×(11 -4.483/3)=0.41MP < % = 0.67MPrtB截面:

20、M = 27.537W mQ = 67.51 IkN“ = 0.00514n = 15× 0.00514 = 0.0771a = Ay(/?/)2+2n/ 一 n = 0.3232M2×27537r 1bx(hQ - x/3)IOOX6.46x(20-6.46/3嚴(yán)兀<匕皿咖X = ah0 = 0.323 × 20 = 6.46c”27537(0-x3) = 10.28x(20-6.46/3) "5(UQMPa < = X*°MPdQ _0_67512x10-bZ " 2( -x3) " l×(20-6

21、.463)=0.38< ,-2 = 0.67MPaC截面:M = 29.965W /HQ = 80.046W“ = 0.00514n = 5× 0.00514 = 0.0771 a =+2zz 一 HP = 0.323X = ah© = 0.323 ×20 = 6.46c/?/2Mbx(h0-x3)2 X 29965IOOX 6.46x(20 6.46/3)=5.20MPa < zJ = S.5MPaM _29965y(0-x3) " 10.28x(20-6.46/3)=16333MPa < = 180MPd咕茅宀TKXzd 嚴(yán)礙VGH

22、.67啄D截面：M = 12.25 kN m0 = 51.226W/ = 0.00841/?/ = 15×0.00841 = 0.1262a =' +2n -n = 0.392X = ah0 = 0.392 ×11 = 4.3 Ic/?= 5.95MPa <b = S.5MPa2M _2x12251“ 一加(兒x/3) 一 IOOX4.31x(l 1 4.31/3)M4（幾一燈3）122519.252x(11-4.31/3)=138.46< = 180MPGQ _ Q?Zb(J _ X / 3)51226x10-100x(114.31/3)=0.54MP

23、a < 匕 = 0.67MPa經(jīng)檢算，各控制截面的混凝土壓應(yīng)力與主拉應(yīng)力.鋼筋的拉應(yīng)力等均小于其 規(guī)定的容許應(yīng)力，故檢算合格。計(jì)算列表如下：截面M(Nm)Q(N)=Abhonx=ho(cm)C(MPa)S(MPa)tp(MPa)E481698550.006430.09640.3532.8254.83132.750.14009350.140.4084.4836.91150.690.41B27537675120.005140.07710.3236.464.78150.100.38C29965800460.005140.07710.3236.465.20163.330

24、.45D12251512260.008410.12620.3924.315.95138.460.54五.檢算裂縫寬度査規(guī)范 TBIOOO2- 32005 有：叫=0.200/?Wn鋼筋混凝土 T形受彎構(gòu)件截面受拉邊緣的裂縫寬度計(jì)算公式:=K K、廣魚（80 + 孚竺）（"） 耳 ½其中：& 一鋼筋表面形狀影響系數(shù)。對(duì)于螺紋鋼筋Kl=O.8；K,=l + 邑+ 0.5 邑-M MM1-S載引起的彎矩；M2-fi載作用引起的彎矩。M 全部計(jì)算荷載作用引起的總彎矩系數(shù)，對(duì)光面鋼筋取0.5,對(duì)帶肋鋼筋取0.3 （該處取0.3）r一一中性軸至受拉邊緣的距離與中性軸至受拉鋼筋重

25、心的距離之 比，對(duì)梁和板，r可分別釆用1.1和1. 2；為受拉鋼筋的直徑6 受拉鋼筋重心處鋼筋應(yīng)力ES 鋼筋的彈性模量，取ES =200×lO3MPa“:一受拉鋼筋有的效配筋率，“廣（必+彎+S九,其中：Ahl、“2、心單根、兩根一束、三根一束的受拉鋼筋 根數(shù)；A、02、03考慮成束鋼筋的系數(shù)，對(duì)單根鋼筋 0產(chǎn)10,兩根一束02=0.85,三根一束 0產(chǎn)0. 70板中均為單根鋼筋，徑加=啟Alli IabE截面 z- AsE5 14=0.006425a一受拉鋼筋里心至混凝土邊緣的距離Iab 2×4×100“ 1 CaMl CVM= I nQ 2997 ” 1819

26、 I QQKl = 1 + 0.3 +0.5 = l + 0.3×+ 0.5×= 1.38M M48164816Q =KKj空(80 + 8+胃)= 0.8×1.38×1.2× ®75 (SO + 8 + (4×12 = f 1 ES 販2×1O30.006425L 7A截面/.=仏=-=0.012854 Iab 2×4×1"1 cqM】 CVMJ75587167Kr = 1 + 0.3 +0.5- = 1 + 0.3×0.5 ×= 1.397M M14725147

27、25 =KAJ且(80 + % + (IM) = O$X1.397X1.2X M(80 + 羅W) = 0.186/;WH<t f62×1030.01285L /JB截面位=1()3 = OO12854 Iab 2×4×1r, = l + 03 + 0.5 = 1 + 0.3+ 0.5×-1- = 1.382 M M2753927539兮=KK空(80 + s + jdf) = 0.8×1.382×I.2× M 叭(80 + 號(hào)°"亡)=0.1 S3mm < ZES 灰200x10'0

28、.01285C截面“=出=“ = 0.012854 Iab 2×4×1 = 1 + 03 + 0.5 = 1 + 0.3+ 0.5×- = 1.3269 M M29965299656yz =f1Xr-(80+8 + °zkz) = 0.8×1.3269×1.2×200Xl(T 0.01285LD截面ZA- 4DQ 252= 0.01157Iab 2×4×100“1 CQMl1 no l°620 n .1631 I QoAAKl = 1 + 0.3 +0.5 = 1 + 0.3×+ 0.

29、5 ×= 1.3266-M M1225112251= KlK“ .(80+s + °4" ) = 0.8×l.3266 ×1.2× 肌巴(80 +，4><12) = 0.199nm <EX200 × IO30.01157計(jì)算列表如下:截面KIMXM2MK2At供, (MPa)UZf(mm)E0.82997181948161. 385.14132. 750.00650.199A0.875587167147251.39710. 28150. 690. 012850. 186B0.8162291131027539

30、L 3810. 28150.100. 012850. 183C0.8259284037299651.32710. 28163. 330. 012850. 191D0.8106201631122511.3279. 25213& 460.011570. 167根據(jù)計(jì)算，裂縫寬度滿足要求?；旌熗琳n程設(shè)計(jì)第二部分、主梁的計(jì)算（取一片梁進(jìn)行計(jì)算）一、荷載與內(nèi)力1、恒載（1）道磴、線路設(shè)備、人行道板、欄桿托架重s=1.76KN/也(2)主梁自重山A5 =586.05(cw2)A7 =30 X190 = 570O(C加 2)(15 + 35)x20 =乜210x10 + 10xx9A)=(190-2

31、4-35)x10 +旦=1376.665(c,n2)2Af =A + A5 +A7 +2人=3062.5 + 586.05 + 5700+1000=10348.55(cn)=A1,+2A)=IO34&55 +2 x 1376.665 = 13101.88(S,)込窄=AVre =10348.55 ×10"4 ×25 = 25.87 l(7Vm)g； = 13101.88 × 1 O'4 × 25 = 32.755（KTV /In）設(shè)寬段長(zhǎng)度為4.25x2m,窄段長(zhǎng)度為8m,截面在距支座4. 25m （即L/4處）發(fā)生 突變（由5

32、0Cm變?yōu)?0Cnl）O則（長(zhǎng)度L取為16. 5m）=29 An(KN m)§2寬 1 寬 +§2和乍 _ 8× 25.871 +8.5 x 32.755L _165q = ql+q2 = 19.6 + 29.417 = 49.107 (Zn)在計(jì)算出q之后，相當(dāng)于整個(gè)計(jì)算跨度16m上均布有大小為49.107KNm的 力，按簡(jiǎn)支梁進(jìn)行處理。(兩旁的0 25m可以近似忽略)支點(diǎn)處：0=49.107 X16 / 2 = 392.136JwVMo= OkN mL/8 處：Glz8=Co-/8x = 0.375x49.107x16 = 294.1°2RNMUS

33、=Q)Z 8 - g(L / 8)2 / 2 = 0.0546875 ×49.107×162 = 686.238kN mL/4處(變截面處)：18混礙土課程設(shè)計(jì)0“ = Q廠厶 / 4 Xg = O.25 X 49.107 X16 = 196.068WM UA =QQL4-q(L4)h2 = 0.09375 ×49.107× 162 = 1176.408kN m3L/8 處：QM 用=a-3L8×t/= 0.125×49.107×16 = 98.034WM3LZS = Qj 3L8-t(38)2/2 = 0.1171875&

34、#215;49.107×256 = 1470.5IQV mL/2 處：Qu2 =Qo-Ldxq = OkNMul =QQL/2-(I(Ll 2)2/2 = 0.125×49.107×162 = 1568.54W m計(jì)算結(jié)果列表如下:截面支點(diǎn)L/8L/4 (變截 面處)3L/8L/2Qi (kN)392.136294.102196.0689& 0340M (kN m)0.0686. 2381176. 4081470. 511568. 542活載(普通中活載)沖擊系數(shù)：1 + = 1 + 2.0x() = 1 + 2.0x() = 1.26130 + L30

35、+ 16其中 6z = 4(1-)2h=0.5m a = 2h=0.5m為梁頂填土厚度，L為梁的計(jì)算跨度。此外，該粱由兩片梁并成，因此 每一片梁還要乘以1/2。綜上可得，活載作用下的內(nèi)力計(jì)算公式為：SmaX=Ia÷)S影響線的面積；K通過結(jié)構(gòu)力學(xué)課本表11-1 (中-一活載的換算荷載)可得到。支點(diǎn)處：L = 6m t = 0 Ko=I37.7KN/m支點(diǎn)M L. C. Mo= £(1 +“)0 = 019L = I6W 4×16×1=8 KfKN葉支點(diǎn)Q L. C.1混礙土課程設(shè)計(jì)L/8 處M L. C.7/8L/8 處Q L.C. 1/8LzWM L.

36、 C.3/43L/4處Q L. C.'1/44Q)=丄X 1.261x137.7x8 = 694.56( KN)2L/8 處：L = 16/7? C =丄× 16× 1.75 = 14 Kw = 125.5KNIm2 %MX =(1 + /) =丄X1.261 × 125.5x14 = 1107 .79(KN/加) 8 2 2L = 14m = X 14×0.875 = 6.1252KK =143.3KN/加Q =1×1.261 ×143.3× 6.125 = 553.40(KN) i 21/4L處(變截面處)：L

37、= 16 = -×16×3 = 24 K17 =123.8KNm2 %MI =y(l + ) = × 1.261 × 123.8 x 24 = 1873 .34( KN / m)L = 12m = -×12×0.75 = 4.5 KL=I50AKN/m2 %Q =丄X 1.261 X150.4x4.5 = 426.72(KN)Z 23/8L 處：L = 6m = 16×=30K%=121.9KN/加M3 =(1 + /) =丄× 1.261 × 121.9 x 30 = 2305 74(KN/m) 2 2

38、 = 10 = ×16× = 325 K% =159.8KN/加Q3 =-×1.261×159.8×3.125 =314.86(KN)8 21/2L 處：L = 6m G =丄X 16x4 = 32K17 =9AKNm2 %KMX = (1 + /) = -× 1.261 × 119.4× 32 = 2409 .0(KN/m)L V處HL C亍 22一LzWQ L. C.1/220混簾土課程設(shè)計(jì)L = Sfn = ×05×8 = 2K%=1722KNznII =1×1.261 

39、5;172.2×2 = 2174(KN)計(jì)算結(jié)果列表如下:截面支點(diǎn)L/8L/4 （變截 面處）3L/8L/2Km)O2468IU137.7143.3150.4159.8172.2KM137.7125.5123.8121.9119.4Qs (kN)694. 56553.40426. 72314. 86217.14Mffi (kN m)O1107. 791873. 342305. 742409. Ol二、主拉應(yīng)力驗(yàn)算:21取 = ISnUn,則o = h-a = 182.5CmZ = 0.920在L/4 (變截面處入3L/8、L/2處b = 30Cm在支點(diǎn)L/8處 h = 50Cm支點(diǎn)處

40、：b* =P = 一一 =1°867°XloT = I .29MPa < SJ = I .80MPdJ bZ 0.92©0.92×0.5×1.825TL/8 處：6=2 = _Q-_ =l(' = l01MPGVbm J = l80MPd、bZ O.92o?0.92 ×0.5×l .825"QQ622.79bZ0.92Z?0.92 ×0.5 × 1.825Q _ Q 622.79L/4處（變截面處人IO"3 = 0.14MPa < 1J = 1.80MbZ 0.92

41、兒b 0.92×0.3×1.825一 124MP" <5 -1.80MP"混礙土課程設(shè)計(jì)3L/8 處:bZ 0.92412.890.92×0.3×1.825X 1(T' = 0.82MP" v f.1 = 1.8027L/2 處:Q _ Q bZ O.92zoZ?217.140.92×0.3×1.825x IO- = 0.43MPd < 7,.1 = 1.8OMPrt數(shù)據(jù)列表如下:截面支點(diǎn)L/8L/4 （變截 面處）3L/8L/2a (cm)7.57.57.57.57.5b(cm)50

42、50303030h0182.5182.5182.5182.5182.5控制Q1086. 70847. 50622. 79412.89217.14O ZI1.291.011.240. 820. 43三、跨中主筋設(shè)計(jì):取 a = 1.5ClnA0 = 190 7.5 = 182.5cz? Z = O.92o取HRB33520的鋼筋，則單根鋼筋的面積為:AI=JX2-3.1WAI131.613.14= 41.9取” =44所以 A、=九 X 45 = 34 X 44 = 138.16(C)査規(guī)范 TBIOOO2 3-2005 有：受拉區(qū)域的鋼筋可以單根或兩至三根成束布置，鋼筋的凈距不得小于鋼筋的 直徑（對(duì)帶肋鋼筋為計(jì)算直徑），并不得小于30mu當(dāng)鋼筋（包括成束鋼筋）層 數(shù)等于或多于三層時(shí)，其凈距橫向不得小于1. 5倍的鋼筋直徑并不得小于45mm,豎向仍不得小于鋼筋直徑并不得小于30mm。（對(duì)于螺紋鋼筋應(yīng)考慮外側(cè)螺紋帶來(lái) 的影響,計(jì)算時(shí)采用外徑進(jìn)行處理,例如本設(shè)計(jì)中20的螺紋鋼筋外徑為22）o 因此得到鋼筋布置如下圖：四、跨中截面應(yīng)力驗(yàn)算：rt=14×4.5 + 7×(4.5 + 1.91) + 14×(4.5 +1.91 + 5.2) + 7x(4