【《某跨海大桥3×30米预应力连续梁桥预应力钢束的设计计算案例》2500字】

某跨海大桥3×30米预应力连续梁桥预应力钢束的设计计算案例目录TOC\o"1-3"\h\u23965某跨海大桥3×30米预应力连续梁桥预应力钢束的设计计算案例 1308261.1预应力钢束面积的估算 1265321.2预应力钢束的布置 3119721.2.1预应力钢束的布置原则 3245581.2.2预应力钢束的布置 3107521.3模拟预应力钢束 680731.4钢束的预应力损失 8159711.5预应力次内力计算 11131631.6普通钢筋的配置 111.1预应力钢束面积的估算在分析Midas桥梁模型的基础上，确定了PSC设计参数、设计材料、输出位置和裂缝宽度系数，并进行了设计梁的设计。在结果栏上，可以看到预应力筋的估算。其结果是截面上下边缘的最小配束。控制部分预应力筋的估计数量见表1.1。表1.1控制截面预应力钢筋量估算单元位置顶/底Mg1(kN·m)Msum(kN·m)Mj(kN·m)ey(m)Ny(kN)Ay(m^2)1J[2]底-18.3910-24.8038-24.8038-0.53850.00000.00001J[2]顶-1584.8423-311.0632-1934.79740.20291896.86010.00159J[10]底14087.099520796.631625678.9520-0.766825171.45790.02039J[10]顶61.265711961.4960-3316.90720.45223251.87170.002716J[17]底14691.080723187.983328348.6424-0.842627792.81940.022416J[17]顶-79.380610660.2327413.85830.44960.00000.000023J[24]底4737.896411904.565814004.3100-0.794313729.73190.011123J[24]顶48.6980-1136.3602-2609.93900.29142558.76670.002032J[33]底-182.7061-8503.25734301.7449-0.82484217.39700.003432J[33]顶-14069.2737-23180.9692-27449.74860.428526911.51830.021739J[40]底1868.247910263.433711721.4429-0.835311491.62420.009339J[40]顶-88.4357-5591.3959-6392.92110.23386267.57710.005147J[48]底7318.176117281.470120460.6407-0.852520059.47530.016247J[48]顶-668.4703524.8292-6.45060.45246.32410.000054J[55]底187.91328138.69819079.3134-0.77959299.61350.007554J[55]顶-1679.3990-7352.3484-8184.52760.34338024.05610.006561J[62]底-413.3815-10950.9543533.6606-0.8248523.19660.000461J[62]顶-16642.7778-26083.4350-31001.76120.429230397.80520.024670J[71]底6846.587114361.901617100.0753-0.835516764.79950.013670J[71]顶-18.10581241.1026-3718.93510.44953646.01910.003078J[79]底15666.927324041.860829504.9904-0.842628926.49520.023478J[79]顶-72.419212168.6544-422.90840.4496414.61660.000384J[85]底12869.139918884.486023339.9683-0.830322882.32180.018584J[85]顶-21.837511079.7264139.73390.27530.00000.000092I[92]底-18.3910-24.8214-24.8214-0.53950.00000.000092I[92]顶-1666.4330-311.0809-1911.29190.20211877.73720.00151,9,16和23单元在支座的左侧，1/4L，1/2L，3/4L;32,39,47,54,61单元在支座的中间，1/4L，1/2L，3/4L;70,78,84,92位，右跨度1/4L，1/2L，3/4L和支撑。预应力钢筋的最大面积出现在61单元，所需面积为0.0246m²，预应力钢筋的最大面积出现在78单元，所需面积为0.0234m²。根据预应力筋的估算形式，所需钢筋的最大面积为0.0246m²。因此，在桥梁设计中共有20根预应力钢筋，分为上板预应力钢筋、下板预应力钢筋和腹板预应力钢筋三组。该桥采用高强度低松弛钢绞线strand1860，直径为11.2mm，标准强度为1860Mpa，锚杆下的张拉控制应力为1395Mpa。该桥由20根预应力钢绞线组成，按形状分为T1、T2、T3、B1、B2、B3、F1、F2和F3。每股由19股组成，每股12股，剩下的两捆，每捆由12股组成。钢梁波纹管为90毫米，如图1.1所示，用于总结预应力钢结构。编号下料钢绞线规格（mm）单根长（mm）束数总长（m）总重（kg）T112-φ11.2387762698.0768.5T212-φ11.2478352861.0948.0T312-φ11.2387762698.0768.5F119-φ11.27946123019.53324.4F219-φ11.28354323174.63491.3F319-φ11.28761123329.33661.5B112-φ11.28585244120.94537.1B212-φ11.26638421194.41311.0B312-φ11.26638421194.41311.0图1.1预应力钢束工程数量汇总1.2预应力钢束的布置1.2.1预应力钢束的布置原则预应力的重心线要在束界范围内；锚具类型要与预应力钢束适合；预应力钢梁布置既要满足结构受力要求，又要满足次内力要求；预应力钢绞线的布置应考虑材料的经济因素和施工技术条件；。布置预应力钢束时要尽量对称；预应力钢梁分层布置时，应在靠近横截面顶板或底板的一侧布置较长的梁，而较短的梁应在远离横截面顶板或底板的一侧布置预应力钢索分层布置时，应先将下部预应力钢索锚固，然后再将上部预应力钢索锚固。1.2.2预应力钢束的布置该桥的预应力钢束由直线和圆弧组成，半径为8米。在桥的左侧，安装顶板预应力筋T1和底板预应力筋B2。在桥梁右侧，顶板预应力筋T3与底板预应力筋B3对称布置。中跨设置顶板预应力钢梁T2、腹部预应力钢梁F1、F2、F3和底板预应力钢梁B1。横梁在横截面上对称布置。例如，图1.2显示了预应力钢绞线的纵向布置，图1.3显示了预应力钢绞线的横截面，表1.2显示了预应力钢绞线的结构。图1.2预应力钢束纵向布置图图1.3预应力钢束横截面图表1.2预应力钢束配置表单元截面上缘（根）截面下缘（根）1229410162122341232104394124721254412611067041078210844892221,9,16和23单元在支座的左侧，1/4L，1/2L，3/4L;32,39,47,54,61单元在支座的中间，1/4L，1/2L，3/4L;70,78,84,92位，右跨度1/4L，1/2L，3/4L和支撑。1.3模拟预应力钢束预应力钢梁共20根，分为上预应力钢梁、下预应力钢梁和腹板预应力钢梁。首先定义预应力钢束的特征值，然后利用该特征值选取预应力钢束的相应特征值，引入水平和垂直弯曲图形生成mct文件，通过操作文件将钢束插入梁体，调整预应力钢束的插入点和分布单元，使20根钢梁依次插入箱梁的合适位置。图1.4显示了钢梁的特点，图1.5显示了G钢束的排列，图1.6显示了钢梁的形状。图1.4钢束特性值图1.5布置钢束图1.6钢束的形状1.4钢束的预应力损失在预应力混凝土桥的设计中，所需的预应力通常取决于桥梁所承受的荷载大小。但往往是由于预应力钢筋与管壁之间的摩擦、锚固变形、收缩和节点压缩、预应力钢筋与支座之间的温差、混凝土的弹性压缩、预应力钢筋的应力松弛、混凝土的收缩和徐变使实际预应力小于张拉控制应力，二者之间的差别就是预应力损失。即张拉控制应力，即预应力损失。在设计这类构件时，必须考虑预应力损失，使预应力尺寸满足荷载尺寸要求，因此必须对钢梁的预应力损失进行计算。Midas可以在结果柱的结果表中选择预应力损失，然后我们可以看到钢束在某一施工阶段的预应力损失，表1.3。表1.3T1的预应力损失单元应力(考虑瞬时损失)弹性变形损失:B(kN/m^2)比值(A+B)/A徐变/收缩损失(kN/m^2)松弛损失(kN/m^2)应力(考虑所有损失)/应力(考虑瞬时损失)端部有效钢束数:A(kN/m^2)钢束组T1阶段桥面铺装11173210.9423461.55841.0004-4397.3487-21517.62170.9783221173210.9423467.10041.0004-4397.6447-21517.62170.9783231180571.8432290.23061.0002-6174.2765-22308.45550.9761241189718.2571-241.18220.9998-7777.5900-23302.51430.9737251198804.2919-831.92630.9993-15169.3192-24302.51310.9664261213587.4760-2038.42140.9983-16616.6066-25956.16390.9633271232383.2954-2722.97120.9978-19644.2164-28106.30070.9591281241157.3868-3508.87120.9972-18296.7039-29128.26390.9590291249873.7598-3912.20150.9969-21693.2444-30151.00960.95542101260688.6433-4563.27610.9964-21011.7473-31444.89070.95482111271414.6661-4927.08330.9961-21721.9247-32741.61060.95332121279931.9932-5122.71930.9960-22309.6081-33783.68010.95222131277788.3686-5212.99190.9959-23059.1259-33520.38280.95172141269382.7198-5211.01330.9959-23559.4265-32494.62570.95182151261032.3670-5122.01930.9959-23961.4445-31486.17590.95202161250671.6363-4869.58960.9961-24237.1652-30249.56850.95262171244496.1065-4648.90000.9963-24260.4291-29520.19360.95312181236309.4695-4272.46720.9966-24120.4279-28562.16580.95402191228176.6752-3801.07360.9969-23886.7314-27620.45530.95502201220097.3947-3231.76270.9974-23442.8473-26694.82630.95632211212071.2548-2571.49280.9979-22901.2674-25781.04080.95772221206847.3172-1819.82020.9985-22151.6185-25198.11660.95932231214838.8602-953.45520.9992-21491.5945-26097.65830.96012241222883.3268211.22311.0002-23942.4972-27012.89260.95852251230981.05501438.96341.0012-25491.0374-27944.05160.95782261239132.41692840.69451.0023-27923.6597-28891.37390.95652271247337.73874210.63581.0034-28864.2477-29851.09600.95632281251047.84154790.16761.0038-27566.0537-30294.18700.95762291259332.08115916.13731.0047-26284.5528-31282.12660.95902301243727.67188276.29251.0066-21874.3333-29429.83860.96542311243727.67188241.50481.0066-18149.2437-29429.83860.96842321236967.74219306.74511.0075-16698.7918-28638.82510.97092331230172.02328431.01711.0068-24147.3061-27850.57590.96462331221626.76656784.06081.0055-24367.2648-26869.28770.96362341221626.76656751.84141.0055-24310.5447-26869.28770.96372351213024.93455231.15121.0043-23119.9670-25892.