湘江大桥主桥上部结构计算书090616

湘江大桥主桥湘江大桥主桥预应力混凝土连续梁上部结构计算书工程名称： 湘江大桥主桥预应力混凝土连续梁 工 号： 设计阶段： 施工图设计 计算内容： 上部结构计算 计 算： 2009年 6月校 核： 2009年 6月审 查： 2009年 6月广州瀚阳工程咨询有限公司二九年六月目 录一、结构概况3二、设计采用规范3三、主要技术标准4四、主要材料44.1 混凝土44.2普通钢筋54.3预应力钢材5五、设计参数5六、施工顺序说明6七、模型介绍8八、结果分析98.1施工过程主梁应力98.2正常使用极限状态压应力验算128.3正常使用极限状态抗裂验算168.4承载能力极限状态验算218.5主梁变形2323一、结构概况本桥属于湘江大桥主桥工程，为5跨连续梁，跨径组合为63.5+3122+63.5 m，梁截面为双向横坡截面，采用平均梁高简化计算，关键截面主要构造尺寸如下图：图1.1 跨中截面尺寸（cm）图1.2 中支点截面尺寸（cm）二、设计采用规范公路工程技术标准 JTG B01-2003公路桥涵设计通用规范 JTG D60-2004公路钢筋混凝土及预应力混凝土桥涵设计规范JTGD62-2004公路桥涵地基与基础设计规范 JTGD63-2007公路桥梁抗震设计细则 JTG/T B02-01-2008公路桥涵施工技术规范 JTJ 041-2000公路桥梁抗风设计规范 JTG/T D60-01-2004三、主要技术标准1、设计基准期： 100年2、 主干道计算行车速度：60km/h。3、 荷载标准：采用公路级荷载标准，跨湘江主桥桥面布置双向六车道。人行道人群荷载集度4kN/m2。4、沿线河流通航净空：采用-3级航道标准,净高10m,净宽75m,上底宽56m,侧高6m。5、标准桥宽：跨湘江主桥桥面宽27.5m。由0.25m杆栏+1.5m人行道+0.5m防撞墙+33.75m机动车道车道+0.5m双黄线+33.75m机动车道车道+ 0.5m防撞墙+1.5m人行道+0.25m杆栏组成。6、设计基本风速：27.2m/s（离地10m，频率1%，10分钟平均最大风速）。7、本桥所在地区地震基本烈度为度，防震措施按度考虑。地震动峰值加速度为0.05g，地震动反应谱特征周期为0.35s。8、桥面铺装：9cm沥青混凝土。9、公路桥涵设计安全等级：湘江主桥：一级，桥梁结构的重要性系数为1.1；10、设计洪水频率：跨湘江主桥1/100。11、环境类别：类。四、主要材料混凝土、钢筋及钢绞线等材料的设计抗压（拉）强度、弹性模量等基本力学性能及参数均按相关规范取值。4.1 混凝土混凝土设计参数取值见下表：表4.1 混凝土材料参数混凝土标号C55弹性模量E（MPa）35500剪切模量G（MPa）14200泊桑比0.2轴心抗压设计强度fcd（MPa）24.4轴心抗拉设计强度ftd（MPa）1.89线膨胀系数0.000014.2普通钢筋设计用钢筋为Q235、HRB335钢筋两种，其技术条件应符合现行国家标准钢筋混凝土用热轧光圆钢筋（GB13013）和钢筋混凝土用热轧带肋钢筋（GB1499）有关规定。根据设计规范3.2.1条，钢筋材料参数取值见下表：表4.2 钢筋材料参数钢筋级别R235HRB335抗拉强度标准值fsk（Mpa）235335抗拉、抗压强度标准值fsd、fsd（Mpa）195280线膨胀系数0.0000120.000012弹性模量Es（Mpa）2.11052.01054.3预应力钢材预应力钢绞线技术条件应符合现行国家标准预应力混凝土用钢绞线（GB/T5224）的规定。材料参数取值见下表：表4.3 预应力钢束材料参数公称直径（mm）15.2公称面积（mm2）139抗拉强度标准值fpk（Mpa）1860抗拉强度设计值fpd（Mpa）1260抗压强度设计值fpd（Mpa）390松弛率2.5弹性模量Es（Mpa）1.95105五、设计参数1、预应力砼结构容重按26.25kN/m3计，沥青混凝土容重按24kN/m3计；2、二期恒载包括桥面铺装为沥青混凝土9cm及两侧防撞墙，二期恒载按90kN/m计；3、混凝土收缩徐变计算模式采用公路钢筋混凝土及预应力混凝土桥涵设计规范（JTG D622004）中有关参数计算，相对湿度为80%，现浇混凝土加载龄期为5天，考虑持续时间为10年；4、桥墩不均匀沉降按20mm考虑，并考虑不同桥墩不均匀沉降最不利组合对结构的影响；5、预应力钢束张拉控制应力为1302Mpa，进行超静定结构计算时，考虑预应力（扣除预应力损失）引起的二次效应；6、预应力管道采用塑料波纹管成形，管道摩擦系数u=0.17，管道偏差系数K=0.0015；7、锚具变形和钢束回缩量为6毫米（单端）；8、设计荷载按公路级荷载标准计算，跨湘江主桥按6个车道考虑，计算时考虑车道荷载的纵、横向折减系数及偏载系数1.2；9、汽车冲击力按规范取值；10、设计基本风速：27.2m/s（离地10m，频率1%，10分钟平均最大风速）。施工阶段按20年一遇计算，使用阶段按100年一遇计算；11、合拢温度按1518计算，体系整体均匀升温20，均匀降温为20；12、竖向温度梯度模式按规范取用；13、计算中未考虑纵向普通钢筋的贡献；14、计算仅考虑50的竖向预应力钢筋的贡献。六、施工顺序说明全桥的施工顺序如下表示：表6.1 步骤工作内容施工天数1浇筑0#块，张拉0#梁段预应力束52浇筑1#块（仅计入湿重不考虑受力）73张拉1#梁段预应力束14安装挂篮、钢筋模板安装155浇筑2#块（仅计入湿重不考虑受力）76张拉2#梁预应力束17移动挂篮，钢筋、模板安装38-48循环步骤5-7，施工3-16#块，同时张拉梁段预应力15449拆除挂篮550安装边跨吊架551浇筑边跨合拢段（仅计入湿重不考虑受力）752张拉边跨合拢段钢束153安装次边跨合拢吊架554浇筑次边跨合拢段（仅计入湿重不考虑受力）755张拉次边跨合拢钢束156安装中跨合拢吊架557浇筑中跨合拢段（仅计入湿重不考虑受力）758张拉中跨合拢段钢束159张拉其它钢束260施工二期3061十年收缩徐变3650七、模型介绍本桥为五跨连续梁，整体模型采用桥梁博士V3.0平面杆系有限元程序计算，按照上述规范及设计标准进行加载，整体模型如下图：图7.1 整体模型结构图上部结构采用梁单元模拟，共有164个单元，165个节点。八、结果分析8.1施工过程主梁应力（1）最大悬臂阶段 图8.1 截面上缘应力（MPa）图8.2截面下缘应力（MPa）此阶段上部结构箱梁上缘处于受压状态，最大压应力为11.1MPa，出现在墩顶附近处；最小压应力为0.0MPa，出现在悬臂端部位置。箱梁下缘除悬臂端部出现拉应力以外，其余部位均处于受压状态。下缘最大压应力为8.7MPa，出现在墩顶附近处；最大拉应力为-0.2MPa，出现在悬臂端部位置。（2）边跨合拢：图8.3 截面上缘应力（MPa）图8.4 截面下缘应力（MPa）此阶段上部结构箱梁上缘处于受压状态，最大压应力为12.0MPa，出现在墩顶附近处；最小压应力为0.0MPa，出现在悬臂处。箱梁下缘除悬臂端部出现拉应力以外，其余部位均处于受压状态。下缘最大压应力为7.8MPa，出现在墩顶附近处；最大拉应力为-0.2MPa，出现在悬臂端部位置。（3）次边跨合拢：图8.5 截面上缘应力（MPa）图8.6 截面下缘应力（MPa）此阶段上部结构箱梁上缘处于受压状态，最大压应力为12.0MPa，出现在墩顶附近处；最小压应力为0.0MPa，出现在悬臂端部。箱梁下缘除悬臂端部出现拉应力以外，其余部位均处于受压状态。下缘最大压应力为8.6MPa，出现在17#及20#墩顶处附近；最大拉应力为-0.2MPa，出现在中跨悬臂端部位置。（4）中跨合拢：图8.7 截面上缘应力（MPa）图8.8 截面下缘应力（MPa）此阶段上部结构箱梁上缘处于受压状态，最大压应力为11.4MPa，出现在墩顶附近处；最小压应力为2.1MPa，出现在中跨合拢段附近。箱梁下缘均处于受压状态。下缘最大压应力为8.3MPa，出现在墩顶附近；最小压应力为2.7MPa，出现在边墩附近。（5）成桥阶段：图8.9截面上缘应力（MPa）图8.10 截面下缘应力（MPa）此阶段上部结构箱梁上缘处于受压状态，最大压应力为11.3MPa，出现在17、20墩墩顶附近；最小压应力为4.9MPa，出现在中跨跨中附近。箱梁下缘均处于受压状态。下缘最大压应力为8.7MPa，出现在中墩墩顶附近；最小压应力为2.9MPa，出现在边墩附近。（7）成桥后10年：图8.11截面上缘应力（MPa）图8.12 截面下缘应力（MPa）此阶段箱梁上缘最大压应力为10.4MPa，出现在17与20#墩顶附近；最小压应力为4.6MPa，出现在中跨跨中附近。箱梁下缘最大压应力为8.9MPa，出现在中墩墩顶附近；最小压应力为2.9MPa，出现在边墩附近。8.2正常使用极限状态压应力验算表8.1 正常使用标准值组合最大正应力（单位：MPa）节点号上缘最大下缘最大节点号上缘最大下缘最大节点号上缘最大下缘最大节点号上缘最大下缘最大14.130.4124312.98.368412.68.4812615.27.0725.763.324312.98.368514.18.6312615.27.0725.763.324412.77.998514.18.6312712.87.5835.833.354412.77.998615.28.1912712.87.5835.833.354514.48.348615.28.1912812.67.1846.616.274514.48.348712.88.8212812.67.1846.616.274615.58.138712.88.82129137.8159.376.624615.58.138812.68.33129137.8159.376.624713.28.918812.68.3413013.38.24611.57.394713.28.918912.78.6413013.38.24611.57.3948138.588912.78.6413113.78.677138.5448138.5890138.9513113.78.677138.544913.29.0290138.9513213.88.81812.59.224913.29.029113.39.2713213.88.81812.59.225013.49.39113.39.2713313.88.89913.210.25013.49.39213.49.2813313.88.89913.210.25113.79.579213.49.28134149.051013.910.45113.79.579313.49.24134149.051013.910.45213.79.549313.49.2413514.39.061114.310.75213.79.549413.59.3113514.39.061113.710.65313.69.479413.59.3113614.59.561214.110.45313.69.479513.99.2513614.59.561214.110.45413.79.59513.99.2513715.19.941314.210.15413.79.596149.6913715.19.941314.210.155149.4296149.6913815.710.21414.59.9855149.429714.61013815.710.21414.59.985614.19.839714.61013916.310.41514.79.95614.19.839815.210.313916.310.41514.19.955714.610.19815.210.314014.610.61614.310.25714.610.19915.810.414015.410.41614.310.25815.210.49915.810.414115.18.771714.910.45815.210.410014.210.614115.18.771714.910.45915.810.51001510.414214.19.21815.510.55915.810.510114.78.8414214.19.21815.510.56014.210.610114.78.8414313.79.741916.210.6601510.510213.89.2614313.79.741916.210.66114.78.8510213.89.2614414.19.212014.610.76114.78.8510313.39.814414.19.212015.410.56213.79.2710313.39.814515.18.82115.18.816213.79.2710413.89.2614515.18.82113.78.896313.39.810413.89.2614615.410.52212.79.36313.39.810514.78.8514614.610.62212.79.36413.79.2610514.78.8514716.210.62312.29.826413.79.261061510.414716.210.62312.29.826514.78.8410614.310.614815.510.52412.79.286514.78.8410715.810.514815.510.52412.79.28661510.410715.810.514914.910.42513.78.866614.210.610815.210.314914.910.42515.18.786715.810.410815.210.315014.310.22615.410.46715.810.410914.610.115014.310.22614.610.66815.110.310914.610.115114.19.942716.210.46815.110.311014.19.815114.79.892716.210.46914.510.111014.19.815214.49.972815.610.26914.510.1111149.3815214.49.972815.610.270149.73111149.3815314.210.12915.19.9470149.7311213.79.4615314.210.12915.19.947113.89.311213.79.461541410.43014.59.567113.89.311313.69.411541410.43014.59.567213.59.3611313.69.4115513.710.63114.39.077213.59.3611413.79.4915514.310.63114.39.077313.49.2911413.79.4915613.910.43213.99.057313.49.2911513.79.515613.910.43213.99.057413.49.3411513.79.515713.310.23313.88.887413.49.3411613.59.2315713.310.23313.88.887513.39.3211613.59.2315812.69.173413.88.817513.39.3211713.28.9315812.69.173413.88.8176139.0211713.28.93159138.573513.78.6576139.0211813.18.47159138.573513.78.657712.78.6811813.18.4716011.57.373613.38.257712.78.6811913.28.8616011.57.373613.38.257812.78.3511913.28.861619.376.63712.97.87812.78.3512015.68.061619.376.63712.97.87912.88.912015.68.061626.616.273812.67.167912.88.912114.48.261626.616.273812.67.168015.28.2312114.48.261635.833.353912.77.648015.28.2312212.77.931635.833.353912.77.648114.18.6412212.77.931645.763.324015.27.18114.18.6412312.98.311645.763.324015.27.18212.68.4912312.98.311654.130.4124114.17.678212.68.4912412.77.794114.17.678312.88.9112412.77.794212.67.858312.88.9112514.27.644212.67.848412.68.4812514.27.64表8.2 正常使用标准值组合主压应力（单位：MPa）（考虑竖向预应力作用）节点号最大主压节点号最大主压节点号最大主压节点号最大主压节点号最大主压节点号最大主压节点号最大主压14.132513.748137213.59513.911913.214214.125.762515.14913.27213.5961411913.214313.725.762615.44913.27313.4961412015.614313.735.832614.65013.47313.49714.612015.614414.135.832716.25013.47413.49714.612114.414414.146.612716.25113.77413.49815.212114.414515.146.612815.65113.77513.39815.212212.714515.159.372815.65213.77513.39915.812212.714615.459.372915.15213.776139915.812312.914614.6611.52915.15313.6761310014.212312.914716.2611.53014.55313.67712.71001512412.714716.27133014.55413.77712.710114.712412.714815.57133114.35413.77812.710114.712514.214815.5812.53114.355147812.710213.812514.214914.9812.53213.955147912.810213.812615.214914.9913.23213.95614.17912.810313.312615.215014.3913.23313.85614.18015.210313.312712.815014.31013.93313.85714.68015.210413.812712.815114.11013.93413.85714.68114.110413.812812.615114.71114.33413.85815.28114.110514.712812.615214.41113.73513.75815.28212.610514.71291315214.41214.13513.75915.88212.6106151291315314.21214.13613.35915.88312.810614.313013.315314.21314.23613.36014.28312.810715.813013.3154141314.23712.960158412.610715.813113.7154141414.53712.96114.78412.610815.213113.715513.71414.53812.66114.78514.110815.213213.815514.31514.73812.66213.78514.110914.613213.815613.91514.13912.76213.78615.210914.613313.815613.91614.33912.76313.38615.211014.113313.815713.31614.34015.26313.38712.811014.11341415713.31714.94015.26413.88712.8111141341415812.61714.94114.16413.88812.61111413514.315812.61815.54114.16514.78812.611213.713514.3159131815.54212.66514.78912.711213.713614.5159131916.24212.666158912.711313.613614.516011.51916.24312.96614.2901311313.613715.116011.52014.64312.96715.8901311413.713715.11619.372015.44412.76715.89113.311413.713815.71619.372115.14412.76815.19113.311513.713815.71626.612113.74514.46815.19213.411513.713916.31626.612212.74514.46914.59213.411613.513916.31635.832212.74615.56914.59313.411613.514014.61635.832312.24615.570149313.411713.214015.41645.762312.24713.270149413.511713.214115.11645.762412.74713.27113.89413.511813.114115.11654.132412.748137113.89513.911813.114214.1图8.13 正常使用标准组合上缘最大压应力图8.14 正常使用标准组合下缘最大压应力图8.15 正常使用标准组合主压应力（考虑竖向预应力）从以上图表可见，截面上缘最大压应力为16.3MPa，下缘最大压应力10.7MPa，规范限值为,满足要求。截面最大主压应力为16.3MPa（考虑50竖向预应力作用的数值）, 规范限值,满足要求。8.3正常使用极限状态抗裂验算表8.3 短期效应组合最小正应力（单位：MPa）节点号上缘下缘节点号上缘下缘节点号上缘下缘节点号上缘下缘100434.534.38844.141267.574.121.622.87434.534.38855.784.241267.564.121.622.87444.284.05855.784.241275.535.0131.592.83444.284.06867.114.041275.535.0131.592.83455.914.21867.114.041285.73542.165.33455.914.21875.014.951285.73542.165.33467.183.97875.014.951296.165.5854.034.86467.183.97885.24.981296.155.5854.034.86475.014.84885.24.981306.635.9865.414.97475.014.85895.695.671306.625.9865.414.97485.154.85895.685.671317.046.3776.395.56485.154.85906.186.121317.046.3776.395.56495.65.51906.186.121327.216.5185.535.98495.65.51916.636.551327.216.5185.535.98506.115.98916.636.551337.256.5996.036.78506.115.98926.836.71337.256.5996.036.78516.566.43926.836.71347.516.77106.696.92516.566.43936.926.81347.516.77106.696.92526.786.61936.926.81357.876.79117.097.17526.786.61947.216.981357.876.79116.517.15536.876.72947.216.981368.17.3126.887.03536.876.72957.67.011368.17.3126.887.03547.176.92957.67.011378.677.71137.126.92547.176.92967.857.531378.677.71137.126.92557.576.96967.857.531389.38.02147.536.97557.576.96978.457.951389.38.02147.536.97567.827.5978.457.951399.928.24157.867.05567.827.5989.18.251399.928.24157.297.11578.437.93989.18.251408.418.52167.657.54578.437.93999.748.471409.28.37167.657.54589.088.23999.748.471418.957.03178.347.9589.088.231008.268.731418.957.03178.347.9599.728.451009.058.581427.957.43189.078.15599.728.451018.817.21427.957.43189.078.15608.268.731018.817.21437.467.92199.778.33609.048.571027.817.611437.467.92199.778.33618.817.21027.817.611447.937.44208.348.58618.817.21037.338.11447.937.44209.138.42627.817.611037.338.11458.927.04218.927.05627.817.611047.817.611458.927.04218.927.05637.338.11047.817.611469.168.41227.937.44637.338.11058.87.21468.378.56227.937.44647.817.611058.87.21479.778.33237.457.92647.817.611069.078.571479.778.33237.457.92658.817.211068.288.721489.068.15247.947.43658.817.211079.718.461489.068.15247.947.43669.078.581079.718.461498.357.9258.947.03668.288.731089.068.241498.357.9258.947.03679.738.471089.068.241507.667.53269.228.37679.738.471098.427.931507.667.53268.438.53689.088.261098.427.931517.287.1279.918.25689.088.261107.837.491517.867.04279.918.25698.457.951107.837.491527.516.97289.278.03698.457.951117.566.961527.516.97289.278.03707.867.531117.566.961537.166.91298.667.73707.867.531127.156.921537.166.91298.667.72717.597.011127.156.921546.877.02308.097.31717.597.011136.916.721546.877.02308.097.31727.196.981136.916.721556.517.15317.856.8727.196.981146.756.611557.17.16317.856.8736.956.81146.756.611566.76.9327.476.78736.956.81156.566.421566.76.9327.476.78746.816.711156.566.421576.126.75337.276.6746.816.711166.125.991576.126.75337.276.6756.636.541166.125.991585.59