30米预应力砼T梁梁桥设计

摘要本设计是钢筋混凝土T型梁桥，我国的桥梁结构中多数都是使用T型桥梁。因为这种设计有它的很多的优点，它能够大大的实现资源的优化配置，能有效的发挥材料的性能，充分利用材料的作用；它能大大的降低成本，机械化操纵，节省工期；有利于就地取材。桥梁美观好看，坚实耐用。我国如今利用最为遍及的还是钢筋混凝土简支梁桥。这类设计方案在我国中、小型桥梁设计中普遍存在。因为这种设计有它的很多的优点，它能够大大的实现资源的优化配置，能有效的发挥材料的性能，充分利用材料的作用；机械化操纵，收缩工程工期，提高效率；所以在公路中，小跨径钢筋混凝土简支梁桥有比较大的优势和广阔长远的应用前景。在老师精心的指导下，在同学的帮助下，经过反复的计算演练和现场学习下，更是通过自己不断的学习，查阅了专业规范书籍，我在多方面都有所提高。通过这次设计认识到学生在课堂上的理论知识如果不能运用到实际当中去，那都成为一纸空谈，全面运用了学生所学专业知识，再通过实践达到结合的理论和实践帮助学生提高独立履行任务能力的效果,并帮助学生提高综合能力。关键词:简支梁桥；标准跨径；桥梁设计；造型设计；2AbstractIsthedesignofreinforcedconcreteTbeambridge,thebridgestructurearemostlyusedinTbridge.Becausethiskindofdesignhasitsmanyadvantages,itcangreatlytoachievetheoptimalallocationofresources,caneffectivelyplaytheperformanceofthematerial,makefulluseoftheroleofmaterial;Itcangreatlyreducethecost,mechanicalmanipulation,savethetimelimitforaproject;Forlocalmaterials.Thebridgeisbeautifulbeautiful,solidanddurable.Thisdesignundertheguidanceoftheteachercarefully,withthehelpoftheclassmates,afterrepeatedcalculationexercisesandfieldstudy,butalsothroughtheircontinuouslearning,consulttheprofessionalnormsbooks,Ihaveimprovedinmanyaspects.Throughthisdesignrealizethetheoreticalknowledgeofstudentsintheclassifyoucan'tapplyintopractice,itallbecomesapaperemptytalk,fulluseoftheirstudentslearnprofessionalknowledge,withsolidagainPracticetocombinethetheoryandpracticetohelpstudentsimprovetheeffectivenessoffulfillingtasksindependently,andhelpstudentstoimprovethecomprehensiveability.Keywords:simplysupportedgirderbridge;Standardmodels;Bridgedesign.Modelingdesign;3目录摘要···································1Abstract···································2目录···································3前言···································3第一章桥梁方案比较选择···························11.1桥梁方案比选原则···························11.2桥型特点·······························2第二章桥梁设计基本资料···························42.1地质条件·······························42.1.1地质层资料···························42.2工程地质评价·····························4第三章上部结构·······························63.1主要设计材料参数···························63.2横截面布置······························63.2.1主梁间距和主梁片数·······················62.2.2主梁跨中截面尺寸拟订······················7第三章主梁作用效应计算···························113.1永久作用效应计算···························113.1.1永久作用集度··························113.2可变作用效应计算···························143.2.1冲击系数和车道折减系数·····················143.2.2计算主梁的荷载横向分布系数···················143.2.3车道荷载的取值·························183.2.4计算可变作用效应························193.3主梁作用效应组合···························23第四章预应力钢束的估算及其布置·······················244.1跨中截面钢束的估算和确定·······················244.1.1按正常使用极限状态的应力要求估算钢束数·············244.1.2按承载能力极限状态估算钢束数··················244.2预应力钢束布置····························254.2.1跨中截面及锚固端截面的钢束位置·················254.2.2钢束起弯角和线形的确定·····················274.2.3钢束计算····························28第五章计算主梁截面几何特性·························315.1截面面积及惯性矩计算·························315.1.1净截面几何特性计算·······················3145.2截面静距计算·····························345.3截面几何特性汇总···························35第六章钢束预应力损失计算··························376.1预应力钢束与管道壁之间的摩擦引起的预应力损失·············376.2由锚具变形、钢束回缩引起的预应力损失·················386.3混凝土弹性压缩引起的预应力损失····················396.4由钢束应力松弛引起的预应力损失····················416.5混凝土收缩和徐变引起的预应力损失···················41第七章主梁截面承载力与应力验算·······················467.1持久状况承载能力极限状态承载力验算··················467.1.1正截面承载力验算························467.1.2斜截面承载力验算························497.2持久状况正常使用极限状态抗裂验算···················527.2.1正截面抗裂验算·························537.2.2斜截面抗裂验算·························547.3持久状态构件的应力验算························577.3.1.正截面混凝土压应力验算·····················577.3.2.预应力筋拉应力验算·······················597.3.3.截面混凝土主压应力验算·····················607.4短暂状况构件的应力验算························637.4.1预加应力阶段的应力验算·····················637.4.2.吊装应力验算··························64第八章主梁变形验算·····················错误!未定义书签。8.1计算由预加力引起的跨中反拱度·············错误!未定义书签。8.2计算由荷载引起的跨中挠度···············错误!未定义书签。8.3结构刚度验算·····················错误!未定义书签。8.4预拱度的设置·····················错误!未定义书签。参考文献···························错误!未定义书签。致谢···························错误!未定义书签。1第一章桥梁方案比较选择1.1桥梁方案比选原则1、安全是桥梁结构设计的前提随着改革开放力度的不断加大和城市车辆的飞速发展，城市交通运输工作十分繁忙，行车速度也在不断提高，桥梁结构不仅要考虑结构自身的受力安全，还要考虑桥梁构造的安全。2、经济是桥梁结构设计的保证一座桥梁建筑设计的再漂亮，如果它的造价比看上去的一般桥梁高出很多，那这座漂亮的桥梁设计也是失败的。要充分运用当地资源，最好就是可以就地取材，比如当地的砂和石料等。所以在桥梁设计中，在满足结构安全的前提下，应尽量地考虑经济原则。3、功能在桥梁结构设计中也不应忽视城市桥梁是不同于公路桥梁的，在城市交通日益拥挤的情况下，交通组织功能也放在重要位置，特别是城市立交，不仅桥上有车，桥下车辆也生生不息。如果不考虑交通功能，车辆撞击桥墩，造成桥梁坍塌等，这种事件在国内外时有发生。作为一个桥梁设计师必须意识到这一点，以此确定方案比选和桥梁分跨。4、美观是桥梁设计必须考虑的一部分城市桥梁建筑不仅是交通工程中的一个关键建筑，而且它作为美化环境的点缀物，所以设计必须仔细计划选择，精心设计和施工，不增加投资的情况下，使桥梁的美观效果。例如，在城市建立一座二三十米一跨的立交，无论用钢还是预应力砼，通常都有一根横梁，但由于人们视觉产生的错觉，所以经常作为曲梁下垂的梁挠度，看起来很不舒服，甚至害怕它掉的危险。事实上，一个拱弦曲梁，这是一个最简单的支持，这是集成在梁上，变得看不见，但它可以在桥的美化作用。综合考虑以上四项标准来进行桥梁的方案比选，最后的设计、施工将会变得容易，建成后的桥梁才是安全美、经济美、功能美与环境、视角美。21.2桥型特点1.1.1.第一方案：装配式预应力混凝土简支箱梁桥孔径布置：30m+60m+30m，全长120米,宽14.5m。由于为简支箱梁桥，每跨之间还留有5厘米的伸缩缝，桥面设有2.0％的横坡。（1）主梁结构构造：全桥采用等截面箱梁组合梁。桥面设有2％的横坡，0.0%的纵坡。（2）下部构造：采用三圆柱式桥墩；钻孔灌注桩式桩基础，桥台采用埋置式轻型桥台。（3）施工方案：全桥采用装配式施工方法。（4）装配式简支箱梁桥的特性：简支箱梁以其优良的力学性