25米装配式预应力砼简支T形梁桥设计计算

1、桥面板内力计算 (2)1.1恒载及其内力 ()2 1.3荷载组合 ()3 2.2.1用“杠杆法”计算荷载位于支点处各主梁的荷载横向分布系数 ()52.2.2用“修正刚性横梁法”计算荷载位于跨中时各主梁的荷载横向分布系数(6) 3.1用“刚性横梁法”或按“梁系法”计算横梁内力 (21) 25米装配式预应力砼简支T形梁桥设计计算计原始资料jm 3.上部结构主梁布置图：(单位：cm)T|KO|ao|iSii&a逊—-1—-JJLj1■1 2布系数或用“比拟正。(1)每延米板上的恒载g：混凝土垫层g1=0.1175X1.0X25=2.94kN/m20.181.026=3.64kN/m合计:gi6.58kN/ml剪力Qsg=glo=6.58x0.71=4.67kNI16.580.712kN.ma1=a2+2H=0.20+2XP=140kN，车轮着地长度a2=0.20m和宽度0.1175=0.435mb1=b2+H=0.60+1X悬臂板根部的有效分布宽度均为a=a+d+2l0=0.435+1.40+2x0.71=3.255m冲击系数卩=0.3矩用简化方法计算Msq(1)2£(lc4a…2b1)4 207175(0.71-------)14.82kN.m4用简化方法计算荷载集度(前后轮重叠)PP2^214023.2550.7175N不考虑铰剪力的影响，按自由悬臂板计算，各板承担其上的荷载，则自由悬臂板根当桥面板按承载能力极限状态设计时，一般应采用基本组合，并根据《公路桥涵设cMudMsg4Msq)=1.0X(1.2X(-1.66)+1.4X(-14.82))=-22.74kN.moQud0(1.2Qsg1.4Qsq)=1.0X(1.2X4.67+1.4X55.33)gg.07kN有了控制设计的计算内力，就可按钢筋混凝土板截面设计方法来设计板内的钢筋和进行_______Q________________1GOO.18主梁g,0.181.620.100.181.60.18--------------260.15522对于中梁g221.112.22kN/mg3丄0.0650.17142594.75k^mg45291.11kN/mggi.1119.45kN'mg'gi12.661.112.224.571.1120.56kNm桥面铺装层道»c“口262612.66kNm“对于边梁2弯矩(KN/rr)剪力(KN剪力(KN00002活载内力计算喻口口 位于支点处各主梁的荷载横向分布系数只需要算出1、2、3、4、5号梁支点截面的荷载横向分布系数即可，用杠杆法的原理绘制出1、2、3、4、5号梁的荷载反力影响线，分别入下图(b)、(c)、 (d)、 (e)、(f)。2)应用《结构力学》原理，确定荷载在横向最不利位置，分别如上图所示3)内插计算对应于荷载位置的影响线纵坐标对于汽车荷载：轮重=1/2轴重汽车荷载的横向分布系数moq丄iq2qkNm单侧人行道宽，其分布系数为人群荷载重心位置的荷载横向分布影响线坐标morr00012345梁法”计算荷载位于跨中时各主梁的荷载横向分布系数.0aia1.622主梁细部尺寸(单位:cm)1.6321.62221.60A、求主梁截面的重心位置yi818140.514181460.5146一141814659.2cmC:22扭刚度系数.30.270.80.171.70.189.60.209.40.250.20.29110.141.90.155.50.229.10.312<0.1bcTt1/b|t2/b213t1/b1t2/b214/1580.0890.1,故查表2-2得c1/318/1460.1510.1,故查表2-2得C21/31430.302146183451653.5893cm414/1400.1,故查表2-2得c0.3120.2550.033lT0.11401430.305160183492174.2533cm4取两者中较大的一个，故lT492174.2533cm4而n=9;G=0.425E;L=24.95m因次有GlI"1n—aiTi11,C25E24.54921742533E2)计算荷载横向影响线竖标——---------------------------------2299a2299a961a961a22ia2960.145a2960.1451aai22a222ia2i2?a2?2ia2i1-0.96910.96910.9690.175a2i10.9690.175a2ia22aa2丄0.96空—0.047a29153.6ia1921960196aiai2a961.62a960.09446i46ina9153.692192'0.111.96'0.111.96153.6B荷载在横向最不利位置，分别如下图所示。对于汽车荷载：轮重=1/2轴重汽车荷载的横向分布系数m°q丄iq2qkNm单侧人行道宽，其分布系数为人群荷载重心位置的荷载横向分布影响线坐标morr梁号荷载分类支点Mo跨中Me汽车0.5310.6331人群1.6090.406汽车0.50.5722人群00.332汽车0.5940.53人群00.259汽车0.5940.4824人群00.222汽车0.5940.4445人群00.22200、——‘工.097C1184号聖一士舊、尸心\一-<J.3371-------------------------------------------------------------------------------------0.Ill1)主梁跨中截面弯矩计算主梁弯矩时，对跨中的荷载横向分布系数与跨内其他各点上的荷载横向分布系数是采用相同的值，这是实用方法基本原理的前提所决定的。目前在实用计算中，全跨采me响线和设计荷击系数，按《公路桥涵通用设计规范》得110.345-nJr1t4IMi«i\titiitif6.x中弯矩计算公路-II级车道荷载(max):kP0.7518036018024.55193.5kNk505124.502450275m24将以上数据代入式(2.2.43)得1.150.670.633(7.87575866.11kN.m193.56.125)0.4060.753.5124.502mcrqr8279.96kN.m2公路-II级车道荷载:M]qd)Z1.150.670.572(7.87575193.56.125)782.65kN.mM1mcrqrr20.3320.753.524.50265.39kN.mMi(1)(mqkmRyQ2q21.150.670.520(7.87575193.56.125)711.50kN.mMmcrqrr210.2590.753.5224.50850.78kN.mM1(1)(mqkmRyQ1.151.150.670.482(7.87575193.56.125)659.50kN.mMmcrqrr21843.72kN.mqM1(1)(mqkmRyJq21.150.670.444(7.87575607.51kN.m193.56.125)M1mcrqr_r2.2220.7543.72kN.m4.50281◎:JLn1tMM1it<----------------*L.公路-II级车道荷载:AiM1q4q(1)(mqk1.150.670.633649.88kN.mM14crrmcrrr0.4060.753.559.97kN.mmqkmqk4q41.150.670.520533.7kN.mM1mcrqrr40.2590.753.538.26kN.m4.594m面积1224.504.59456.27m2193.54.594)193.54.594)(7.87556.2756.27193.54.594)193.54.594)(7.87556.2756.27公路-II级车道荷载:M14q4 (1)(mqk1.150.670.572mcrqrr40.3320.753.549.04kN.myQ(7.87556.27193.54.594)587.07kN.m56.2741.1541.150.670.482)mqkmPkyk)(7.87556.27193.54.594)494.70kN.mM1r4mcrqr0.2220.753.556.2732.79kN.mM14q4mPkyk))mPkyk)1.150.670.444(7.87556.27455.70kN.m193.54.594)crrmcrrr40.2220.753.556.2732.79kN.m44)支点处剪力1号梁跨端的设汁荷载剪力计算；图2-4a)为主梁纵断面图，图2-4b)为荷载横向分布系数沿跨长分布图；图2-4c)为跨端截面剪力影响线图；计算剪力时，为了得到最大剪根据这条曲线布置最不利荷载(图2-4d)。严格来说，最不利荷载位置应通过求函数极值因极值附近的函数值相差甚小，故可直接将重轮布置在t1ktdI-1d--------_~~~——__16.1257.293m3)Qoq(110.4750.5312757.293232.20.531人群荷载:」■0^0451.6096-125103045佩375咧亦Qorqr0.753.58.48122.26kN0,50,5iTrmm104290518.3750.42926.12526.648m2222(1)1.150.677.8756.648232.20.5N12qr0.753.53.053.05m28.007kN3-18.3750.390.390.5946.1256.462m22FTST.0.1&7(1)1.150.677.8756.46223220.594面积1-24.50.19422.377m2Qorqr0.753.52.3776.238kN-1E-18.3750.36203620.5946.1256.126m222Qoq(1)mipiyiQ1.150.677.8756.126232.20.594荷载：面积—24.50.16722.04m2Qorqr0.753.52.045.34kNI^IlHll0.4441~~-------------1<11I4f1i1»1H34t1■■Uh.-——---------------------L—-----0.333—III/IF0.167ir*车道荷载：面积丄18.3750.3330.3330.5946.1255.898m222Qoq(1)1.150.677.8755.898232.20.594荷载：面积2QQqr0.753.52.045.34kN25)跨中剪力计算1■!■F1J1t«JJ<r11耳(]0.51»*4*・■09Q12q2Q1-r21.150.670.753.50.633-2147.875丄12.254KNQ1罗Q1-r1.150.670.753.50.572-21-12.25440.3322.67KN41232.27.875-12.254178KN1r20.753.5140.2592.08KNQ1q21.150.672474KN人群荷载:Q1r20.753.51412.250.2221.78KNQ121.150.672.254人群荷载:Q1r20.753.51412.250.2221.78KN6)L/4截面处剪力4q413r40.753.518.3750.406r424N141.150.670.5723N144q13r0.753.518.375r244车道荷载:Qq车道荷载:Qq4十123418.3750.2594.68KN34q484.831KN4Q0.753.518.3750.2224.02KNr2443Q0.753.518.3750.2224.02KNr24422232223内力计算荷载跨中横隔梁的最不利荷载布置如图3-2所示131311Pgpiyi(0.752381.00.7510.5—1.02)%%-”閒z7umnrroA十图3-2跨中横隔梁的受载图式横隔梁的内力影响线1号梁的横向影响线竖坐标值为:2a2 220.3781