上部结构计算

1、上部结构计算3. 1加劲肋刚度验算加劲肋刚度和临界钢度（底板加劲肋）Q345 钢材的各项指标：E = 210xl09Pt/, u = 0.3被加劲肋的抗弯钢度D = 一岂一厂=11077 x IO'”" 亦12（1 ）被加劲板用度t二15mm单根加劲肋对被加劲板的抗弯惯矩I =J_xl6x 2003 + 16x200xl002 =4.26x107 mm41 12. hi I. El. 210 x 10u Pa x4.26 x 10 nvn4 “亠 ， 加劲肋的刚度比r= =5 =80762 mm2D 11077 x10"“"/加劲板的临界长宽比绳=#1 +

2、 “，“ =坷+1 = 4 +1 = 5其中一被加劲板分隔的局部板件数口料=坷+1m纵向加劲数Ua0 = V1 +5x80762 = 25.2纵向加劲肋实际长宽比“ =200 一 16 = 12.5 <a0 （满足）因为加劲肋是等强度均匀布置的，且“<绳，所以临界刚度比"4血（1 +词）空也n式中a 加劲板的长宽比a = a/ba加劲板的长度（横向加劲肋间距）b加劲板的宽（腹板间距）一单根加劲肋的截面面积与被加劲板的面积之比=A,/ht 人一单根加劲肋的截面面积J. = A/bt = （16 x 200）/（3300 x 15） = 0.065a 3.3a =0.11b

3、30请预览后下找!r； =4x0.112 x5（l +5x0.065）-（）11, + 1）- = 11578 <r, =80762 （满足）3. 2加劲肋的刚度和面积已所要满足的要求ht3bt4 = 3200 mm2 > =咖"川匚=990mm2 (满足)10/750加劲板的长宽比应力计算：(10米范围内)假 设 人 行 荷 载 2/, 桥 面 板 自 重G = 30000 nun x3300nmi x5mm x7.Sg/cmy = 11.583 = t ,纵向加劲肋自重G =1(35 + 20)x30 一丄(32.6 +17.6) x 28.8 x 1000x 7.8

4、 x 16 = 12.11 2 2横向加劲肋自重 G3 =2 x 25x1200 x 7.8 x 9 = 4.2/则在10长的一段整个最大荷载为G = 74 + 24.34/+ 12.7/+4.2/= 115.24/1米长的一段最大荷载为G = 115.24*10 = 11.524/ ,对一个腹板的荷载G = 11.5244-2 + 2 = 7.762/被压板的面积 A = 1000mmx20m/n = 20000n/n2cr.=-="力,=3.88N/mm2 A 2000伽广腹板自重 G = 100 x 2x 100x 7.8 = 0.493/“ =(0493/ + 7762f)/

5、20000 曲3 =4.1287V/n/n20 = (bb2)/b =(4 1283.881 )/428 =0.06f = 0.650? +0.134-1.0 = 1.0101不设加劲肋的最小板厚 5 = b/(24M)= 6000 /(24 x 1.0101 x 10) = 24.7mm因为所以r, “= 4a%(l + n6)(-)2 -= 4x0.1672 xl6(l + 16 x 0.022)(-)2 -"7+l广=2.35 tn2616请预览后下找!普警=咋儿號琴“9.3W加横向加劲肋的刚度Irlrrq （不满足）所以一12-1 = 26901G网=厶2" +昭）

6、（勺）一12-1=丄2x256x（1 + 16x0.022）（寥尸6000 x 263Hx 26901 =24.7xlO,033最小板厚及极限强度讣算 t = b/(48 fn) = 6000/(48 xl.0101xl6)= 7.7mm应力计算I,. = £ x 16mm x (200")' +16mm x 200” x (100/?/?)2 = 4.26 x 10 mm4I =君x20”x(250mm)' + 20mmx250mmx(125mm)2 = 10.4xlO12(1-12(1-0.3)-x4 26x1q7=357 b 1 400 x26 s12

7、(l u)S 12(1 0.3)2 1A/1 in7 “r =一If = xl0.4xl0 =34bf 1000x26af() = #(l + “)/l + (l + q); = #(1 + 16x35)/I+ (1 + 80)x34 = 0.67换算压杆长细比 / = imx(=】mx( 1000,671) = 1000 mm换算压柱有效截面回转半径心=希171T,1 口 I 1345 xlO6 1000八小& = 、 =yt x= 0 0.27r E rxe 3.14 V210xl0'116则如=1, o- =o- = 345x106P«b请预览后下找!R. =

8、0.562、咗如=0.562竺傅 x 型=0.35eV E tY 210x10"26¥ = 0.702心 1.640疋 + 0.654© + 0.926 = 0.986bc. = 400 x 0.986 = 394 nun令 =394"”X 394 =113人 3.14 V 210则 = i , b湘=345x1(/只(收敛)6 _如讨+4 J hrt + As= 0.988f _394x26 + 16x200 345x106_ 400x 26+16x 200 X 345x 106则 q = 0.988 x 345xl06 Pa = 341x 106 P

9、a34横隔版最大间距和刚度（1）横隔板最小刚度计算箱梁上顶板的截面面积耳=8000 x 24 +15 x 10714 = 2991 cm2箱梁下底版的截面面积F, =6000 x 24 + 9x16 x 200 =1728 cm1一个腹板的截面面积你=100（/10 x20 = 632c Fmm顶板对箱梁对称轴的惯性矩1和=丄X 26x （8000）' =1. lx 212底版对箱梁对称轴的惯性矩I广丄X26X60003 =0.47x112腹板长度 H = 1000 yj'iOmm1乞+2坊Cbt 12fh =470x10960008000+1200012x 63246 = 1

10、77曲HOOxlO980002x8000+600012x 63246=247(7 泸请预览后下找!化（l + ¥），+a巧（1 +単尸+2耳（才一即，+Q；）=20.4x10%汩焉X呼-起X譽曲丽沁曲"島yxwoo、仏 7 题WK, = 20卑=20x2.1xlO&x2；.4xl()L =】338x 10i2 = 133&WN md 4400tf(2)实际刚度计算设计为实腹式，如图 2-1, A = -(B!i + B,)H =-(8000+ 6000)x3000 = 2m22 2A' = -(仇 + bt)h = -(6.4 + 4.4)xl.4

11、= 7.56m2', p = = = 0.36<0.422A. 21为实腹式。Q345 钢的剪切模量 G = E/2x(1 + u) = 210 x IO®Pa/2x(1 + 0.3) = 81x 109Pa此时横隔板主要受剪力的影响K = 4G4rD =4x8.lx 105x(798+598)x297 一2x2 = 1343MN 加 >K«满足要求设计为刚架式X型，如图2-2,可得斜撑长度为L, = 7fW+(W = 7.6/n 取斜撑尺寸为760cm x 40cm x 3cm则 A1 = 2x0.4mx 1.6m0.4mx0.4加=5.92/w2 &

12、#171;5.8m2An I"A" = 4一 A = 2nr -5.8/n2 = 15.2m2 p = = = 0.72 <0.8 (不符合) A 21取斜撑尺寸为760cm x 30c? x 3cm则 A = 2xO32x76?-(O32) =4474Am2An i6 9AB = A-A! = 2m2 -4.1m2 = 16.9m2p = =0.805 >0.8 (符合)A 21那么K = 8EA2= 8x210 xlO9x(207306 cm)230 cm x 3cm(760cf= 1480MN?>K满足要求设计钢架为V型，如图2-3,可得斜撑长度为Ld = 7（4）2+（3/h）2 = 5m请预览后下找!设计斜撑丿、)5000/77/77 X 500" X 30/77/77则 A! = 2 x 5mx 0.5m = 5m2 » 4.8m2Aff = A At = 21/m2 4.8m2 = 16.2m2p = = 0.77 (不符合)A 21设计斜撑为 5000/77/77 X 450/77/77 X 30/77/7?贝ij