某某特大桥主桥上部结构设计(60+2110+60)连续梁桥方案计算书终版毕业论文

'摘要本设计为宁乡大桥主桥上部结构设计。该桥全长340m，设计的跨径为60m+2*110m+60m，截面为单箱单室的变截面形式。整个设计可以分成两个部分：第一部分，结构建摸和内力计算。在选择桥的桥型及孔径划分、主梁截面形式与主梁高度的拟定、截面细部尺寸拟定，随后进行结构内力计算。在完成了恒载内力的计算后，又进行了活载内力计算、次内力计算、内力组合计算，并画出内力包络图。第二部分，预应力钢束估算及布置，预应力损失及有效预应力计算，钢束布置后的内力计算及组合，强度计算与验算，应力、应变及其它验算。关键词：预应力连续箱梁；建立模型；内力计算；强度验算 TheSuperstructureDesignofmacheBridgeAbstractThedesignistheoneofthesuperstructureofjiujiangbridge.Thewholespanofthebridgeis340m.Thisbridgedesignsthespanis60m+2*110m+60m,Thecrosssectionalongthespanisthedifferentbesidesthecrosssectionisoneboxwithoneroom.Theentiredesignmaydivideintotwoparts：Thefirstpartofthepaperisaboutthemodelingofthebridgeandthecomputationofinternalforces.TheFEMmodelofthebridgeisestablishedafterthestyleofthebridge,thelengthofeveryspanthecrosssectionandtheheightofthemainbeamaredecided.Theneverykindofinternalforcesiscomputed.Theseforcesincludetheforcesofdeadload,liveloadandsomesecondaryforces.Finallytheseloadsarecombinedandthegraphoftheutmostforcesisdrawn.Thesecondoneisaboutthearrangementofprestressedsteelbarsandotherkindsoftests.Thenumberofthebarsareestimatedandarrangedbeforethelossoftheprestressandtheeffectiveonearecaculated.Thenthetestsofthestrength,thestressandthedeformationofthebridgearecarriedoutinthepaper.Keywords:pre-stressedconcretecontinuousbridge；establishmentmodel;Endogenicforcecomputationintensitycheckingcalculation. 目录目录1前言3第一章工程概述41.1工程概况41.2设计条件41.2.1工程地质和地震41.2.2气象和水文41.3设计标准和设计规范及建筑材料41.3.1设计规范41.3.2主要技术标准41.3.3主要建筑材料51.4桥型总体布置61.4.1桥跨布置61.5桥梁构造6第二章主桥结构计算分析72.1计算模型和施工阶段划分72.2悬臂节段划分及单元划分72.3主要计算荷载如下8第三章恒载内力计算及变形分析93.1毛截面特性计算93.2恒载集度计算113.2.1一期恒载集度113.2.2二期恒载集度123.3时程内力计算123.3.1梁段悬臂施工内力123.3.2边跨梁体合拢内力143.3.3中跨梁体合拢内力173.4恒载内力结果203.4.1一期恒载内力203.4.2二期恒载内力223.4.3总恒载内力27第四章活载内力计算及内力组合30 4.1汽车和人群活载内力计算304.2温度次内力计算344.3支座沉降次内力计算374.4荷载组合及内力包络图384.4.1组合方法384.4.2计算结果404.4.3内力包络图56第五章预应力钢束估算与布置585.1钢束估算585.1.1估算原理585.1.2钢束估算结果595.2横向预应力布置615.3竖向预应力布置605.4预应力损失及有效预应力计算605.4.1预应力损失及有效预应力计算方法605.5主梁次内力计算645.5.1预应力产生的二次内力64第六章主要控制截面应力及承载能力验算666.1强度验算原理666.1.1承载能力极限状态验算666.1.2使用阶段正截面应力验算71第七章变形计算与预拱度设置及锚下局部应力验算737.1挠度计算737.1.1变形计算、验算及预拱度设置737.1.2变形计算结果747.2变形验算及预拱度设置75外文文献77参考文献87 前言毕业设计是高等工科院校本科培养计划中最后一个重要的教学环节，目的是使学生在学完培养计划所规定的基础课、技术基础课及各类必修和选修专业课程之后，通过毕业设计这一环节，较为集中和专一地培养学生综合运用所学的基础理论、基本知识和基本技能，分析和解决实际问题的能力。和以往的理论教学不同，毕业设计是要学生在教师的指导下，独立地、系统地完成一个工程设计，以期能掌握一个工程设计的全过程，在巩固已学课程的基础上，学会考虑问题、分析问题和解决问题，并可以继续学习到一些新的专业知识，有所创新。毕业设计是培养学生独立工作的一种良好途径和方法，它的实践性和综合性是其它教学环节所不能替代的。悬臂浇筑预应力混凝土连续梁桥作为无支架施工有利于通航河流建桥、深山峡谷建桥和城市立交建桥等。悬臂施工的受力特点接近于成桥后的结构受力。悬臂施工法在我国已有成熟的经验，悬臂浇筑预应力混凝土梁桥得到飞跃发展，并成为当代桥梁建筑中最基本的桥型之一。通过对麻车大桥主桥的初步设计，使我进一步加深了对桥梁设计与施工理论知识的理解，对悬臂施工连续箱梁有了初步了解，是对大学四年所学知识的总结。本设计中用到了结构力学、材料力学、结构设计原理、桥梁工程等学科的诸多知识。并且我从图书馆借阅了大量参考书籍力求将设计做到规范、合理、清楚。虽然该桥结构不算复杂，但整个结构设计计算量大，数据众多，难度较大。当然，也正是由此，我得到切实的锻炼和提高，它使我这四年所学的专业知识更加系统化、具体化，对我以后从事桥梁方面的工作具有很好的指导意义。通过设计让我了解连续梁桥的主要特点和施工方法，了解和掌握桥梁设计的全过程；通过老师的指导，培养学生独自完成桥梁工程的设计计算；锻炼学生综合运用专业基础知识、专业知识的能力，培养学生的创新能力。在设计过程中，我得到了李其林老师，路桥其他老师的悉心指导，及其杨龙同学的耐心帮助，在此一并表示衷心的感谢！由与本人的水平有限，在设计中一定存在着缺点和错误，恳请老师和同学们批评指正。 第一章工程概述1.1工程概况本项目位于长沙市宁乡县，是宁乡县交通圈的重要组成部分。该特大桥的建设将为宁乡县经济圈的发展壮大提供便捷的交通支撑，同时也保证居民过江安全1.2设计条件1.2.1工程地质和地震地质：桥位区内地质构造较为简单，岩层为单斜构造，无断裂构造。桥位周边地势较为平坦，发生灾害地质的可能性较小。区内不良地质现象主要为淤泥质土和表层软土，埋藏深度一般为0.3~1.2m；砂卵石层中局部含泥量较高，且多位于稍密状态，胶结性较差。地震：据区域资料，本区在燕山期及以前的地质年代里，构造运动强烈，到喜山期基本结束了大规模的断裂和褶裂，地壳运动主要表现为升降运动，深、大断裂逐渐趋于稳定，从上更新世以来，本区地壳垂直上升速率小于0.17mm/年，地壳基本处于稳定状态。本区近代地震的特点是强度弱，震级小，频度低。1.2.2气象和水文项目所在区域地处亚热带季风气候区，气候温暖，湿润多雨，从季节变化看，冬季在冷高压控制下，气候干冷，但河道不封冻；夏季在副热带控制下，天气睛热。气温：1月份平均气温6℃，7月份平均32℃，年平均无霜期在265天左右，年均总降雨量1600毫米。6-7月的梅雨季节，该季节降雨强度大，持续时间长，往往造成江河洪涝灾害。常风向东北风（14%），多年平均风速1.6M/s.多年平均暴日数36天，多年平均雾日18.9天。1.3设计标准和设计规范及建筑材料1.3.1设计规范1）JTGD60-2004《公路桥涵设计通用规范》（2）JTGD62-2004《公路钢筋混凝土及预应力混凝土桥涵设计规范》（3）JTGD63-2007《公路桥涵地基与基础设计规范》（4）姚玲森.桥梁工程.人民交通出版社,2008（5）邹毅松，王银辉.桥梁计算示例丛书-连续梁桥.人民交通出版社,2009（6）陈忠延.土木工程专业毕业设计指南-桥梁工程分册.中国水利水电出版社,2000（7）范立础.预应力混凝土连续梁桥.人民交通出版社,1999 1.3.2主要技术标准（1）设计荷载：汽车荷载等级-公路I级；汽车荷载-3.05KN/m。人群荷载标准按《JTGD60-2004》4.3.5取值，本桥主跨110m，人群荷载应取2.9KN/m，由于桥位处在城镇郊区人群密集地区，故标准提高15%。（2）桥梁宽度：桥梁总宽12m。其中：行车道4×3.75m非机动车道2×1.925m防撞护栏2×0.5m（3）桥面横坡：2%。（4）设计洪水频率：1/100。（5）设计最高通航水位27.6m，通航净空：净宽102m，净高7m。本桥主桥110m主跨为双向通航孔，60m边跨禁止通航。（6）船舶撞击作用：按四级内河航道船舶吨级为500t，顺桥向撞击作用为450KN,横桥向撞击作用为550KN。（7）桥梁护栏：主桥防撞护栏采用SB级1.3.3主要建筑材料混凝土：对于简支转连续施工，预制梁及其现浇接缝、封锚、墩顶现浇连续段、桥面现浇层均采用C50混凝土，基桩采用C25，其余构件采用C30；对于悬臂施工，主梁采用C50混凝土，墩身、承台采用C30混凝土，基桩采用C25。预应力钢绞线：采用《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62-2004）中d＝15.2mm的钢绞线，公称面积为140mm2，标准强度fpk＝1860MPa，弹性模量Ep＝1.95×105MPa。普通钢筋：R235、HRB335钢筋标准应符合GB13013-1991和GB1499-1998的规定。凡钢筋直径≥12mm者，均采用HRB335热轧带肋钢筋；凡钢筋直径<12mm者，采用R235钢筋，钢板应符合GB700-88规定的Q235钢板。锚具：对于简支转连续施工，预制梁采用OVM15型锚具及其配套设备；接头顶板束采用BM15型锚具及其配套设备；对于悬臂施工，预应力锚具采用符合国际后张法预应力混凝土协会FIP标准的I类锚具，其锚固效率系数大于95％。预应力管道：采用预埋圆形和扁形塑料波纹管成型。支座：对于简支转连续施工，桥梁支座根据设置部位不同，分别采用GYZ、GYZF4板式橡胶支座，其技术性能应符合《公路桥梁板式橡胶支座》（JT/T4-93）的要求；对于悬臂施工，主桥支座采用GPZ（II）系列支座。1.4桥型总体布置1.4.1桥跨布置麻车大桥总长340m，全桥孔径布置为：60+2*110+60m，采用预应力砼变截面连续箱梁。桥型布置图见图1.1。 图1.11.5桥梁构造上部：主桥箱梁采用变截面连续箱梁，根部（中支点）梁高6.775m，跨中高度2.8m，梁底曲线采用二次抛物线。箱梁采用单箱单室直腹板断面，顶宽19.85m，底宽12.85m，悬臂长3.5m，顶板厚度18cm，底板厚30-78.04cm，腹板厚60-100cm。箱梁设三向预应力，纵向采用高强度低松弛钢绞线，大吨位群锚体系；竖向采用精轧螺纹钢筋，该预应力筋在施工中可兼作挂篮的后锚点；横向采用高强度低松弛钢绞线，扁锚体系。其他：桥面铺装：主桥采用10cm沥青砼铺装防水层；引桥采用8cm水泥混凝土+防水层+10cm沥青砼铺装。伸缩缝：全桥伸缩缝分别采用80mm、160mm两种规格的浅埋式三防伸缩缝。支座：主桥主墩和边墩采用GPZ(II)系列盆式橡胶支座；引桥桥墩采用板式橡胶支座。箱梁断面见图1.2。跨中处截面支点处截面图1.2（单位cm） 第二章主桥结构计算分析2.1计算模型和施工阶段划分遵循结构离散化的原则，全桥以下原则在适当位置划分节点：1）截面的变化点；2）施工分界点、边界处及支座处；3）需验算或求位移的截面处。本设计的单元划分，每一个施工阶段除0号块外自然划分为一个单元。这样便于模拟施工过程，而且这些截面正是需要验算的截面。另外，在墩顶、跨中和一些构造变化位置相应增设了几个单元。这样主桥箱梁共离散为104个单元，105个节点。主桥部分的内力分析按照四跨连续梁的施工顺序考虑施工各阶段不同受力体系计算。本桥的施工采用悬臂浇筑，共分56个施工阶段，以浇筑节段砼，张拉相应钢束，移动挂篮为一个标准循环。根据不同施工阶段结构受力体系、荷载、预应力、解除多余约束、支座不均匀。温度变化等进行了内力及位移的计算，同时考虑预应力前期损失如混凝土收缩、徐变、钢筋松弛、弹性压缩引起预应力变化。在主桥箱梁浇筑完毕，结构体系转变为三跨连续梁状态，张拉完预应力钢束后，然后施工桥面铺装，安装防撞护栏等二期恒载。结构在使用状态下进行荷载内力计算。2.2悬臂节段划分及单元划分0号块长度的取值应考虑为1号块的浇注提供足够的作业平台，同时也不应该太大，以免浪费材料，增加主梁自重。本设计0号块长度为8米，以满足这些要求,0号段自重6527.6kN。其他各节段长度及重量（只取一个悬臂长度）如下表：表2.1各悬臂节段长度节段1、1＇2、2＇3、3＇4、4＇5、5＇6、6＇7、7＇8、8＇9、9＇长度(m)3.03.03.03.03.03.53.54.04.0节段10、10＇11、11＇12、12＇13、13＇14、14＇15/216＇17＇长度(m)4.04.04.04.04.02.02.02.0图2.1主桥单元划分示意图（尺寸单位：m） 2.3主要计算荷载如下(1)、恒载：箱梁自重，防撞护栏，桥面铺装。(2)、活载：汽车荷载等级-公路I级；人群荷载-3.05KN/m2。(3)、施工荷载：主在要为挂篮荷载，挂篮荷载受力作用点的结构形式，设计挂篮自重（包括模板及临时机具）以悬浇节段的最大重量的0.5作控制(4)、支点不均匀沉降：按每个桥墩可能出现最大相对沉降0.5cm来考虑。(5)、温度影响:均匀温度。 第三章恒载内力计算及变形分析3.1毛截面特性计算在计算静载所引起的效应时要用到静载所引起的内力增量以及各控制截面的毛截面特性,毛截面特性列如下表：表3.1毛截面特性单元号节点号节点X坐标节点Y坐标截面高度(m)截面面积(m2)截面抗弯惯距(m4)截面中性轴高度(m)11078.86122.814.112513.43491.66122278.86122.814.11259.20011.661222278.86122.814.11259.20011.66123478.73742.814.11259.44381.661233478.73742.814.112516.56541.66124678.73742.814.112516.67781.661244678.73742.814.11259.64801.661251078.81612.882814.333016.63881.6989551078.81612.882814.333016.63881.698961478.74123.018314.694818.95281.7595661478.74123.018314.694818.95281.759571878.63893.215.179722.34671.8389771878.63893.215.179722.34671.838982278.49313.423415.550926.69961.9165882278.49313.423415.550926.69961.916592678.33893.683416.243932.70642.0223992678.33893.683416.243932.70642.0223103078.16053.977917.029540.41692.138410103078.16053.977917.029540.41692.1384113477.95954.304718.976151.59772.2642 11113477.95954.304718.976162.39522.38311237.577.76724.615919.886762.39522.3831121237.577.76724.615919.886779.07562.5202134177.57044.949822.938979.07562.520213134177.57044.949822.938992.95912.6370144477.38375.253323.960492.95912.637014144477.38375.253323.9604109.07402.7582154777.18585.572425.0337109.07402.758215154777.18585.572425.0337127.69962.8834165076.97675.906726.1591127.69962.883416165076.97675.906726.1591149.12313.0128175376.75706.255827.3336149.12313.012817175376.75706.255827.3336124.20453.1460185676.52676.619328.5564124.20453.146018185676.52676.619328.5564232.88643.24981958.2576.47486.77555.3588232.88643.2498191958.2576.47486.77555.3588332.64083.4166206076.64166.77579.7088332.64083.4166 3.2恒载集度计算3.2.1一期恒载集度一期荷载集度包括箱梁、横隔板、齿板集度。表3.2箱梁自重表单元号截面高度截面面积单元重单元号截面高度截面面积单元重12.814.112573.32114.304718.976117682.814.11254.615919.886722.814.112573.32124.615919.886719242.814.11254.949822.938932.814.11252035.8134.949822.93891827.82.814.11255.253323.960442.814.11251479.4145.253323.960419112.882814.33305.572425.033752.882814.33301510.6155.572425.03371996.83.018314.69485.906726.159163.018314.69481552.2165.906726.15912085.23.215.17976.255827.333673.215.17971599176.255827.33362178.83.423415.55096.619328.556483.423415.55091653.6186.619328.55642454.43.683416.24396.77555.358893.683416.24391729196.77555.35883073.23.977917.02956.77579.7088103.977917.029518724.304718.9761 3.2.2二期恒载集度桥面铺装和防撞护栏每米重量计算q=0.1×19.85×26+2×0.342×26=69.349kN/m3.3时程内力计算桥梁结构特别是大跨度桥梁结构的分段施工，一般总要经历一个长期而又复杂的施工过程以及结构体系转换过程。随着施工阶段的推进，桥梁结构形式、支承约束条件、荷载作用方式等都在不断变化。分段施工中的结构受力状态是逐工况逐阶段累计形成的，为了真实反映实际结构的受力性能，每个工况或每个阶段的结构受力分析必须独立进行，而中间施工阶段或最终成桥状态的结构受力是已经完成的各个工况或各个阶段的结构受力状态的叠加结果，因此有必要了解施工阶段结构的受力性能。3.3.1梁段悬臂施工内力从墩顶0号块件开始的梁段双悬臂施工时的结构受力状态与静定T形刚架的受力相似，因此，在整个梁段悬臂施工中，最不利受力状态出现在最长双悬臂时，即梁段悬臂施工的最后阶段，阶段累计结果如下表(因本桥两个悬臂T施工完全一样所以只列出一个悬臂施工的接段内力)表3.3最大悬臂施工阶段内力单元号节点号弯矩（KN.m）剪力（KN）轴力（KN）1100022-733.85733.8504400055-2950.69-1479.17066-14273.3-2988.62077-31717.1-4542.09088-55467-6140.08099-85708.2-7793.4101010-122713-9523.6301111-166881-11395.901212-212238-13164.201313-264042-15112.70 1414-314105-17741.801515-370175-19652.601616-432106-21649.101717-500160-23735.301818-574611-2591501919-6355633076.59402020-6327063.80802121-63554928469.5502222-57459825915.0302323-50014723735.3202424-43209321649.1102525-37016219652.5902626-31409217741.8202727-26403315912.7502828-21223413964.1802929-16688111395.9203030-1227139523.62903131-85708.27793.41203232-554676140.08103333-31717.14542.08903434-14273.32988.61603535-2950.691479.167037370003838-2950.69-1479.1703939-14273.3-2988.6204040-31717.1-4542.0904141-55467-6140.0804242-85708.2-7793.410 4343-122713-9523.6304444-166881-11395.904545-212238-13164.204646-264042-15112.704747-314105-17741.804848-370175-19652.604949-432106-21649.105050-500160-23735.305151-574611-2591505252-6355633076.5940图3.1最大悬臂阶段弯矩图图3.2最大悬臂阶段剪力图3.3.2边跨梁体合拢内力边跨梁体合拢段是在支架上施工的，施工完成后一次性拆除施工支架，因此，合拢段荷载以一次落架方式作用在一端固定，另一端简支的超静定固端梁上，解一次超静定结构即可求得结构弯矩图。将边跨梁体合拢引起的结构弯矩与梁段悬臂施工引起的结构弯矩叠加，即可求得边跨梁体合拢后的结构累计弯矩，其值列如下表(列出一半单元)：表3.4边跨合拢阶段内力单元号节点号弯矩(KN.m)剪力(kN)轴力(KN)110-2391.24022-5516.322720.24254.596 33-800.4891986.39254.596441128.339-48.36854.59655-4413.21-1527.5454.59666-15925.2-3036.9854.59677-33556.9-4590.4654.59688-57492.3-6188.4554.59699-87918.5-7841.7854.5961010-125107-957254.5961111-169458-11444.354.5961212-214973-13212.554.5961313-266936-15161.154.5961414-317134-17790.254.5961515-373339-1970154.5961616-435403-21697.554.5961717-503590-23783.754.5961818-578174-25963.454.5961919-6392314124.71954.5962020-6345491051.93354.5962121-63554928469.5502222-57459825915.0302323-50014723735.3202424-43209321649.1102525-37016219652.5902626-31409217741.8202727-26403315912.7502828-21223413964.1802929-16688111395.9203030-1227139523.6290 3131-85708.27793.41203232-554676140.08103333-31717.14542.08903434-14273.32988.61603535-2950.691479.167037370003838-2950.69-1479.1703939-14273.3-2988.6204040-31717.1-4542.0904141-55467-6140.0804242-85708.2-7793.4104343-122713-9523.6304444-166881-11395.904545-212238-13164.204646-264042-15112.704747-314105-17741.804848-370175-19652.604949-432106-21649.105050-500160-23735.305151-574611-2591505252-6355633076.5940图3.3边跨合拢阶段弯矩图 图3.4边跨合拢阶段剪力图图3.5边跨合拢阶段轴力图3.3.3中跨梁体合拢内力中跨梁体合拢阶段的结构内力计算，应该分成两个阶段进行。在中跨合拢段与单悬臂梁连接成整体前，其重力由吊杆平均传至两个悬臂端；当合拢段两端形成固端，整个结构变成连续梁后，吊杆传递的重力应当卸去，而代之以合拢段本身的均布重力。将形成整体前后的结构弯矩相叠加可得中跨梁体合拢阶段的结构弯矩，再将中跨梁体合拢引起的结构弯矩与上一施工阶段结束时的结构累积弯矩相叠加，即可得到按悬臂施工法最终形成的连续梁结构总弯矩。各截面内力值列表如下(列出一半单元)：表3.5中跨合拢阶段内力单元号节点号弯矩(KN.m)剪力(kN)轴力(KN)1104992.3360229134.5732078.3286817.923313589.581228.2276817.924412746.57-922.7836817.92553547.15-2634.456817.9266-12351-4376.46817.9277-35113.5-6162.376817.9288-64815.4-7992.866817.9299-101882-9878.76817.921010-146475-11841.46817.92 1111-199010-13946.26817.921212-252338-15917.96817.921313-312794-18069.96817.921414-370717-20873.46817.921515-435094-22958.56817.921616-505779-25129.46817.921717-583037-273906817.921818-667144-29744.16817.921919-736504-32429.46817.922020-79700935994.986817.922121-73582032820.486817.922222-66558030135.186817.922323-58029927781.096817.922424-50186825520.56817.922525-43001023349.616817.922626-36445921264.466817.922727-30536819261.016817.922828-24354717109.016817.922929-18885414337.326817.923030-13475512232.526817.923131-88597.210269.816817.923232-49966.58383.9746817.923333-18700.26553.4836817.9234345626.7544767.5096817.92353523089.353025.566817.92363632201.65513.8936817.92373729929.97-1637.126817.92383817473.03-4148.786817.92 3939-4482.46-5890.736817.924040-33302.3-7676.716817.924141-69061.5-9507.26817.924242-112185-113936817.924343-162836-13355.76817.924444-221428-15460.56817.924545-280056-17432.26817.924646-345812-19584.26817.924747-408278-22387.76817.924848-477199-24472.86817.924949-552426-26643.76817.925050-634227-28904.36817.925151-722877-31258.46817.925252-795645-33943.76817.92图3.6中跨合拢阶段弯矩图图3.7中跨合拢阶段剪力图图3.8中跨合拢阶段轴力图 3.4恒载内力结果将以上荷载信息汇总写入GQJS计算程序，电算处理后得各截面恒载内力值，经手算核对GQJS计算程序计算得数据符合要求，取出全桥控制截面恒载内力列如下：3.4.1一期恒载内力表3.6一期恒载内力表单元号节点号弯矩(KN.m)剪力(kN)轴力(KN)1104992.3360229134.5732078.3286817.923313589.581228.2276817.924412746.57-922.7836817.92553547.15-2634.456817.9266-12351-4376.46817.9277-35113.5-6162.376817.9288-64815.4-7992.866817.9299-101882-9878.76817.921010-146475-11841.46817.921111-199010-13946.26817.921212-252338-15917.96817.921313-312794-18069.96817.921414-370717-20873.46817.921515-435094-22958.56817.921616-505779-25129.46817.921717-583037-273906817.921818-667144-29744.16817.921919-736504-32429.46817.922020-79700935994.986817.92 2121-73582032820.486817.922222-66558030135.186817.922323-58029927781.096817.922424-50186825520.56817.922525-43001023349.616817.922626-36445921264.466817.922727-30536819261.016817.922828-24354717109.016817.922929-18885414337.326817.923030-13475512232.526817.923131-88597.210269.816817.923232-49966.58383.9746817.923333-18700.26553.4836817.9234345626.7544767.5096817.92353523089.353025.566817.92363632201.65513.8936817.92373729929.97-1637.126817.92383817473.03-4148.786817.923939-4482.46-5890.736817.924040-33302.3-7676.716817.924141-69061.5-9507.26817.924242-112185-113936817.924343-162836-13355.76817.924444-221428-15460.56817.924545-280056-17432.26817.924646-345812-19584.26817.924747-408278-22387.76817.924848-477199-24472.86817.92 4949-552426-26643.76817.925050-634227-28904.36817.925151-722877-31258.46817.925252-795645-33943.76817.92图3.9一期恒载弯矩图图3.10一期恒载弯矩图图3.11一期恒载轴力图3.4.2二期恒载内力即桥面铺装的恒载内力。表3.7二期恒载内力表单元号节点号轴力(KN)剪力(KN)弯矩(KN.m)110-154.6550120-270.905-425.56223516.214589.221-425.56233516.214472.971636.632333516.214472.9711228.927343516.214356.7212058.619 443516.214356.7211466.324453516.214124.2212586.664553516.214124.2212586.664563516.214-108.2792881.868663516.214-108.2792881.868673516.214-340.7792343.432773516.214-340.7792343.432783516.214-573.2791028.022883516.214-573.2791028.022893516.214-805.779-1187.99993516.214-805.779-1187.999103516.214-1038.28-4248.5810103516.214-1038.28-4248.5810113516.214-1270.78-8160.0811113516.214-1270.78-8160.0811123516.214-1474.22-12287.712123516.214-1474.22-12287.712133516.214-1677.65-17111.413133516.214-1677.65-17111.413143516.214-1852.03-21749.414143516.214-1852.03-21749.414153516.214-2026.4-26871.115153516.214-2026.4-26871.115163516.214-2200.78-32476.916163516.214-2200.78-32476.916173516.214-2375.15-38568.117173516.214-2375.15-38568.117183516.214-2549.53-45145.4 18183516.214-2549.53-45145.418193516.214-2680.31-50846.619193516.214-2680.31-50846.619203516.214-2782.03-56212.720203516.2142997.878-56212.720213516.2142896.159-50468.921213516.2142896.159-50468.921223516.2142765.378-4428222223516.2142765.378-4428222233516.2142591.003-37057.123233516.2142591.003-37057.123243516.2142416.628-30318.424243516.2142416.628-30318.424253516.2142242.253-24065.125253516.2142242.253-24065.125263516.2142067.878-18295.826263516.2142067.878-18295.826273516.2141893.503-13010.327273516.2141893.503-13010.327283516.2141690.066-7431.128283516.2141690.066-7431.128293516.2141486.628-2548.0129293516.2141486.628-2548.0129303516.2141254.1282226.88730303516.2141254.1282226.88730313516.2141021.6286150.87331313516.2141021.6286150.87331323516.214789.1289230.279 32323516.214789.1289230.27932333516.214556.62811409.0933333516.214556.62811409.0933343516.214324.12812810.9234343516.214324.12812810.9234353516.21491.62813379.1135353516.21491.62813379.1135363516.214-140.87213122.1636363516.214-140.87213714.4636373516.214-257.12213316.4637373516.214-257.12212724.1737383516.214-489.62211389.1438383516.214-489.62211389.1438393516.214-722.1229228.9739393516.214-722.1229228.9739403516.214-954.6226235.16140403516.214-954.6226235.16140413516.214-1187.122464.37941413516.214-1187.122464.37941423516.214-1419.62-220742423516.214-1419.62-220742433516.214-1652.12-7722.9743433516.214-1652.12-7722.9743443516.214-1884.62-14089.844443516.214-1884.62-14089.844453516.214-2088.06-20365.945453516.214-2088.06-20365.945463516.214-2291.5-27338.1 46463516.214-2291.5-27338.146473516.214-2465.87-33817.647473516.214-2465.87-33817.647483516.214-2640.25-40780.848483516.214-2640.25-40780.848493516.214-2814.62-48228.149493516.214-2814.62-48228.149503516.214-2989-56160.850503516.214-2989-56160.850513516.214-3163.37-64579.751513516.214-3163.37-64579.751523516.214-3294.15-7166252523516.214-3294.15-7166252533516.214-3395.87-78102.3图3.12二期恒载弯矩图图3.13二期恒载弯矩图图3.14二期恒载轴力图 3.4.3总恒载内力表3.9控制截面总恒载内力单元号节点号弯矩(KN.m)剪力(kN)轴力(KN)1104992.3360229134.5732078.3286817.923313589.581228.2276817.924412746.57-922.7836817.92553547.15-2634.456817.9266-12351-4376.46817.9277-35113.5-6162.376817.9288-64815.4-7992.866817.9299-101882-9878.76817.921010-146475-11841.46817.921111-199010-13946.26817.921212-252338-15917.96817.921313-312794-18069.96817.921414-370717-20873.46817.921515-435094-22958.56817.921616-505779-25129.46817.921717-583037-273906817.921818-667144-29744.16817.921919-736504-32429.46817.922020-79700935994.986817.922121-73582032820.486817.922222-66558030135.186817.922323-58029927781.096817.922424-50186825520.56817.922525-43001023349.616817.922626-36445921264.466817.92 2727-30536819261.016817.922828-24354717109.016817.922929-18885414337.326817.923030-13475512232.526817.923131-88597.210269.816817.923232-49966.58383.9746817.923333-18700.26553.4836817.9234345626.7544767.5096817.92353523089.353025.566817.92363632201.65513.8936817.92373729929.97-1637.126817.92383817473.03-4148.786817.923939-4482.46-5890.736817.924040-33302.3-7676.716817.924141-69061.5-9507.26817.924242-112185-113936817.924343-162836-13355.76817.924444-221428-15460.56817.924545-280056-17432.26817.924646-345812-19584.26817.924747-408278-22387.76817.924848-477199-24472.86817.924949-552426-26643.76817.925050-634227-28904.36817.925151-722877-31258.46817.925252-795645-33943.76817.92 图3.15恒载弯矩图图3.16恒载剪力图图3.17恒载剪力图 第四章活载内力计算及内力组合活载内力为基本可变荷载（包括汽车、人群等）在桥梁使用阶段所产生的结构内力。很明显，不管采用什么施工方法，这是结构已成为最终体系——连续梁桥，因此力学计算图式已十分明确。4.1汽车和人群活载内力计算当一个单位集中荷载P=1沿结构移动时，表示结构上某量（如支座反力，某一指定截面的弯矩、剪力或轴力等）变化规律的曲线，称为Z的影响线。作影响线时，单位荷载沿主梁移动，主梁一般分为许多单元，而这些单元一般较短，因此，可以考虑单位荷载只在主梁上的结点上按从左到右的顺序移动，这样每次单位荷载加载均为结点荷载，将每次加载后得到的指定截面内力和将其用线形表示出来，即影响线图例，求得内力影响线值，根据其值可做内力影响线图。图4.1墩支座截面弯矩、剪力、轴力影响线图4.2边跨L/4截面弯矩、剪力、轴力影响线图4.3边跨L/2截面弯矩、剪力、轴力影响线图4.4中跨跨中截面弯矩、剪力、轴力影响线 图4.5墩支座截面弯矩、剪力、轴力影响线图4.6中跨L/4截面弯矩、剪力、轴力影响线图4.7中跨L/2截面弯矩、剪力、轴力影响线在上述计算出影响线的基础上考虑的荷载横向分布系数，直接进行加载，活载包括人群、汽车。本设计的活载为：人群荷载3.05KN/㎡；汽车采用荷载等级—公路II级。变截面连续箱梁横向分布系数的计算采用经验公式法。公式为K=车道数×横向折减系数×偏载系数=4×1×1.1通过计算本设计的荷载横向分布系数为汽车：4.4。本设计纵向加载采用GQJS程序进行。通过验算表明电算结果具有足够的精度，计算结果可靠。现将各截面（主要控制截面）活载内力列表如下：表4.1汽车最大活载内力将以上内力值用曲线连接得到活载内力图如下：单元号汽车荷载剪力弯矩单元号汽车荷载剪力弯矩1Max剪力15078.979-10517.55327Max剪力3251.007-14136.504Min剪力-13682.4899568.553Min剪力-782.01820320.982Max弯矩-12623.1808827.748Max弯矩-479.02119683.183Min弯矩14052.384-9827.231Min弯矩2276.347-34511.7862Max剪力3283.514-16621.23728Max剪力3092.917-7800.143Min剪力-2059.86326498.380Min剪力-794.14217827.952Max弯矩-1926.78224792.887Max弯矩1033.77719564.139Min弯矩2651.877-27140.010Min弯矩2026.841-27230.204 3Max剪力3197.130-12856.25429Max剪力2933.990-2034.887Min剪力-2060.05322749.577Min剪力-809.18115398.069Max弯矩-1916.79221284.125Max弯矩1040.92119727.707Min弯矩2582.824-21692.566Min弯矩1851.756-20752.8584Max剪力3102.327-9336.17130Max剪力2751.2163884.217Min剪力-2060.84118297.667Min剪力-830.38512708.491Max弯矩-1890.31717136.473Max弯矩1046.69220038.530Min弯矩2477.602-16819.357Min弯矩1577.698-14248.8385Max剪力2891.399-1667.30431Max剪力2567.2229104.527Min剪力-2066.08810343.808Min剪力-856.40110094.271Max弯矩-1780.606-1780.606Max弯矩1055.05720493.151Min弯矩1985.539-7895.397Min弯矩1297.494-8773.7746Max剪力2656.6025917.96032Max剪力2382.16213643.183Min剪力-2078.5462660.200Min剪力-934.17720274.116Max弯矩432.0487706.199Max弯矩1081.91421146.061Min弯矩927.088-1269.759Min弯矩568.450-5520.6427Max剪力2409.71112843.61233Max剪力2196.46617489.923Min剪力-2100.793-4751.011Min剪力-1037.36920169.152Max弯矩2146.23712597.237Max弯矩1702.78922660.920Min弯矩-1926.782-5592.543Min弯矩-264.670-4358.6818Max剪力2160.38518760.01534Max剪力2010.90920717.777Min剪力-2134.573-11904.339Min剪力-1153.83519984.550Max弯矩1884.06518836.068Max弯矩1548.11426150.982Min弯矩-1926.782-13008.967Min弯矩-327.713-5774.7669Max剪力1915.90723435.80935Max剪力1826.67923322.120Min剪力-2180.943-18964.271Min剪力-1283.60819633.869Max弯矩1615.44224000.520Max弯矩1325.40428955.466Min弯矩-1926.782-20408.721Min弯矩-641.325-8151.06910Max剪力1681.42226832.32036Max剪力1645.43025563.612Min剪力-2240.432-26010.369Min剪力-1426.08619575.919Max弯矩1344.21327966.591Max弯矩1098.64131402.339Min弯矩-1926.782-27760.042Min弯矩-641.325-10481.85711Max剪力1460.28428980.20437Max剪力1556.71026106.349Min剪力-2331.255-2963.632Min剪力-1501.53918701.98Max弯矩1073.05230656.026Max弯矩984.30131849.633Min弯矩-1926.782-35066.518Min弯矩-641.325-12084.67212Max剪力1279.31629916.90838Max剪力1384.50027202.319Min剪力-2523.344-6973.742Min剪力-1659.78117732.513Max弯矩837.22131936.061Max弯矩754.73632872.791Min弯矩-1926.782-41426.896Min弯矩-641.325-14564.31813Max剪力1110.73830049.81339Max剪力1220.70527703.748 Min剪力-2722.849-11945.581Min剪力-1826.42016345.504Max弯矩603.46232199.987Max弯矩525.18033112.585Min弯矩-1926.782-47778.237Min弯矩-643.847-16998.80214Max剪力976.30029616.28740Max剪力1067.00227618.502Min剪力-2899.218-17017.692Min剪力-1999.61014418.094Max弯矩405.05331639.998Max弯矩297.10032520.676Min弯矩-1926.782-53186.314Min弯矩-643.847-19388.64915Max剪力851.12428741.42341Max剪力924.42426976.249Min剪力-3080.210-22889.069Min剪力-2177.85011909.392Max弯矩212.81130359.830Max弯矩71.55131095.569Min弯矩-1931.016-58573.297Min弯矩-643.847-21699.55616Max剪力735.11427494.18542Max剪力793.42825795.292Min剪力-3265.575-29597.377Min剪力-2360.0168634.565Max弯矩81.66229421.026Max弯矩-24.14828905.644Min弯矩-2002.926-64031.576Min弯矩-770.508-24140.00717Max剪力710.64930567.79443Max剪力674.00324147.874Min剪力-3455.129-37177.309Min剪力-2545.3374576.956Max弯矩130.16230131.419Max弯矩-84.09226432.353Min弯矩-2169.551-69827.122Min弯矩-929.416-27136.24918Max剪力699.27732710.33744Max剪力565.79322100.091Min剪力-3648.737-45660.882Min剪力-2733.345-324.129Max弯矩279.46731168.929Max弯矩-136.14523646.072Min弯矩-2436.983-76263.270Min弯矩-1092.663-30660.03819Max剪力694.86634202.53145Max剪力479.88720036.781Min剪力-3796.646-52777.861Min剪力-2899.848-5347.085Max弯矩459.10932090.663Max弯矩-164.58520999.692Min弯矩-2705.218-81937.140Min弯矩-1249.784-34222.52920Max剪力4099.004-58932.10046Max剪力401.68117769.421Min剪力-755.54635033.742Min剪力-3068.151-11114.694Max弯矩-701.93232715.625Max弯矩-176.03718216.308Min弯矩3402.739-87202.695Min弯矩-1421.434-38315.55821Max剪力4021.294-53789.97247Max剪力340.42515700.967Min剪力-755.73634065.219Min剪力-3213.833-16631.217Max弯矩-679.43531839.567Max弯矩-171.98815776.586Min弯矩3328.567-80980.729Min弯矩-1580.614-42248.38222Max剪力3921.422-47696.71748Max剪力284.18913547.237Min剪力-756.55832320.964Min剪力-3360.839-22706.770Max弯矩-650.99730239.135Max弯矩-152.47813336.240Min弯矩3211.536-73721.348Min弯矩-1753.714-46633.22123Max剪力3788.090-40141.15749Max剪力232.71311338.179Min剪力-758.72829737.947Min剪力-3509.164-29353.566 Max弯矩-614.44827879.874Max弯矩-119.60710943.125Min弯矩2991.652-64813.598Min弯矩-1938.741-51510.73824Max剪力3654.426-33008.55350Max剪力185.7519102.766Min剪力-762.22527251.572Min剪力-3658.815-36583.395Max弯矩-578.60325647.716Max弯矩-72.5598647.264Min弯矩2837.682-56489.298Min弯矩-2136.618-56924.56125Max剪力3520.387-26298.07451Max剪力167.3785835.115Min剪力-767.17724856.989Min剪力-3809.801-44406.558Max弯矩-543.19323539.974Max弯矩-11.6446496.515Min弯矩2684.146-48601.695Min弯矩-2347.134-62915.71326Max剪力3385.929-20008.04952Max剪力165.4806069.650Min剪力-773.72322548.974Min剪力-3923.993-51001.388Max弯矩-773.72322548.974Max弯矩57.4925777.505Min弯矩2462.378-41305.450Min弯矩-2513.669-68218.4114.2温度次内力计算温度影响主要是由于季节和日照变化引起的梁体的温度变化而引起的梁内力。由于是组连续梁桥，所以整体温变对梁体的内力影响较小，又由于是变高度连续梁，同时有纵坡的影响，整体温变对梁体内力也的影响也不大，此设计中纵坡不大，所以没有考虑纵坡对整体温变影响。所以温度次内力主要考虑上下缘温差的影响。本桥计算箱梁顶板上下缘温差5℃的温度次内力，取а=1.0E-5，则ε=а·t1=-5×10-5，χ=0，各单元均相同。计算结构如下表：表4.2温度次内力（组号1）节点号轴力剪力弯矩节点号轴力剪力弯矩169069.0494518.25-11473627118483.4849.90658575.852118483.4-1771.05-7784.828118483.4849.90638230.82118483.4-1771.058631.2429118483.4849.90618422.814118483.4-1771.05-1486930118483.4849.906-1987.975118483.4-1771.05-16613.931118483.4849.906-19733.66118483.4-1771.05-14825.132118483.4849.906-346017118483.4-1771.05-9789.4633118483.4849.906-48477.78118483.4-1771.05402.62734118483.4849.906-57197.99118483.4-1771.0511585.3835118483.4849.906-62671.210118483.4-1771.0525646.4536118483.4849.906-44652.811118483.4-1771.0542372.6437118483.4849.906-62911.212118483.4-1771.0558956.6238118483.4849.906-54172.213118483.4-1771.0576077.6539118483.4849.906-41899.614118483.4-1771.0592888.0940118483.4849.906-26380.1 15118483.4-1771.05111025.441118483.4849.906-5704.1616118483.4-1771.0513047942118483.4849.90615962.4317118483.4-1771.05151203.643118483.4849.90640507.3418118483.4-1771.05173173.844118483.4849.90667717.3719118483.4-1771.05175334.445118483.4849.90693474.7120118483.4849.906152471.646118483.4849.906119769.121118483.4849.906173722.447118483.4849.906144442.422118483.4849.906169489.248118483.4849.906170442.623118483.4849.906144755.649118483.4849.90619775924118483.4849.906121267.550118483.4849.906226346.625118483.4849.90699050.4951118483.4849.906256179.726118483.4849.90678149.7352118483.4849.906264237.5图4.8运营阶段活载组号1产生的弯矩图表4.3温度次内力（组号2）节点号轴力剪力弯矩节点号轴力剪力弯矩1-17267.3-23629.628683.8927-29620.9-212.477-146442-29620.9442.7631946.19928-29620.9-212.477-9557.72-29620.9442.763-2157.8129-29620.9-212.477-4605.74-29620.9442.7633717.25230-29620.9-212.477496.9935-29620.9442.7634153.46431-29620.9-212.4774933.4096-29620.9442.7633706.28132-29620.9-212.4778650.2447-29620.9442.7632447.36633-29620.9-212.47712119.428-29620.9442.763-100.65734-29620.9-212.47714299.489-29620.9442.763-2896.3535-29620.9-212.47715667.8110-29620.9442.763-6411.6136-29620.9-212.47711163.2111-29620.9442.763-10593.237-29620.9-212.47715727.7912-29620.9442.763-14739.238-29620.9-212.47713543.0413-29620.9442.763-19019.439-29620.9-212.47710474.914-29620.9442.763-2322240-29620.9-212.4776595.02415-29620.9442.763-27756.441-29620.9-212.4771426.04116-29620.9442.763-32619.742-29620.9-212.477-3990.6117-29620.9442.763-37800.943-29620.9-212.477-10126.818-29620.9442.763-43293.544-29620.9-212.477-16929.319-29620.9442.763-43833.645-29620.9-212.477-23368.720-29620.9-212.477-38117.946-29620.9-212.477-29942.321-29620.9-212.477-43430.647-29620.9-212.477-36110.622-29620.9-212.477-42372.348-29620.9-212.477-42610.723-29620.9-212.477-36188.949-29620.9-212.477-49439.8 24-29620.9-212.477-30316.950-29620.9-212.477-56586.625-29620.9-212.477-24762.651-29620.9-212.477-64044.926-29620.9-212.477-19537.452-29620.9-212.477-66059.4图4.9运营阶段活载组号2产生的弯矩图表4.4温度次内力（组号3）节点号轴力剪力弯矩节点号轴力剪力弯矩14939.75815602.89-8205.792711513.558.90928439.33211513.55-13.69112079.792811513.558.90926316.21211513.55-13.69113991.832911513.558.90924081.31411513.55-13.69112025.033011513.558.90921898.6511513.55-13.69112489.113111513.558.90919620.48611513.55-13.69113296.573211513.558.90917601.33711513.55-13.69114419.553311513.558.90915861.89811513.55-13.69116043.63411513.558.90914218.71911513.55-13.69117763.923511513.558.90913076.611011513.55-13.69119763.933611513.558.90912250.021111513.55-13.69122022.933711513.558.90913706.231211513.55-13.69124188.93811513.558.90911784.631311513.55-13.69126407.063911513.558.90912339.111411513.55-13.69128515.844011513.558.90913236.971511513.55-13.69130753.554111513.558.90914450.351611513.55-13.69133119.174211513.558.90916164.811711513.55-13.69135608.34311513.558.90917975.521811513.55-13.69138218.474411513.558.90920065.941911513.55-13.69138784.854511513.558.90922415.342011513.558.90936840.394611513.558.90924660.412111513.558.90938776.484711513.558.90926957.682211513.558.90938199.354811513.558.90929134.252311513.558.90935574.834911513.558.90931439.772411513.558.90933071.355011513.558.90933873.182511513.558.90930691.395111513.558.90936430.122611513.558.90928439.335211513.558.90939108.09 图4.10运营阶段活载组号3产生的弯矩图4.3支座沉降次内力计算由于墩台基础的沉降或人工调整支座位移都可能使连续梁桥产生次内力。本桥在计算过程中，根据墩台基础地质情况并考虑施工因素，按跨中3号支座沉降0.5cm考虑。内力计算结果见下表：表4.5沉降次内力节点号轴力剪力弯矩节点号轴力剪力弯矩132937.0977976.07-53724.85314466-1164.1880480.8214466-3635.71132379.95414466-1164.1880482.78314466-3635.71127224.75514466-1164.1876309.52414466-3635.71117763.35614466-1164.1869696.93514466-3635.71103797.55714466-1164.1863231.85614466-3635.7190226.875814466-1164.1856908.99714466-3635.7177070.545914466-1164.1850737.34814466-3635.7164454.036014466-1164.1844721.65914466-3635.7151961.446114466-1164.1837899.771014466-3635.7139800.126214466-1164.1831243.991114466-3635.7127982.626314466-1164.1823857.441214466-3635.7117819.856414466-1164.1816814.31314466-3635.717823.2826514466-1164.1810116.821414466-3635.71-509.5816614466-1164.183529.4071514466-3635.71-8689.126714466-1164.18-2552.221614466-3635.71-16715.26814466-1164.18-8219.831714466-3635.71-24585.46914466-1164.18-11231.71814466-3635.71-32310.97014466-1164.18-15854.71914466-3635.71-389627114466-1164.18-19934.420144661164.098-47434.67214466-1164.18-23546.921144661164.098-43287.57314466-1164.18-26884.622144661164.098-42103.97414466-1164.18-29618.923144661164.098-41797.17514466-1164.18-32241.124144661164.098-41338.27614466-1164.18-34529.825144661164.098-40730.97714466-1164.18-36461.926144661164.098-39970.47814466-1164.18-37893.127144661164.098-39047.57914466-1164.18-39168.8 28144661164.098-37764.88014466-1164.18-40094.729144661164.098-36271.78114466-1164.18-40865.730144661164.098-34345.18214466-1164.18-41474.731144661164.098-320758314466-1164.18-41928.732144661164.098-29459.68414466-1164.18-42238.133144661164.098-26733.98514466-1164.18-43312.834144661164.098-2350986144663636.099-47455.135144661164.098-1985787144663636.099-38987.136144661164.098-13555.788144663636.099-32257.137144661164.098-13522.289144663636.099-24535.838144661164.098-8288.7190144663636.099-16662.439144661164.098-2588.1491144663636.099-8633.3740144661164.0983387.25892144663636.099-450.36241144661164.0989966.06193144663636.0997948.36242144661164.09816669.5994144663636.09917950.5843144661164.09823704.5195144663636.09928117.1644144661164.09831092.9696144663636.09939946.3345144661164.09837764.1497144663636.09952112.6446144661164.09844594.298144663636.09964614.3247144661164.09850611.5399144663636.09977154.0948144661164.09856780.06100144663636.09990335.6549144661164.09863095.7101144663636.099103881.150144661164.09869565102144663636.099119966.151144661164.09876170.6103144663636.099125118.952144661164.09880483.110432940.11-77983.2102290.7图4.11中墩沉降0.5cm产生的弯矩图4.4荷载组合及内力包络图为了进行钢束估算或截面验算，就需要先确定主梁沿桥跨方向各个截面的控制内力，即将各种荷载引起的最不利内力分别按照一定原则进行组合。4.4.1组合方法公路桥涵设计采用的作用按《公路桥涵设计通用规范》（JTG D62-2004）分永久作用、可变作用和偶然作用三类，设计时考虑结构上可能同时出现的作用，按承载能力极限状态和正常使用极限状态进行作用效应组合，取其最不利效应组合进行设计。按照《公路桥涵设计通用规范》（JTGD62-2004）中4.1.6条规定，公路桥涵结构按承载能力极限状态设计时，考虑基本组合，永久作用的设计值效应与可变作用设计值效应相组合，其效应组合表达式为：(4-1)本设计承载能力极限组合为：=1.2恒载+1.4汽车荷载+1.40.8人群荷载式中——承载能力极限状态下作用基本组合的效应组合设计值；——结构重要性系数，本设计中安全等级为一级，对应系数取1.1：——第i个永久作用效应的分项系数，本设计中的永久作用及其分项系数分别为：混凝土结构自重取1.2；混凝土的收缩及徐变作用取1.0；混凝土基础变位作用取0.5；——第i个永久作用效应的标准值和设计值；——汽车荷载效应（含汽车冲击力、离心力）的分项系数，取=1.4；——汽车荷载效应（含汽车冲击力、离心力）的标准值和设计值；——在作用效应组合中除汽车荷载效应（含汽车冲击力、离心力）、风荷载外的其他第j个可变作用效应的分项系数，本组合中为人群，取=1.4；——在作用效应组合中除汽车荷载效应（含汽车冲击力、离心力）外的其他第j个可变作用效应的标准值和设计值，本组合为人群的标准值和设计值；——在作用效应组合中除汽车荷载效应（含汽车冲击力、离心力）外的其他可变作用效应的组合系数，当永久作用与汽车荷载和人群荷载组合时，人群荷载的组合系数取=0.8。 公路桥涵结构按正常使用极限状态设计时，采用以下两种效应组合：（1）作用短期效应组合。永久作用标准值效应与可变作用频遇值效应相组合，其效应组合表达式为：（4-2）本设计作用短期效应组合为：=恒载+0.7汽车荷载+人群荷载+沉降荷载+0.8温度荷载式中——作用短期效应组合设计值；——第j个可变作用效应的频遇值系数，汽车荷载（不计冲击力）=0.7，人群荷载=1.0，温度梯度作用=0.8；——第j个可变作用效应的频遇值。（2）作用长期效应组合。永久作用标准值效应与可变作用准永久值效应相组合，其效应组合表达式为：(4-3)本设计作用长期效应组合为：=恒载+0.4（汽车荷载+人群荷载）+沉降荷载+0.8温度荷载式中——作用短期效应组合设计值；——第j个可变作用效应的准永久值系数，汽车荷载（不计冲击力）=0.4，人群荷载=0.4，温度梯度作用=0.8；——第j个可变作用效应的准永久值。4.4.2计算结果M_Vmax──在作用效应组合方案信息中选择②公桥规JTG-D60-2004第4.1.7条正常使用极限状态效应组合时，由作用效应组合和预应力产生的最大剪力相应的弯矩。M_Vmin──在作用效应组合方案信息中选择②公桥规JTG-D60-2004第4.1.7条正常使用极限状态效应组合时，由作用效应组合和预应力产生的最小剪力相应的弯矩。 V_Mmax──在作用效应组合方案信息中选择②公桥规JTG-D60-2004第4.1.7条正常使用极限状态效应组合时，由作用效应组合和预应力产生的最大弯矩相应的剪力。V_Mmin──在作用效应组合方案信息中选择②公桥规JTG-D60-2004第4.1.7条正常使用极限状态效应组合时，由作用效应组合和预应力产生的最小弯矩相应的剪力。基本组合结果，作用长期效应组合和作用短期效应组合结果分别见表4.7，表4.8。表4.6基本组合效应(单位：剪力(kN)、弯矩(kN.m))运营阶段(活载)组合应力荷载组合1上下缘计算书单元节点上缘最大应力上缘最小应力下缘最大应力下缘最小应力110.3443-0.38321.6649-1.4956123.1476-1.10151.1153-5.1952214.0012-1.22824.2516-6.3244223.7569-0.32212.4778-6.1428311.9208-0.19060.6477-1.6868321.73060.07160.3519-1.4858413.29160.20041.3824-5.3809421.55130.24831.0016-0.7702511.55130.24831.0016-0.7702520.2398-0.34131.88070.9794610.2398-0.34131.88070.979462-0.8199-1.85213.9772.404471-0.8199-1.85213.9772.404472-2.0313-3.73776.24083.864181-2.0313-3.73776.24083.864182-3.3857-5.54078.23175.385491-3.3857-5.54078.23175.385492-4.8157-7.24629.90236.8481101-4.8157-7.24629.90236.8481102-6.1183-8.621410.90737.9272111-6.1183-8.621410.90737.9272112-7.3417-9.871411.86098.9633121-7.3417-9.871411.86098.9633122-8.1461-10.526112.04429.4179131-8.1461-10.526112.04429.4179132-9.0662-11.378612.57710.0956141-9.0662-11.378612.57710.0956142-9.9632-12.185613.03510.7139 151-9.9632-12.185613.03510.7139152-10.7652-12.939413.41711.2686161-10.7652-12.939413.41711.2686162-11.5111-13.648813.739211.6836171-11.5111-13.648813.739211.6836172-14.3586-16.837422.781519.5348181-14.3586-16.837422.781519.5348182-9.5151-11.082512.727110.9774191-9.5151-11.082512.727110.9774192-7.562-8.7679.24218.0047201-7.562-8.7679.24218.0047202-9.6138-11.181712.756811.0182211-9.6138-11.181712.756811.0182212-14.9035-17.396322.924519.7474221-14.9035-17.396322.924519.7474222-13.4609-15.777122.00718.8942231-13.4609-15.777122.00718.8942232-12.0659-14.210221.019117.9809241-12.0659-14.210221.019117.9809242-9.6922-11.482512.130110.3612251-9.6922-11.482512.130110.3612252-8.8713-10.576211.56069.8362261-8.8713-10.576211.56069.8362262-8.0179-9.624210.90799.2402271-8.0179-9.624210.90799.2402272-7.1766-8.776110.43988.7185281-7.1766-8.776110.43988.7185282-5.8846-7.42819.33997.645291-5.8846-7.42819.33997.645292-4.3965-5.92178.08066.3837301-4.3965-5.92178.08066.3837302-2.6892-4.18026.2854.6304311-2.6892-4.18026.2854.6304312-0.9129-2.50954.27722.6122321-0.9129-2.50954.27722.61223220.8027-0.85242.34470.26223310.8027-0.85242.34470.26223322.58940.52840.5509-2.23213412.58940.52840.5509-2.23213424.10821.6104-0.855-4.48113514.10821.6104-0.855-4.48113524.9812.0376-1.4887-5.8348 3613.2581.2582-0.9588-3.23433623.24171.1435-0.8279-3.21623714.95661.8689-1.2385-5.80083723.99040.80340.3234-4.31833813.99040.80340.3234-4.31833822.386-0.75772.5017-1.9583912.386-0.75772.5017-1.9583920.5237-2.45724.73370.63044010.5237-2.45724.73370.6304402-1.4726-4.27746.82353.171411-1.4726-4.27746.82353.171412-3.4881-5.98568.66625.4625421-3.4881-5.98568.66625.4625422-5.4072-7.618310.2347.4111431-5.4072-7.618310.2347.4111432-7.0376-8.963211.20318.7844441-7.0376-8.963211.20318.7844442-8.4457-10.193512.10969.9385451-8.4457-10.193512.10969.9385452-9.3346-10.872512.332510.4554461-9.3346-10.872512.332510.4554462-10.2947-11.730912.847911.1185471-10.2947-11.730912.847911.1185472-11.1956-12.550113.293511.6893481-11.1956-12.550113.293511.6893482-13.8002-15.295622.726320.2899491-13.8002-15.295622.726320.2899492-15.1276-16.616623.462621.1492501-15.1276-16.616623.462621.1492502-16.4576-17.95724.131121.9127511-16.4576-17.95724.131121.9127512-10.587-11.527113.345712.1553521-10.587-11.527113.345712.1553522-8.3407-9.07999.65628.8023531-8.3407-9.07999.65628.8023532-10.587-11.527113.345712.1553541-10.587-11.527113.345712.1553542-16.4576-17.95724.13121.9126551-16.4576-17.95724.13121.9126552-15.1276-16.616623.462621.1492561-15.1276-16.616623.462621.1492562-13.8001-15.295522.726220.2898 571-13.8001-15.295522.726220.2898572-11.1955-12.5513.293511.6893581-11.1955-12.5513.293511.6893582-10.2946-11.730812.847811.1184591-10.2946-11.730812.847811.1184592-9.3346-10.872512.332510.4554601-9.3346-10.872512.332510.4554602-8.4458-10.193612.10979.9386611-8.4458-10.193612.10979.9386612-7.0379-8.963511.20348.7847621-7.0379-8.963511.20348.7847622-5.4074-7.618510.23437.4114631-5.4074-7.618510.23437.4114632-3.4884-5.98598.66655.4628641-3.4884-5.98598.66655.4628642-1.4728-4.27766.82383.1713651-1.4728-4.27766.82383.17136520.5235-2.45744.73390.63066610.5235-2.45744.73390.63066622.3858-0.75792.5019-1.95786712.3858-0.75792.5019-1.95786723.99030.80330.3235-4.31826813.99030.80330.3235-4.31826824.95661.8689-1.2384-5.80076913.24161.1434-0.8279-3.21626923.2581.2582-0.9588-3.23437014.98092.0375-1.4887-5.83487024.10821.6104-0.855-4.48117114.10821.6104-0.855-4.48117122.58950.52850.5507-2.23237212.58950.52850.5507-2.23237220.8029-0.8022.34450.2627310.8029-0.8022.34450.262732-0.9127-2.50934.27682.6119741-0.9127-2.50934.27682.6119742-2.689-4.186.28474.6302751-2.689-4.186.28474.6302752-4.3963-5.92158.08036.3834761-4.3963-5.92158.08036.3834762-5.8844-7.42799.33957.6447771-5.8844-7.42799.33957.6447772-7.1765-8.77610.43978.7184 781-7.1765-8.77610.43978.7184782-8.0179-9.624210.90799.2402791-8.0179-9.624210.90799.2402792-8.8714-10.576311.56079.8363801-8.8714-10.576311.56079.8363802-9.6923-11.482612.130210.3613811-9.6923-11.482612.130210.3613812-12.066-14.210321.019217.981821-12.066-14.210321.019217.981822-13.4609-15.777122.007118.8943831-13.4609-15.777122.007118.8943832-14.9035-17.396322.924619.7475841-14.9035-17.396322.924619.7475842-9.6138-11.181712.756911.0183851-9.6138-11.181712.756911.0183852-7.562-8.7679.24218.0047861-7.562-8.7679.24218.0047862-9.5151-11.082512.727110.9774871-9.5151-11.082512.727110.9774872-14.3586-16.837422.781519.5348881-14.3586-16.837422.781519.5348882-11.5111-13.648813.739211.6836891-11.5111-13.648813.739211.6836892-10.7652-12.939413.416911.2685901-10.7652-12.939413.416911.2685902-9.9631-12.185513.034910.7138911-9.9631-12.185513.034910.7138912-9.0661-11.378512.576910.0955921-9.0661-11.378512.576910.0955922-8.146-10.52612.04429.4179931-8.146-10.52612.04429.4179932-7.3418-9.871511.8618.9634941-7.3418-9.871511.8618.9634942-6.1185-8.621610.90757.9274951-6.1185-8.621610.90757.9274952-4.8159-7.24649.90266.8484961-4.8159-7.24649.90266.8484962-3.3858-5.54088.23195.3856971-3.3858-5.54088.23195.3856972-2.0315-3.73796.2413.8643981-2.0315-3.73796.2413.8643982-0.8199-1.85213.97712.4045 991-0.8199-1.85213.97712.40459920.2398-0.34131.88070.979410010.2398-0.34131.88070.979410021.55140.24841.0015-0.770310111.55140.24841.0015-0.770310123.29190.20071.3818-5.381510211.73070.07170.3518-1.485910221.9209-0.19050.6475-1.68710313.7572-0.32182.4772-6.143410324.0016-1.22784.2508-6.325210413.148-1.10111.1145-5.19610420.3443-0.38321.6649-1.4956表4.7基本组合效应(单位：剪力(kN)、弯矩(kN.m))运营阶段(活载)组合应力荷载组合2上下缘计算书单元节点上缘最大应力上缘最小应力下缘最大应力下缘最小应力110.3443-4.857621.1029-1.49561215.437-1.10151.1153-15.51882111.622-1.228214.2417-6.32442211.0899-0.322113.1691-6.1428315.3684-0.19063.2024-1.6868325.00280.07163.1023-1.48584110.36010.200412.7662-5.3809428.65660.248310.9854-0.7702518.65660.248310.9854-0.7702527.3361-0.341311.33790.9794617.3361-0.341311.33790.9794626.4005-1.852112.59922.4044716.4005-1.852112.59922.4044725.61-3.737713.83053.8641815.61-3.737713.83053.8641824.4846-5.540714.79735.3854914.4846-5.540714.79735.3854923.2846-7.246215.47856.84811013.2846-7.246215.47856.84811021.7702-8.621415.26077.92721111.7702-8.621415.26077.92721120.6863-9.871415.52748.96331210.6863-9.871415.52748.9633122-0.679-10.526114.74939.4179131-0.679-10.526114.74939.4179 132-1.5473-11.378614.846610.0956141-1.5473-11.378614.846610.0956142-2.4106-12.185614.915510.7139151-2.4106-12.185614.915510.7139152-3.1958-12.939414.951111.2686161-3.1958-12.939414.951111.2686162-3.9409-13.648814.966311.6836171-3.9409-13.648814.966311.6836172-6.2159-16.837422.781518.4485181-6.2159-16.837422.781518.4485182-4.9668-11.082512.727110.4249191-4.9668-11.082512.727110.4249192-4.5449-8.7679.24217.9163201-4.5449-8.7679.24217.9163202-5.0618-11.181712.756810.4788211-5.0618-11.181712.756810.4788212-6.6962-17.396322.924518.7109221-6.6962-17.396322.924518.7109222-5.5142-15.777122.00718.3626231-5.5142-15.777122.00718.3626232-4.378-14.210221.055717.9809241-4.378-14.210221.055717.9809242-2.5111-11.482514.424510.3612251-2.5111-11.482514.424510.3612252-1.8199-10.576214.34869.8362261-1.8199-10.576214.34869.8362262-1.1295-9.624214.25779.2402271-1.1295-9.624214.25779.24022720.0805-8.776114.98398.71852810.0805-8.776114.98398.71852821.0509-7.428114.80167.6452911.0509-7.428114.80167.6452922.4756-5.921715.13966.38373012.4756-5.921715.13966.38373023.6591-4.180214.75414.63043113.6591-4.180214.75414.63043124.8639-2.509514.28592.61223214.8639-2.509514.28592.61223225.8243-0.852413.98220.26223315.8243-0.852413.98220.26223327.07090.528413.7109-2.23213417.07090.528413.7109-2.2321 3428.17051.610413.5502-4.48113518.17051.610413.5502-4.48113528.84712.037613.6279-5.83483614.15721.25824.4983-3.23433624.22191.14354.5367-3.21623718.9421.868913.7013-5.80083728.62280.803413.8961-4.31833818.62280.803413.8961-4.31833827.8254-0.757714.2984-1.9583917.8254-0.757714.2984-1.9583926.8142-2.457214.62440.63044016.8142-2.457214.62440.63044025.8428-4.277414.83653.1714115.8428-4.277414.83653.1714124.571-5.985615.00965.46254214.571-5.985615.00965.46254223.2906-7.618315.12527.41114313.2906-7.618315.12527.41114321.7488-8.963214.57228.78444411.7488-8.963214.57228.78444420.6889-10.193514.61079.93854510.6889-10.193514.61079.9385452-0.6459-10.872513.785910.4554461-0.6459-10.872513.785910.4554462-1.4564-11.730913.80611.1185471-1.4564-11.730913.80611.1185472-2.2499-12.550113.830311.6893481-2.2499-12.550113.830311.6893482-4.1374-15.295622.726317.5024491-4.1374-15.295622.726317.5024492-5.2313-16.616623.462617.9198501-5.2313-16.616623.462617.9198502-6.3402-17.95724.131118.3088511-6.3402-17.95724.131118.3088512-4.8656-11.527113.345710.2686521-4.8656-11.527113.345710.2686522-4.4251-9.07999.65627.7737531-4.4251-9.07999.65627.7737532-4.8656-11.527113.345710.2686541-4.8656-11.527113.345710.2686542-6.3402-17.95724.13118.3087551-6.3402-17.95724.13118.3087 552-5.2313-16.616623.462617.9198561-5.2313-16.616623.462617.9198562-4.1373-15.295522.726217.5023571-4.1373-15.295522.726217.5023572-2.2498-12.5513.830311.6893581-2.2498-12.5513.830311.6893582-1.4563-11.730813.805911.1184591-1.4563-11.730813.805911.1184592-0.6459-10.872513.785910.4554601-0.6459-10.872513.785910.45546020.6888-10.193614.61089.93866110.6888-10.193614.61089.93866121.7485-8.963514.57268.78476211.7485-8.963514.57268.78476223.2904-7.618515.12557.41146313.2904-7.618515.12557.41146324.5707-5.985915.00995.46286414.5707-5.985915.00995.46286425.8426-4.277614.83683.17136515.8426-4.277614.83683.17136526.814-2.457414.62460.63066616.814-2.457414.62460.63066627.8252-0.757914.2986-1.95786717.8252-0.757914.2986-1.95786728.62270.803313.8962-4.31826818.62270.803313.8962-4.31826828.9421.868913.7014-5.80076914.22181.14344.5367-3.21626924.15721.25824.4983-3.23437018.8472.037513.6279-5.83487028.17051.610413.5502-4.48117118.17051.610413.5502-4.48117127.0710.528513.7107-2.23237217.0710.528513.7107-2.23237225.8245-0.80213.9820.2627315.8245-0.80213.9820.2627324.8641-2.509314.28562.61197414.8641-2.509314.28562.61197423.6593-4.1814.75384.63027513.6593-4.1814.75384.63027522.4758-5.921515.13926.38347612.4758-5.921515.13926.3834 7621.0511-7.427914.80137.64477711.0511-7.427914.80137.64477720.0807-8.77614.98388.71847810.0807-8.77614.98388.7184782-1.1295-9.624214.25779.2402791-1.1295-9.624214.25779.2402792-1.82-10.576314.34879.8363801-1.82-10.576314.34879.8363802-2.5112-11.482614.424610.3613811-2.5112-11.482614.424610.3613812-4.3781-14.210321.055817.981821-4.3781-14.210321.055817.981822-5.5142-15.777122.007118.3627831-5.5142-15.777122.007118.3627832-6.6962-17.396322.924618.711841-6.6962-17.396322.924618.711842-5.0618-11.181712.756910.4789851-5.0618-11.181712.756910.4789852-4.5449-8.7679.24217.9163861-4.5449-8.7679.24217.9163862-4.9668-11.082512.727110.4249871-4.9668-11.082512.727110.4249872-6.2159-16.837422.781518.4485881-6.2159-16.837422.781518.4485882-3.9409-13.648814.966311.6836891-3.9409-13.648814.966311.6836892-3.1958-12.939414.95111.2685901-3.1958-12.939414.95111.2685902-2.4105-12.185514.915410.7138911-2.4105-12.185514.915410.7138912-1.5472-11.378514.846510.0955921-1.5472-11.378514.846510.0955922-0.6789-10.52614.74939.4179931-0.6789-10.52614.74939.41799320.6862-9.871515.52758.96349410.6862-9.871515.52758.96349421.77-8.621615.26097.92749511.77-8.621615.26097.92749523.2844-7.246415.47886.84849613.2844-7.246415.47886.84849624.4845-5.540814.79755.38569714.4845-5.540814.79755.3856 9725.6098-3.737913.83073.86439815.6098-3.737913.83073.86439826.4005-1.852112.59932.40459916.4005-1.852112.59932.40459927.3361-0.341311.33790.979410017.3361-0.341311.33790.979410028.65670.248410.9853-0.770310118.65670.248410.9853-0.7703101210.36040.200712.7656-5.381510215.00290.07173.1022-1.485910225.3685-0.19053.2022-1.687103111.0902-0.321813.1685-6.1434103211.6224-1.227814.2409-6.3252104115.4374-1.10111.1145-15.519610420.3443-4.857621.1029-1.4956表4.8基本组合效应(单位：剪力(kN)、弯矩(kN.m))运营阶段(活载)组合应力荷载组合3上下缘计算书单元节点上缘最大应力上缘最小应力下缘最大应力下缘最小应力111.4628-0.38321.6649-6.3551123.1476-4.17393.6962-5.1952214.0012-3.13344.2516-8.8219223.7569-2.15532.4778-8.8156311.9208-1.05250.6477-2.3255321.7306-0.74650.3519-2.1734413.2916-1.56671.3824-8.2268421.5513-1.5281.0016-3.2661511.5513-1.5281.0016-3.2661520.2398-2.11541.8807-1.3849610.2398-2.11541.8807-1.384962-0.8199-3.65723.9770.248971-0.8199-3.65723.9770.248972-2.0313-5.6486.24081.966681-2.0313-5.6486.24081.966682-3.3857-7.50838.23173.74491-3.3857-7.50838.23173.74492-4.8157-9.27129.90235.454101-4.8157-9.27129.90235.454102-6.1183-10.593510.90736.8388111-6.1183-10.593510.90736.8388112-7.3417-11.878411.86098.0467 121-7.3417-11.878411.86098.0467122-8.1461-12.392912.04428.7416131-8.1461-12.392912.04428.7416132-9.0662-13.258312.5779.5282141-9.0662-13.258312.5779.5282142-9.9632-14.073713.03510.2438151-9.9632-14.073713.03510.2438152-10.7652-14.831713.41710.885161-10.7652-14.831713.41710.885162-11.5111-15.541413.739211.3768171-11.5111-15.541413.739211.3768172-14.3586-18.87323.053119.5348181-14.3586-18.87323.053119.5348182-9.5151-12.219612.865210.9774191-9.5151-12.219612.865210.9774192-7.562-9.52129.26428.0047201-7.562-9.52129.26428.0047202-9.6138-12.319712.891611.0182211-9.6138-12.319712.891611.0182212-14.9035-19.448123.183719.7474221-14.9035-19.448123.183719.7474222-13.4609-17.763822.139918.8942231-13.4609-17.763822.139918.8942232-12.0659-16.132221.019117.9718241-12.0659-16.132221.019117.9718242-9.6922-13.277812.13019.7876251-9.6922-13.277812.13019.7876252-8.8713-12.339111.56069.1393261-8.8713-12.339111.56069.1393262-8.0179-11.346310.90798.4027271-8.0179-11.346310.90798.4027272-7.1766-10.590410.43987.5824281-7.1766-10.590410.43987.5824282-5.8846-9.1629.33996.2796291-5.8846-9.1629.33996.2796292-4.3965-7.63978.08064.619301-4.3965-7.63978.08064.619302-2.6892-5.76736.2852.5132311-2.6892-5.76736.2852.5132312-0.9129-3.95374.27720.11321-0.9129-3.95374.27720.113220.8027-2.10782.3447-2.6471 3310.8027-2.10782.3447-2.64713322.5894-0.5920.5509-5.52213412.5894-0.5920.5509-5.52213424.10820.5948-0.855-8.08233514.10820.5948-0.855-8.08233524.9811.0711-1.4887-9.6143613.2581.0334-0.9588-4.59863623.24170.8985-0.8279-4.55743714.95660.8726-1.2385-9.53573723.9904-0.35470.3234-7.71153813.9904-0.35470.3234-7.71153822.386-2.11752.5017-4.90723912.386-2.11752.5017-4.90723920.5237-4.02984.7337-1.84234010.5237-4.02984.7337-1.8423402-1.4726-6.10636.82351.1678411-1.4726-6.10636.82351.1678412-3.4881-8.00048.66623.8767421-3.4881-8.00048.66623.8767422-5.4072-9.792710.2346.1883431-5.4072-9.792710.2346.1883432-7.0376-11.159811.20317.9421441-7.0376-11.159811.20317.9421442-8.4457-12.477212.10969.3133451-8.4457-12.477212.10969.3133452-9.3346-13.044712.332510.092461-9.3346-13.044712.332510.092462-10.2947-13.940512.847910.8789471-10.2947-13.940512.847910.8789472-11.1956-14.786513.293511.5551481-11.1956-14.786513.293511.5551482-13.8002-17.711323.423220.2899491-13.8002-17.711323.423220.2899492-15.1276-19.090724.269921.1492501-15.1276-19.090724.269921.1492502-16.4576-20.486425.032121.9127511-16.4576-20.486425.032121.9127512-10.587-12.957513.817312.1553521-10.587-12.957513.817312.1553522-8.3407-10.05889.91338.8023531-8.3407-10.05889.91338.8023532-10.587-12.957513.817312.1553 541-10.587-12.957513.817312.1553542-16.4576-20.486425.03221.9126551-16.4576-20.486425.03221.9126552-15.1276-19.090724.269921.1492561-15.1276-19.090724.269921.1492562-13.8001-17.711223.423120.2898571-13.8001-17.711223.423120.2898572-11.1955-14.786413.293511.5551581-11.1955-14.786413.293511.5551582-10.2946-13.940412.847810.8788591-10.2946-13.940412.847810.8788592-9.3346-13.044712.332510.092601-9.3346-13.044712.332510.092602-8.4458-12.477312.10979.3134611-8.4458-12.477312.10979.3134612-7.0379-11.160111.20347.9424621-7.0379-11.160111.20347.9424622-5.4074-9.792910.23436.1886631-5.4074-9.792910.23436.1886632-3.4884-8.00078.66653.877641-3.4884-8.00078.66653.877642-1.4728-6.10656.82381.1681651-1.4728-6.10656.82381.16816520.5235-4.034.7339-1.84216610.5235-4.034.7339-1.84216622.3858-2.11772.5019-4.9076712.3858-2.11772.5019-4.9076723.9903-0.35480.3235-7.71146813.9903-0.35480.3235-7.71146824.95660.8726-1.2384-9.53566913.24160.8984-0.8279-4.55746923.2581.0334-0.9588-4.59867014.98091.071-1.4887-9.6147024.10820.5948-0.855-8.08237114.10820.5948-0.855-8.08237122.5895-0.59190.5507-5.52237212.5895-0.59190.5507-5.52237220.8029-2.05742.3445-2.64737310.8029-2.05742.3445-2.6473732-0.9127-3.95354.27680.1097741-0.9127-3.95354.27680.1097742-2.689-5.76716.28472.5129 751-2.689-5.76716.28472.5129752-4.3963-7.63958.08034.6187761-4.3963-7.63958.08034.6187762-5.8844-9.16189.33956.2793771-5.8844-9.16189.33956.2793772-7.1765-10.590310.43977.5824781-7.1765-10.590310.43977.5824782-8.0179-11.346310.90798.4027791-8.0179-11.346310.90798.4027792-8.8714-12.339211.56079.1394801-8.8714-12.339211.56079.1394802-9.6923-13.277912.13029.7877811-9.6923-13.277912.13029.7877812-12.066-16.132321.019217.9719821-12.066-16.132321.019217.9719822-13.4609-17.763822.1418.8943831-13.4609-17.763822.1418.8943832-14.9035-19.448123.183819.7475841-14.9035-19.448123.183819.7475842-9.6138-12.319712.891711.0183851-9.6138-12.319712.891711.0183852-7.562-9.52129.26428.0047861-7.562-9.52129.26428.0047862-9.5151-12.219612.865210.9774871-9.5151-12.219612.865210.9774872-14.3586-18.87323.053119.5348881-14.3586-18.87323.053119.5348882-11.5111-15.541413.739211.3768891-11.5111-15.541413.739211.3768892-10.7652-14.831713.416910.8849901-10.7652-14.831713.416910.8849902-9.9631-14.073613.034910.2437911-9.9631-14.073613.034910.2437912-9.0661-13.258212.57699.5281921-9.0661-13.258212.57699.5281922-8.146-12.392812.04428.7416931-8.146-12.392812.04428.7416932-7.3418-11.878511.8618.0468941-7.3418-11.878511.8618.0468942-6.1185-10.593710.90756.839951-6.1185-10.593710.90756.839952-4.8159-9.27149.90265.4543 961-4.8159-9.27149.90265.4543962-3.3858-7.50848.23193.7442971-3.3858-7.50848.23193.7442972-2.0315-5.64826.2411.9668981-2.0315-5.64826.2411.9668982-0.8199-3.65723.97710.249991-0.8199-3.65723.97710.2499920.2398-2.11541.8807-1.384910010.2398-2.11541.8807-1.384910021.5514-1.52791.0015-3.266210111.5514-1.52791.0015-3.266210123.2919-1.56641.3818-8.227410211.7307-0.74640.3518-2.173510221.9209-1.05240.6475-2.325710313.7572-2.1552.4772-8.816210324.0016-3.1334.2508-8.822710413.148-4.17353.6954-5.19610421.4628-0.38321.6649-6.35514.4.3内力包络图根据以上计算出的承载能力极限状态组合和正常使用极限状态组合，分别沿梁轴的各个截面处，将所采用的控制设计内力值按适当的比例尺绘成纵坐标，连接这些坐标点绘成相应的内力包络图。内力包络图主要用来配置预应力钢束，并进行截面承载能力验算。按包络图所反映的内容可分为弯矩包络图和剪力包络图，按内力组合形式可分为承载能力极限状态内力包络图和正常使用极限状态包络图。承载能力极限状态弯矩、剪力包络图分别见图4-16、4-17，正常使用极限状态弯矩、剪力包络图分别见图4-18、图4-19、图4-20、图4-21。图4.12承载能力极限状态弯矩包络图图4.13承载能力极限状态剪力包络图 图4.14正常使用极限状态弯矩包络图图4.15正常使用极限状态剪力包络图 第五章预应力钢束估算与布置5.1钢束估算5.1.1估算原理钢束估算的原理与方法：根据“桥规”规定，预应力梁应按使用阶段的应力要求和承载能力极限状态的强度要求来估算钢束数量，首先根据结构的使用性能要求确定预应力钢筋的数量，然后再由构件的承载能力极限状态要求，确定普通钢筋数量。换句话说，预应力混凝土梁钢筋数量估算的基本原则是按结构使用性能要求确定预应力钢筋数量，极限承载力的不足部分由普通钢筋来补充。全预应力混凝土构件，在作用（或荷载）短期效应组合下，应满足的要求。为在荷载短期效应组合作用下，构件控制截面边缘的法向拉应力，为混凝土的有效预压力，在初步设计时，和可按下列近似公式计算：(5-1-2)(5-1-2)式中：A、W——构件截面面积和对截面受拉边缘的弹性抵抗矩，在设计时均可采用混凝土毛截面计算；——预应力钢筋重心对混凝土截面重心的偏心矩，值可预先假定。将、的计算式代入求得满足全预应力混凝土构件正截面抗裂性要求的有效预加力为：(5-1-3)求得有效预加力后，所需预应力钢筋截面面积按下式计算： (5-1-4)式中：——预应力钢筋的张拉控制应力；——预应力损失总值，估算时对先张拉法构件可取20%～30%的张拉控制应力；对后张法构件可取25%～35%的张拉控制应力，采用低松弛钢筋时取低值。5.1.2钢束估算结果求得预应力钢筋截面面积后，应结合锚具选型和构造要求，选择预应力钢筋束的数量及组成，布置预应力钢筋束并计算其合力作用点至截面边缘的距离。通过计算各截面的纵向配束面积列如下表（考虑到对称布置故只列出一半截面的纵向配束面积）：表5.1钢束估算承载能力极限状态正常使用极限状态单元号截面上缘(根)截面下缘(根)截面上缘(根)截面下缘(根)163083226288323628832410281232516281628618241628718241624820202020920162416102412281211288328123243641336040014400440154404801648052017520560185606001956060020560600215606002252056023480400 244404802540044026360400273203602828032029244284302082483116122012321216161633820122034820122035420820364204203742082038816121639812121240128168411642044220024043240280442803204532036046360400474004404844048049480520505205605156060052560600钢束设计采用15股（顶板束）、12股（底板束）两种不同股数钢绞线，对应锚具采用OVM-15、OVM-12型锚具，对应波纹管采用φ100mm和φ90mm波纹管。钢束具体布置见钢束布置图5.2横向预应力布置横向预应力筋采用中交新预应力筋：270K级钢绞线，公称直径15.2mm，公称面积140mm2，抗拉标准强度为1860MPa。顶板桥面横向预应力筋采用扁锚BM15-3锚具，单向张拉，沿箱梁轴线两侧交叉进行。单根刚铰线的张拉控制力为195 kN。在横隔梁内非桥面横向预应力束采用OVM15-3锚具，两端同时张拉，张拉控制力为586kN。通过对桥面板的分析计算，并按照规范给定的公式进行组合，得到控制设计的弯矩为=76.53kN.m；=-121.74kN.m。预应力混凝土规定为满足抗裂要求所需的有效预加力为：(5-2-1)5.3竖向预应力布置竖向预应力等效为箍筋进行计算，设计剪力值按规范选定，计算结果大于构造要求时采用构造要求，本设计选取边跨边支点及中支点进行分析，经计算边跨边支点附近采用构造配置，中支点附近采用计算结果配置。竖向预应力钢筋采用φ25mm精轧螺纹钢筋，每根粗钢筋设计张拉控制应=0.9*785=706.5MPa，张拉力346.6kN，近似按全部粗钢筋有效拉应力0.7。粗钢筋纵向布置间距在墩附近为50厘米，边墩附近为100厘米，横向每侧腹板1根共2根，则每延米竖向预加力F=4*0.7*346.6=970.48kN。5.4预应力损失及有效预应力计算设计预应力混凝土受弯构件时，需要事先根据承受外荷载情况，估计其预加应力的大小。但是，由于施工因素、材料性能和环境条件的影响，钢筋中的预应力将要减少。这种减少的预应力就是预应力损失。设计中所需的钢筋预应力值，应是扣除相应阶段的应力损失后，钢筋中实际存余的预应力（即有效预应力σy）值。即：σy=σk-σs（5-4-1）5.4.1预应力损失及有效预应力计算方法本设计应力张拉方法采用后张法，且采用超张拉技术，预应力主要有以下五种损失：1、预应力筋与管道壁间摩擦引起的应力损失（σsl）后张法的预应力筋，一般由直线和曲线两部分组成。张拉时，预应力筋沿管道壁滑移而产生摩擦力，使钢筋中的预拉应力形成在张拉端高，向跨中方向逐渐减小的情况。钢筋在任意两截面间的应力值，就是此两截面间由摩擦引起的预应力损失值。此项损失中包含的影响因素主要有：a、弯道影响引起的摩擦力；b、管道偏差影响引起的摩擦力。此项损失的计算公式为： （5-4-2）式中：Ay——预应力钢筋的截面面积；σk——锚下张拉控制应力，σk=Nk/Ay，Nk为锚下张拉控制拉力；θ——曲线包角，以弧度计；x——从张拉端至计算截面的管道长度在构件纵轴上的投影长度，以m计；k——管道偏差系数；μ——钢筋与管道壁之间的摩擦系数；β——计算系数，β=；本设计采用预埋塑料波纹管成型,取管道摩擦系数为=0.15,=0.0015．现以顶板束A7至18号支点截面的摩擦损失为例进行计算，其余钢束均按此法计算。SB1钢束对85号截面的弯起角为12°=0.2093rad，故SB1对85号截面的摩擦损失为：2、锚具变形、钢筋回缩和接缝压缩引起的应力损失（σs2）后张法构件，当张拉结束并进行锚固时，锚具将受到巨大的压力，使锚具自身及锚下垫板压密而变形，同时有些预应力筋束还要向内回缩；此外，拼装式构件的接缝，在锚固后也将继续被压密而变形，所有这些变形都将使锚固后的预应力筋束缩短，因而引起预应力损失，用σs2表示，计算式如下：(5-4-3)式中：——锚具变形、钢筋回缩和接缝压缩值之和（以mm计）；——预应力钢束的有效长度（以mm计）；Ey——预应力筋束的弹性模量。取顶板束T4计算，=24m,=0.012m（采用OVM锚具）3预应力混凝土构件，由混凝土弹性压缩引起的预应力损失可按下列规定计算：后张法预应力混凝土构件当采用分批张拉时，先张拉的钢筋由张拉后批钢筋所引起的混凝土弹性压缩的预应力损失，可按下式计算：(5-4-4)式中—— 在计算截面先张拉的钢筋重心处，由后张拉各批钢筋产生的混凝土法向应力（MPa）；——预应力钢筋弹性模量与混凝土弹性模量的比值。本设计中=5.493，24号截面有通过束48束，面积为0.1198㎡，控制张拉应力为1395Mpa，4预应力钢筋由于钢筋松弛引起的预应力损失终极值，可按下列规定计算：预应力钢丝、钢绞线(5-4-5)式中——张拉系数，一次张拉时，=1.0；超张拉时，=0.9；——钢筋松弛系数，I级松弛（普通松弛），=1.0；II级松弛（低松弛），=0.3；——传力锚固时的钢筋应力，对后张法构件；对先张法构件，。5由混凝土收缩、徐变引起的构件受拉区和受压区预应力钢筋的预应力损失，可按下列公式计算：(5-4-6)(5-4-7)(5-4-8)(5-4-9) (5-4-10)式中——构件受拉区、受压区全部纵向钢筋截面重心处由混凝土收缩、徐变引起的预应力损失；——构件受拉区、受压区全部纵向钢筋截面重心处由预应力产生的混凝土法向压应力（MPa），应按《公路桥规》第6.1.5条和第6.1.6条规定计算。此时，预应力损失值仅考虑预应力钢筋锚固时的损失；——预应力钢筋的弹性模量——预应力钢筋弹性模量与混凝土弹性模量的比值；——构件受拉区、受压区全部纵向钢筋配筋率；——构件截面面积，对先张法构件，；对后张法构件。此处，为换算截面，为净截面；——截面回转半径，，先张法构件取；后张法构件取，此处，和分别为换算截面惯性矩和净截面惯性矩；——构件受拉区、受压区预应力钢筋截面重心至截面重心的距离；——构件受拉区、受压区纵向普通钢筋截面重心至构件截面重心的距离；——构件受拉区、受压区预应力钢筋和普通钢筋截面重心至构件截面重心轴的距离；——预应力钢筋传力锚固龄期为，计算考虑的龄期为t时的混凝土收缩应变，其终极值可按《公路桥规》表6.2.7取用；——加载龄期为，计算考虑的龄期为时的徐变系数，其终极值可按《公路桥规》表6.2.7取用。 5.5主梁次内力计算5.5.1预应力产生的二次内力在使用阶段，由于预应力钢筋的应力松弛.混凝土的收缩和徐变，都将使得钢筋预应力值减小，因而在使用阶段必须考虑由于预应力引起的结构次内力，本桥次内力结果如下：表5.2次内力计算单元号节点号弯矩单元号节点号弯矩114477.626272726974.6122139554282835668.333128924.1292944130.144135835.9303053166.3555130144.5313161104.4866123035.1323267968.0377114750.5333374468.5188104490.3343478794.469993819.29353582003.27101082116.42363675667.97111169286.12373784199.17121257479.89383882580.69131345242.06393979746.95141434392.76404075409.41151523072.83414169214.77161611281.97424262612.431717-987.637434354978.211818-13701.3444446248.461919-20606454538401.832020-15848.1464630067.532121-22262.7474722423.52222-17775.7484814315.372323-7890.9349495755.70424241526.6835050-3275.66252510489.155151-12725.4262618981.015252-17843第6章主要控制截面应力及承载能力验算根据《公路桥规》的规定，要对控制截面进行强度验算，强度验算包括正截面强度验算和斜截面强度验算。 6.1强度验算原理预用力混凝土受弯构件验算原则基本上与普通钢筋混凝土构件相同：当预应力钢筋的含筋量配置适当时，受拉区混凝土开裂退出工作，预应力钢筋和非预应力钢筋分别达到各自的抗拉设计强度Ry和Rg；受压区混凝土应力达到抗压设计强度Ra，非预应力钢筋达到其抗压设计强度，并假定受压区的混凝土应力按矩形分布。但受压区布有预应力钢筋时，其应力却达不到抗压设计强度，这就是与普通钢筋混凝土构件的唯一区别。6.1.1承载能力极限状态验算正截面承载能力计算，按照《公路桥规》4.2.3条计算的本设计箱型截面上翼缘有效宽度为=17298mm,厚度为280mm。取19节点支点截面计算，首先按公式判断截面类型。代入数据计算得：(6-11)(6-12)因为，所以中性轴位于腹板内，混凝土受压区为T形。由水平力平衡条件，即得：(6-13)，计算结果表明，支点截面的抗弯承载力满足要求。通过GQJS报表输出截面强度验算如下：表6.1强度验算单元节点NVM最大抗弯强度最小抗弯强度强度验算结论 22141953.498277.3101242.93223896.67-73105.65ok23141953.497022.1493190.73227525.76-74290.61ok33141953.497022.14114757.47227525.76-74290.61ok34141953.494239.82102794.43227625.55-74323.19ok44141953.494239.8281227.59233719.02-123410.73ok45141953.52032.1660683.73242651.17-128127.17ok55141953.52032.1660683.73245167.97-176749.98ok56141953.49-245.5739570.77257781.62-188063.41ok66141953.49-245.5739570.77229534.07-211449.57ok67141953.49-2590.3612062.66244028.86-224802.35ok77141953.49-2590.3612062.66213654.67-229624.82ok78141953.49-4987.86-13565.85229022.64-246141.5ok88141953.49-4987.86-13565.85192049.7-309607.4ok89141953.49-7438.77-41499.32206120.38-332291.03ok99141953.49-7438.77-41499.32164947.86-398873.92ok910141953.49-9958.86-76741.61177317.91-428786.95ok1010141953.49-9958.86-76741.61142789.88-489795.6ok1011141953.49-12614.69-120076.4151808.58-538468.06ok1111141953.49-12614.69-120076.4103110.08-596784.01ok1112141953.49-15062.24-164834.6105155.82-638278.7ok1212141953.49-15062.24-164834.652814.92-707391.58ok1213141953.49-17689.06-212473.756507.22-772811.93ok1313141953.49-17689.06-212473.70-838730.53ok1314141953.49-20979.89-258929.40-911200.53ok1414141953.49-20979.89-258929.40-970805.56ok1415141953.49-23466.32-3121640-1052696.9ok1515141953.49-23466.32-3121640-1113572.63ok1516141953.49-26032.96-3703920-1207912.59ok1616141953.49-26032.96-3703920-1270552.9ok1617141953.49-28557.28-431940.50-1378587.9ok1717141953.49-28557.28-431940.50-1092846.58ok1718141953.49-30946.57-499176.80-1210923.25ok1818141953.49-30946.57-499176.80-1226173.4ok1819141953.49-33631.88-571724.20-1553801.52ok1919141953.49-33631.88-571724.20-1553801.52ok1920141953.49-36806.38-661963.10-1678908.4ok2020141953.4955129.05-661963.10-1678662.56ok2021141953.4950819.03-573095.80-1553800.83ok2121141953.4950819.03-573095.80-1552577.36ok2122141953.4947120.63-502859.90-1224631.62ok2222141953.4947120.63-502859.90-1209525.67ok2223141953.4943807.91-439347.40-1091497.95ok 2323141953.4943807.91-439347.40-1076229.56ok2324141953.4940618.09-381830.80-972040.32ok2424141953.4940618.09-381830.80-952163.03ok2425141953.4937546.08-329982.70-1113572.63ok2525141953.4937546.08-329982.70-1052696.9ok2526141953.4934586.63-283467.50-970805.56ok2626141953.4934586.63-283467.50-911200.53ok2627141953.4930678.29-242447.50-838730.53ok2727141953.4931734.29-242447.50-776810.55ok2728141953.4927594.19-196559.90-702325.67ok2828141953.4928650.19-196559.90-646746.74ok2829141953.4924746.81-153752.60-587821.83ok2929141953.4924746.81-153752.648698.5-516977.6ok2930141953.4921687.01-96220.7547538.41-483321.76ok3030141953.4921687.01-96220.7592794.09-423447.85ok3031141953.518812.87-46923.1887891.8-391439.25ok3131141953.518812.87-46923.18122868.9-330132.6ok3132141953.516038.58-5299.14115209.86-309553.78ok3232141953.516038.58-5299.14151833.53-244774.05ok3233141953.513336.3629655.35142415.66-229591.3ok3333141953.513336.3629655.35176594.42-170814.96ok3334141953.510693.1263114.66166648.48-161194.53ok3434141953.510693.1263114.66164257.63-141228.38ok3435141953.58110.0391959.26155332.49-133554.56ok3535141953.58110.0391959.26154116.27-82818.04ok3536141953.54515.51106238.1148253.49-79667.53ok3636141953.54515.51105641.09142265.97-32711.62ok3637141953.51899.71105387.99142265.97-32711.62ok3737141953.51899.71105510.55148253.49-79667.53ok3738141953.5-1128.3388287.9154091.32-82804.63ok3838141953.5-1128.3388287.9155316.89-133541.15ok3839141953.5-3296.7160332.13162074.68-139351.48ok3939141953.5-3296.7160332.13166648.48-161194.53ok3940141953.5-5497.9929026.76176594.42-170814.96ok4040141953.5-5497.9929026.76142415.66-229591.3ok4041141953.49-7731.1-10654.86151833.53-244774.05ok4141141953.49-7731.1-10654.86115209.86-309553.78ok4142141953.49-10007.25-56670.06122831.48-330032.05ok4242141953.49-10007.25-56670.0687854.38-391427.67ok4243141953.49-12350.15-90286.9292794.09-423447.85ok4343141953.49-12350.15-90286.9247538.41-483321.76ok4344141953.49-14832.06-130512.248698.5-516977.6ok 4444141953.49-14832.06-130512.20-587821.83ok4445141953.49-16906.11-1722190-646746.74ok4545141953.49-16906.11-1722190-725989.56ok4546141953.49-19058.11-221452.80-812391.36ok4646141953.49-19058.11-221452.80-891834.07ok4647141953.49-21861.56-268359.60-978613.15ok4747141953.49-21861.56-268359.60-1046847.82ok4748141953.49-23946.71-320643.50-1149333.18ok4848141953.49-23946.71-320643.50-1207644.73ok4849141953.49-26117.6-377632.30-961707.99ok4949141953.49-26117.6-377632.30-972909.21ok4950141953.49-28378.19-440331.50-1076820.49ok5050141953.49-28378.19-440331.50-1125999.96ok5051141953.49-30732.28-508998.90-1222408.19ok5151141953.49-30732.28-508998.90-1296054.23ok5152141953.49-33417.58-581463.90-1800456.46ok5252141953.49-33417.58-581463.90-1800456.46ok5253141953.49-36592.08-670319.10-2029551.2ok6.1.2使用阶段正截面应力验算全预应力混凝土构件在使用阶段，构件处于全截面参加工作的弹性工作状态，截面应力可按材料力学公式计算。对后张法构件混凝土受压边缘的法向应力按下列公式计算：(6-1)(6-2)(6-3)式中——受拉区、受压区预应力钢筋的有效预应力；——受拉区、受压区预应力钢筋的截面面积；——受拉区、受压区普通钢筋的截面面积；——受拉区、受压区预应力钢筋合力点至换算截面重心轴的距离；——受拉区、受压区普通钢筋重心至净截面重心轴的距离； ——受拉区、受压区预应力钢筋在各自合力点处由混凝土收缩和徐变引起的预应力损失值；——预应力钢筋与普通钢筋的合力；——净截面面积；——一期恒载、二期恒载；——包括冲击系数影响的汽车荷载弯矩标准值、人群荷载弯矩标准值。斜截面应力验算是选取若干最不利截面，计算在荷载效应标准值作用下截面的主压应力，并控制其满足《桥规》（JTGD62）规定的限制条件。由预加力和荷载效应标准值产生的混凝土主压应力和主拉应力可按下列公式计算：(6-4)(6-5)(6-6)(6-7)(6-8)式中：——在预加力和荷载效应标准值作用下，计算主应力点的混凝土法向压应力；——由竖向预应力钢筋的预加力产生的混凝土竖向压应力；——由预应力弯起钢筋的预加力竖直分力和荷载效应标准值产生的计算主应力点处的混凝土剪应力。经计算得各控制截面的上下缘最大、最小法向应力及最大、最小主拉压应力结果列如下表：表6-2控制截面应力值　上缘正应力下缘正应力主应力节点最大应力最小应力最大应力最小应力最小主拉最大主压 1-13.2676-16.42618.67271.4566-0.7518.9524210.8463-11.0260.4297-8.5686-0.6715.846337.6233-4.6217-0.2147-10.8383-0.137.6233415.6641-6.3394-3.3035-39.5255-0.3815.6641512.8467-4.9175-0.1891-22.1005-0.2912.8467611.0033-4.9043-0.7149-19.6833-0.2111.003378.4141-6.7267-0.1203-16.5304-0.168.414188.0782-6.91250.6489-13.3104-0.318.078297.3364-7.18851.6141-10.0465-0.557.3364106.7163-7.38892.3673-7.2113-0.587.0451115.9402-7.18422.7787-4.9586-1.026.1654125.9784-6.79922.748-4.1149-0.956.359135.4214-6.11992.9959-2.7975-0.845.5409145.3771-5.87674.2987-1.0632-0.925.8609155.4152-5.55895.3480.4226-0.966.2111165.5242-5.21336.18811.6968-0.926.8227175.5792-4.94966.92882.804-1.017.4131186.1506-4.93948.44344.8312-1.068.4434192.1467-4.5285.54733.5106-1.055.5473201.7471-4.12884.83063.3164-1.034.8306212.2727-4.58895.63773.5414-0.735.6377224.524-6.71279.52085.652-0.909.5208234.1841-6.73029.0175.047-0.799.017243.7462-6.84968.47993.8306-0.938.4799253.105-6.89496.280.4856-0.856.4014262.721-7.1195.5081-1.0095-0.985.728272.2467-7.38954.669-2.6567-0.915.005282.2446-7.86643.6246-5.5517-1.024.8762291.8479-7.9893.4623-6.9884-0.984.5125301.7272-8.2243.1581-9.5377-0.934.8657311.5622-7.95222.5509-11.9836-1.034.4896321.2288-7.78882.1054-14.3854-1.034.056330.7379-7.46771.8615-16.8427-1.053.5417341.8753-5.8336-0.5515-21.565-1.032.969351.2577-6.0561-2.6532-25.6101-1.021.72363.4899-2.035-1.3673-10.8473-0.903.4899372.4053-5.2422-4.4248-28.1613-1.002.4053383.9023-4.8999-3.1279-24.6956-1.023.9023393.129-6.9581-0.7612-19.4991-0.983.1454403.7606-7.4677-0.6073-16.4328-0.983.9284414.2311-8.3194-0.2303-13.1292-0.914.534424.294-9.07390.5631-9.8067-1.024.8897 434.3878-9.63591.408-6.9382-0.765.178444.3142-9.61691.972-4.2005-0.984.735455.5907-8.5813.6694-1.3774-0.815.9118466.2418-7.13064.65380.94-1.056.2418477.4905-5.91325.52532.4158-1.067.4905488.7277-4.66266.21993.6331-1.058.72774910.801-3.23579.37093.0434-1.0310.8015012.0717-2.119810.12413.35-1.0212.07175113.2672-1.060810.60793.4717-0.9013.2672526.1517-2.63446.75582.774-1.006.7558《桥规》（JTGD62）规定混凝土的主压拉应力应符合下式规定：(6-9)(6-10)经核对控制截面应力符合规范要求。第7章变形计算与预拱度设置及锚下局部应力验算 预应力混凝土连续梁桥的变形由两部分组成：一部分是预加力作用所产生的变形，即反拱度；另一部分是荷载作用产生的变形即挠度。一般情况下，这两部分变形方向相反，可以利用预加力形成的反拱度来抵消由荷载所产生的挠度。7.1挠度计算7.1.1变形计算、验算及预拱度设置计算原理预应力混凝土连续梁桥的变形由两部分组成：一部分是预加力作用所产生的变形，即反拱度；另一部分是荷载作用产生的变形即挠度。一般情况下，这两部分变形方向相反，可以利用预加力形成的反拱度来抵消由荷载所产生的挠度。然而，有时会因对预应力产生的反拱度预估不足，造成过分的反拱，反而出现不利的情况。因而，设计中进行变形计算，以避免因变形过大而影响使用功能。（1）短期变形计算①预加力引起的变形预应力混凝土构件由预加力作用引起的变形，可以采用结构力学的方法计算。考虑预加力短期影响的公式如下：（7-1-1）式中：Mp——由永存预加力（永存预应力的合力）在任意截面X处的弯矩值。——跨中作用单位力时在任意截面X处的弯矩值。主梁的计算跨径L=110m，50号混凝土的弹性模量=3.45×10Mpa,由截面换算的结果可知，主梁在各控制截面的换算截面的惯性矩各不相同，计算时以1/4梁跨截面几何特性作为全梁的平均截面几何特性，计算公式，α跨中挠度系数，查表得，M跨中弯矩，L跨径，Eh混凝土弹性模量，查表得Eh=3.45×104MPa，I0截面换算惯性矩，计算结果如下（向下为正，向上为正）。②使用荷载下的变形在使用荷载作用下，预应力混凝土构件的变形，可采用下面的一般公式进行计算。（7-1-2）式中：l—为梁的计算跨径； â—挠度系数，弯具图形状和支承的约束条件有关；Mt—构件截面开裂弯矩；M—使用荷载作用下的弯矩；对于全预应力混凝土和部分预应力混凝土A类构件；M＜Mf；对于部分预应力混凝土B类构件：M>Mt；Io—构件全截面的换算截面惯性矩；Io1—构件截面开裂后的换算截面惯性矩；（2）长期变形计算由于预应力、构件自重及二期恒载是持续作用的，而已求出使用荷载下变形只是由这些荷载引起的初始短期弹性变形，在长期持续荷载作用下，混凝土徐变将使变形增大。考虑混凝土徐变对预加力、自重及二期恒载变形影响后，长期变形的计算应用下列公式：（7-1-3）式中：——以施工预应力和构件自重作用时刻为砼加载龄期的徐变系数；——以二期恒载作用时刻为砼加载龄期的徐变系数。在上式中考虑预加力和结构自重同时起作用，即预应力施加后构件已拱起、脱模，长期最终变形可取t=的徐变系数计算求得。本设计中==2.27.1.2变形计算结果以跨中截面为例计算主梁的短期变形，长期变形的计算略。（1）边跨变形验算边跨跨中(12号单元)汽车荷载作用产生的挠度为：其中换算截面的惯性矩为I0=79.07561012mm＝5×1780×106×1100002/（48×0.95×3.5×104×19762×109）＝3.33mm（↓）<6000/600=100mm（满足要求）（2）中跨变形验算中跨跨中（36号单元）汽车荷载作用挠度：其中换算截面的惯性矩为I0=27.43131012mm＝5×1760×106×1100002/（48×0.95×3.45×104×13563×1012）＝7.26mm（↓）<110000/600=183mm（满足要求） 7.2变形验算及预拱度设置（1）边孔变形验算及预拱度设置①变形验算由上面可知汽车荷载作用下最大挠度为0.333cm，发生在跨中，而挠度限值为：L/600=6000/600=10cm即有=0.333cm〈10cm（2）中孔变形验算及预拱度设置①变形验算由上可知汽车荷载作用下最大挠度为0.726cm，发生在跨中，而挠度限值为：L/600=110000/600=18.3cm即有=0.726cm〈18.3cm②预拱度设置因在恒载及预应力引起主梁变形计算中已计入徐变影响，则采用L/4截面处的永存预加力矩作为全桥平均预加力计算值，即在使用阶段的预加力矩为：1129.4×38800×350=15337.3kNm则主梁反拱度（跨中截面）计算为=-=-5×15337.3×106×1100002/（48×0.95×3.45×104×13563×109）=-60.05㎜（↑）（3）由主梁自重和二期恒载作用引起的挠度=5×1100002×（6350+16700）×106/（48×0.95×3.45×104×13563×109）=79.66mm（↓）（4）使用荷载作用下跨中变形 =79.66-60.05+7.26=26.87mm（↓）