预应力混凝土连续梁桥施工设计毕业论文

'预应力混凝土连续梁桥施工设计毕业论文目录第一章概述·····························41.1地质条件···························41.2主要技术指标·························41.3设计规范及标准························4第二章方案比选······························52.1概述·····························52.2比选原则···························52.3比选方案···························52.3.1预应力混凝土连续梁桥··················52.3.2预应力混凝土连续刚桥桥·················72.3.3普通上承式拱桥·····················82.4方案比较···························9第三章预应力混凝土连续梁桥总体布置·················123.1桥型布置···························123.2桥孔布置···························123.3桥梁上部结构尺寸拟定·····················123.4桥梁下部结构尺寸拟定·····················133.5本桥使用材料·························143.6毛界面几何特性计算······················14第四章荷载内力计算·························164.1模型简介···························164.2全桥结构单元的划分······················164.2.1划分单元原则······················164.2.2桥梁具体单元划分····················1792 4.3全桥施工节段的划分······················174.3.1桥梁划分施工分段原则··················174.3.2施工分段划分······················174.4恒载、活载内力计算······················174.4.1恒载内力计算······················174.4.2悬臂浇筑阶段内力····················184.4.3边跨合龙阶段内力····················194.4.4中跨合龙阶段内力····················204.4.5活载内力计算······················214.5其他因素引起的内力计算····················234.5.1温度引起的内力计算···················234.5.2支座沉降引起的内力计算·················254.5.3收缩、徐变引起的内力计算················264.6内力组合···························284.6.1正常使用极限状态的内力组合···············284.6.2承载能力极限状态的内力组合···············29第五章预应力钢束的估算与布置····················325.1钢束估算···························325.1.1按承载能力极限计算时满足正截面强度要求·········325.1.2按正常使用极限状态的应力要求计算············335.2预应力钢束布置························395.3预应力损失计算························405.3.1预应力与管道壁间摩擦引起的应力损失···········405.3.2锚具变形、钢筋回缩和接缝压缩引起的应力损失········415.3.3混凝土的弹性压缩引起的应力损失·············415.3.4钢筋松弛引起的应力损失·················425.3.5混凝土收缩徐变引起的应力损失··············425.3.6有效预应力计算·····················445.4预应力计算··························45第六章强度验算···························486.1正截面承载能力验算······················486.2斜截面承载能力验算······················51第七章应力验算···························557.1短暂状况预应力混凝土受弯构件应力验算·············557.1.1压应力验算·······················557.1.2拉应力验算·······················5592 7.2持久状况正常使用极限状态应力验算··············607.2.1持久状况(使用阶段)预应力混凝土受压区混凝土最大压应力验算607.2.2持久状况(使用阶段)混凝土的主压应力验算·········627.2.3持久状况(使用阶段)预应力钢筋拉应力验算·········65第八章抗裂验算···························688.1正截面抗裂验算························688.2斜截面抗裂验算························72致谢·································77参考文献································78附录：外文翻译····························7992 第一章概述1.1地质条件桥位地质地形图图1-1地质图1.2主要技术指标桥面净宽：11＋2×0.5m（分离式、无人行道）设计荷载：公路－Ｉ级行车速度：100km/h桥面横坡：2%通航要求：无温度：最高年平均温度43℃，最低年平均温度-5℃。1.3设计规范及标准1、《公路工程技术标准》（JTGB01-2003）。2、《公路桥涵设计通用规范》（JTGD60-2004）。3、《公路桥涵地基与基础设计规范》（JTGD63-2007）。4、《公路桥涵施工技术规范》（JTJ041-2000）。92 5、《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62-2004）。第二章方案比选2.1概述桥式方案比选是初步设计阶段的工作重点，一般要进行多个方案比较。各方案均要求提供桥式布置图，图上必须标明桥跨位置，高程布置，上、下部结构形式及工程数量。对推荐方案，还要提供上、下部结构的结构布置图，以及一些主要的及特殊部位的细节处理图。设计方案的评价和比较，要全面考虑各项指标，综合分析每一方案的优缺点，最后选定一个符合当前条件的最佳推荐方案。有时，占优势的方案还应吸取其他方案的优点进一步加以改善。2.2比选原则设计从安全性、技术适用性、施工难度、设计施工周期、经济性、实用性和观赏性等几方面对各比选方案进行评比，其中安全性为主要因素。2.3比选方案根据设计任务要求,依据现行公路桥梁设计规范,综合考虑桥位地质地形条件，拟定了三个比选方案：方案一：预应力混凝土连续梁桥方案二：预应力混凝土连续刚构桥方案三：普通上承式拱桥2.3.1预应力混凝土连续梁桥1.桥梁总体设计该桥为预应力混凝土连续梁桥，共三跨，为58m+100m+58m=216m。边跨与中跨比为58/100=0.58在0.5～0.8之内，主跨跨中处桥面高程为835.25m，桥面横坡为2%。92 图2-1连续梁桥布置图2.主梁a.截面形式：本桥箱梁为单箱单室截面，箱底宽6.5m，两侧翼缘宽2.75m，箱梁顶面全宽为12m。b.截面尺寸：箱梁在各墩支点处的截面高度为1/15L～1/20L，取1/16.7L即6m，在跨中及桥端支点处的截面高度为1/30L～1/50L，取1/36.4L即2.75m；箱梁顶板厚30cm（跨中）～48cm（支点），腹板厚50cm（跨中）～75cm（支点），底板厚30cm（跨中）～70cm（支点）。c.横隔板的设置：上部结构箱梁在各墩支点及桥端支点处设横隔板。墩支点处横隔板厚250cm，端支点处横隔板厚150cm，横隔板与箱梁连接处均设有承托。图2-2跨中与墩顶截面图3.基础桥墩基础连成整体，基础采用嵌岩型钻孔灌注桩群桩基础，桥墩为6m×6.5m的空心墩，材料为C40钢筋混凝土。4.施工方式主梁采用悬臂节段浇筑施工，桥墩采用爬模法施工，两端桥台采用整体现浇。2.3.2预应力混凝土连续刚构桥92 1.桥梁总体设计该桥为预应力混凝土连续刚构桥，共三跨，为58m+100m+58m=216m。边跨与中跨比为58/100=0.58在0.5～0.8之内，主跨跨中处桥面高程为835.25m，桥面横坡为2%。图2-3连续刚构桥布置图2.主梁a.截面形式：本桥箱梁为单箱单室截面，箱底宽6.5m，两侧翼缘宽2.75m，箱梁顶面全宽为12m。b.截面尺寸：箱梁在各墩支点处的截面高度为1/15L～1/20L，取1/16.7L即6m，在跨中及桥端支点处的截面高度为1/30L～1/50L，取1/36.4L即2.75m；箱梁顶板厚30cm（跨中）～48cm（支点），腹板厚50cm（跨中）～75cm（支点），底板厚30cm（跨中）～70cm（支点）。c.横隔板的设置：上部结构箱梁在各墩支点及桥端支点处设横隔板。墩支点处设两个厚300cm横隔板，端支点处横隔板厚150cm，横隔板与箱梁连接处均设有承托。图2-4跨中与墩顶截面图3.基础桥墩基础连成整体，基础采用嵌岩型钻孔灌注桩群桩基础，桥墩为3m×6.5m的双薄壁空心墩，材料为C40钢筋混凝土。4.施工方式主梁采用悬臂节段浇筑施工，桥墩采用爬模法施工，两端桥台采用整体现浇。92 2.3.3普通上承式拱桥1.桥梁总体设计该桥为普通上承式拱桥，主跨跨径为150m，拱高为25m，矢跨比为25/150=1/6，在1/5～1/10之内，主跨跨中处桥面高程为835.25m，桥面横坡为2%。图2-5普通上承式拱桥布置图2.主梁a.截面形式：本桥主梁为空心板截面，板高80cm，板宽120cm。b.截面尺寸：空心板截面高度为80cm，空心板顶、底板厚15cm，肋宽30cm。图2-6空心板截面图3.主拱圈a.截面形式：本桥主拱圈采用等截面悬链线，由6*1.6m的小箱梁组成，箱梁顶面全宽为9.6m。b.截面尺寸：主拱圈的截面高度为2.3m；箱梁顶、底板厚25cm，肋板厚15。c.横隔板的设置：主拱圈内部在拱脚以上10m段内加厚顶、底、侧板，以达最佳受力效果。92 图2-7主拱圈截面图4.拱上立柱拱上立柱为直径1m的空心墩。5.基础桥墩基础连成整体，基础采用嵌岩型钻孔灌注桩群桩基础，桥墩均为直径1m的空心墩，材料为C40钢筋混凝土。6.施工方式主梁采用预制节段拼装施工，桥墩采用爬模法施工。2.4方案比较方案比选从该桥桥址的实际地理位置地形环境，结合实用耐久、安全可靠、经济合理、美观和有利于环保的设计原则综合考虑。从安全、功能、经济、美观、施工、占地与工期多方面比选，最终确定桥梁形式。a.实用性桥上应保证车辆安全畅通，并应满足将来交通量增长的需要。桥下应满足泄洪、安全通航或通车等要求。建成的桥梁应保证使用年限，并便于检查和维修。只有满足了这一基本条件后，才能谈得上对桥梁结构的其他要求，既做到总造价经济，又保证工程质量和使用安全可靠。b.舒适与安全性现代桥梁设计越来越强调舒适度，故应控制桥梁的振幅，避免车辆受到过大振动与冲击。整个桥跨结构及各部件，在制造、运输、安装和使用过程中应具有足够的强度、刚度、稳定性和耐久性。c.经济性设计的经济性应综合发展远景及将来的养护和维修等费用。d.美观一座桥梁，尤其是作为一个城市或地区的标志性建筑的大跨径桥梁更应具有优美的外形，同时应与周围的景致相协调一致。合理优美的结构布局和轮廓是美观的主要因素，而非豪华的装饰。e.有利于环保桥梁设计应考虑环境保护和可持续发展的要求。从桥位选择、桥跨布置、基础方案、墩身外形、上部结构施工方法、施工组织设计等全面考虑环境要求，采取必要的工程控制措施，并建立环境监测保护体系，将不利影响减至最小。方案比选时应根据上述原则，对拟定的桥梁比选方案作出综合评估，选出最优的桥梁方案。以下为各比选方案的性能对比表：92 表2.1比选方案对照表比选方案比较项目预应力混凝土连续梁桥预应力混凝土连续刚构桥普通上承式混凝土拱桥跨径布置(m)58+100+5858+100+582*11+2+150+2+4*11桥面高程(m)835.25835.25835.25受力特点主要受弯拉以及与预应力产生的截面主压应力主要受弯拉以及与预应力产生的截面主压应力主要受压技术及施工适用性设计可靠成熟，技术先进、难度不大。施工机械化程度高，方法简便，无需大型设备，但施工线性与合拢技术要求较高。设计可靠成熟，技术先进、难度不大。施工机械化程度高，方法简便，无需大型设备，但施工线性与合拢技术要求较高。桥梁跨越能力大，抗风稳定性好，技术先进、无需大型设备，只需少量钢材，节省造价。安全性技术成熟，计算简单，施工方法简单，质量好，整体性好，刚度大，可保证工程本身安全，同时行车性能良好，可保证司机正常行车，满足交通运输安全要求。一般做成薄壁墩，墩的刚度小，难以承受船舶撞击，但此处不通航，对桥墩有利，因墩梁固结墩处可承受较大弯矩，梁身可做薄，基础沉降对结构影响大。承受的水平推力对基础要求较高，由变形引起的次内力对全桥受力非常不利。拱桥施工阶段是全桥刚度最弱的时候，施工时有一定风险。经济性施工技术成熟，方法简单，易掌握，需要的机具少，无需大型设备，可充分降低施工成本，需要大型支座，需较多预应力钢筋，基础施工复杂。无需支座，节省大型支座费用，其他与连续梁基本相同，养护费用小。施工技术成熟，方法简单，易掌握，需要的机具少，无需大型设备，可充分降低施工成本，所用材料普通，用钢量小，节省材料。92 实用性伸缩缝少，结构刚度大，变性小，动力性能好，主梁性能好，主梁变形挠曲线平缓，行车平顺，通畅，安全，可满足交通运输要求，且施工简单，但工期长。行车平顺，通畅，安全，可满足交通运输要求，施工技术成熟，易保证工程质量，桥下净空大，可满足通航要求，属有推力体系，对地基要求比连续梁高。行车性能好，视野开阔，结构刚度较大，抗风性能好，用钢量小，可以就地取材。美观性结构简洁，比例匀称，高墩大跨，线性优美，座落在该山谷再适合不过了。结构简洁，比例匀称，高墩细梁，如蜻蜓点水落在河上。但现代感不强，与悬索桥、斜拉桥相比，略逊风骚。主拱曲线本身孕育着强烈的美感，柔美的拱轴线与直线型的梁柱结合，具有刚强坚毅的态势。设计、施工周期设计施工难度低，进度较快、周期较短，大约10个月设计施工难度低，进度快、周期短，大约9个月设计施工较复杂，周期较长，工期大约需要12个月。通过对各设计方案在技术及施工适用性，安全性，经济性，实用性，美观性，设计、施工周期等几方面的综合对比分析，结合玉溪大桥总体布置的需要，预应力混凝土连续梁桥优势明显，被确定为最终设计方案。第三章预应力混凝土的连续梁桥总体布置3.1桥型布置本设计采用三跨预应力混凝土变截面连续梁结构，桥梁总长216m，桥梁起始里程桩号为K145+370.00m，终止里程桩号为K145+586.00m，桥面标高为835.25m。3.2桥孔布置92 连续梁跨径的布置可采用等跨和不等跨两种。采用等跨布置结构简单，模式统一，适于采用顶推法、移动模架法或简支转连续法施工的桥梁，但等跨布置将使边跨内力控制全桥设计，不是很经济。所以，连续梁跨径布置一般以采用不等跨形式。为减少等跨布置时边跨及中跨跨中正弯矩，可将连续梁设置成不等跨形式。从桥梁美学的角度看，连续梁桥跨数不多时，一般采用奇数孔，三跨及五跨较为常见。对三跨连续梁，边跨与中跨跨径之比一般为0.5～0.8。    本设计推荐方案根据任务书要求及桥址地形、地质条件等确定为58m+100m+58m的形式，边跨与中跨之比为0.58。图3-1连续梁总体布置图3.3桥梁上部结构尺寸拟定1.顺桥向梁的尺寸拟定a.墩顶处梁高：根据规范，梁高为1/16～1/20L，取L/16.7即6m。b.跨中梁高：根据规范，梁高为1/30～1/50L，取L/36.4即2.75m。c.梁底曲线：根据规范，选用1.8次曲线。2.横桥向的尺寸拟定箱梁跨中底板厚度一般按构造选定，若不配预应力筋，厚度可适当取值，当跨度较大，跨中正弯矩较大，需要配置一定数量的钢束或钢筋时，厚度应加厚。腹板的功能是承受截面的剪应力和主拉应力。在预应力梁中，因为弯束对外剪力的抵消作用，所以剪应力和主拉应力的值比较小，腹板不必设得太大；同时，腹板的最小厚度应考虑力筋的布置和混凝土浇筑要求，其设计经验为：腹板内无预应力筋时，采用三十公分92 ，腹板内有预应力筋管道时，应适当加厚；腹板内有锚头时，厚度应更大。根据任务书设计要求本推荐桥型方案横截面采用的是单箱单室的箱型截面。根据上述规范：顶板厚度取30cm；跨中处底板厚30cm，支点处底板厚为125cm,中间底板板厚成1.8次抛物线性变化；跨中处腹板厚度采用50cm，支点处腹板采用75cm图3-2连续梁跨中截面与墩顶截面3.桥面铺装和线型的选定桥面铺装：根据《桥梁工程》选用8cm防水混凝土铺装层和2cm厚的沥青混凝土磨耗层，共计10cm厚。桥面横坡：根据规范规定为1.5%～3.0%,取2%,该坡度由梁底支座控制。3.4桥梁下部结构尺寸拟定主墩采用薄壁空心墩，桥墩宽度为6m，顺桥向壁厚为0.9m,横桥向壁厚为1.2m，横桥向宽度取与梁底同宽6.5m，墩高分别为50m。根据给出的地质条件，认为地质条件较好，基础采用钻孔灌注桩基础。承台纵、横桥向宽均为9m，厚3.0m。4根桩的桩径2m，净间距3m。3.5本桥使用材料1.混凝土箱梁采用C55号，墩身和基础采用C40号，其他结构全部采用C25号砼。 2.钢材预应力钢材：纵、横向钢筋采用φ15.24㎜钢绞线,公称抗拉强度为fpk=1860MPa,张拉控制强度用0.75fpk=1375MPa,Ep=1.95×105MPa，设计中有19股、17股和12股，采用OVM15-15型锚具，单个锚具的回缩为6mm。竖向预应力筋采用精扎螺纹钢筋，采用扁锚。所有钢绞线均符合ASTM416-87A的技术标准。非预应力钢筋：直径≥12mm的用Ⅱ级螺纹钢筋，直径<12mm的用Ⅰ级光圆钢筋。带肋钢筋应符合《钢筋混凝土用热轧带肋钢筋》GB1499.2—2007的规定、光圆钢筋应符合《钢筋混凝土用热轧光圆钢筋》GB1499.1—2007的规定。92 3.预应力管道采用钢波纹圆、扁管成型；4.伸缩缝伸缩缝采用HXC-80A定型产品，全桥共2道。 5.桥梁支座单向活动和双向活动盆式支座。  6.梁设计荷载根据设计任务书规定：公路—Ⅰ级3.6毛界面几何特性计算毛界面几何特性计算通过madis有限元程序进行计算，其计算结果如下表：表3.1毛界面几何特性单元位置面积(mm^2)Iyy(mm^4)Izz(mm^4)Czp(mm)Czm(mm)WArea(mm^2)中和轴移动距离局部-y(mm)局部-z(mm)1I1.78E+071.43E+131.14E+141208.91541.11.76E+070.0-0.42I1.78E+071.43E+131.14E+141209.01541.01.76E+070.0-0.53I1.78E+071.43E+131.14E+141209.31540.71.76E+070.0-0.84I1.30E+071.23E+131.04E+141119.61630.41.27E+070.0-3.15I1.14E+071.13E+139.83E+131079.81670.21.11E+070.0-5.36I9.67E+069.92E+129.22E+131019.81730.29.33E+060.0-7.27I9.67E+069.92E+129.22E+131019.81730.29.33E+060.0-7.28I9.79E+061.01E+139.27E+131022.91727.19.32E+060.3-10.49I1.00E+071.13E+139.43E+131080.81781.89.51E+060.3-14.110I1.02E+071.26E+139.58E+131138.61843.09.71E+060.3-13.611I1.05E+071.42E+139.74E+131199.01907.89.92E+060.3-11.812I1.06E+071.58E+139.76E+131254.01984.01.01E+070.0-0.513I1.24E+072.01E+131.09E+141398.22065.81.19E+070.08.314I1.32E+072.56E+131.14E+141538.02232.01.27E+070.016.015I1.41E+073.24E+131.19E+141687.52405.51.35E+070.023.916I1.49E+074.01E+131.24E+141836.32575.01.44E+070.031.717I1.58E+074.94E+131.29E+141992.62751.51.52E+070.040.418I1.68E+076.05E+131.35E+142158.32933.11.61E+070.048.019I1.77E+077.36E+131.40E+142331.33121.71.70E+070.056.520I1.88E+079.33E+131.47E+142590.83350.21.81E+070.067.892 21I2.72E+071.22E+141.75E+142756.03244.02.65E+070.050.522I2.72E+071.22E+141.75E+142755.93244.12.65E+070.050.623I2.72E+071.22E+141.75E+142756.03244.02.65E+070.050.524I1.88E+079.33E+131.47E+142590.83350.21.81E+070.067.825I1.77E+077.37E+131.40E+142332.63120.41.70E+070.055.226I1.67E+076.07E+131.35E+142161.92929.51.61E+070.044.427I1.58E+074.96E+131.29E+141998.22745.91.52E+070.034.728I1.49E+074.04E+131.24E+141843.02568.31.44E+070.025.029I1.41E+073.26E+131.19E+141695.42397.71.35E+070.016.130I1.32E+072.58E+131.14E+141547.02223.01.27E+070.07.031I1.24E+072.03E+131.09E+141408.12055.91.19E+070.0-1.532I1.06E+071.60E+139.72E+131266.01972.01.01E+070.0-12.633I1.04E+071.43E+139.55E+131208.51898.39.92E+060.0-21.334I1.02E+071.28E+139.40E+131154.11827.59.71E+060.0-29.235I9.93E+061.15E+139.26E+131103.01759.69.51E+060.0-36.236I9.81E+061.03E+139.26E+131049.61700.49.33E+060.0-37.137I9.81E+061.03E+139.26E+131049.71700.39.33E+060.0-37.138I9.81E+061.03E+139.26E+131049.71700.39.33E+060.0-37.1第四章内力计算及荷载组合4.1模型简介上部结构采用MIDAS桥梁软件进行成桥和各施工阶段状态下恒载、活载、预应力、混凝土收缩、徐变、支座强迫位移、温度变化、等作用的计算。横向按框架和简支板考虑固端影响的模式进行计算，按其最不利内力控制截面设计。主桥合扰在夜间温度较低时进行，合扰顺序为先边跨再中跨。下部结构按最不利荷载组合进行设计，支座沉降按1cm考虑。4.2全桥结构单元的划分4.2.1划分单元原则92 全桥按平面杆系结构进行分析，考虑梁的跨径、截面变化、施工方法、预应力布置等因素，按照杆系程序分析原理，遵循结构离散化的原则，在适当位置划分节点：1.杆件的起点和终点及边界支承处；2.杆件的转折点和截面的变化点；3.施工分界线处和预应力锚固点；4.单元长度过大时，应适当细分；5.需验算的截面处；6.位移不连续，需进行主从约束时。图4-1结构离散模拟图4.2.2桥梁具体单元划分桥梁总长216米，共分为76个单元，每一个施工阶段自成一个单元，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，这样便于模拟施工过程，而且这些截面正是需要验算的截面。4.3全桥施工节段划分4.3.1桥梁划分施工分段原则1.有利于结构的整体性，尽量利用伸缩缝或沉降缝、在平面上有变化处以及留茬而不影响质量处。2.分段应尽量使各段工程量大致相等，以便于施工组织节奏流畅，使施工均衡。3.施工段数应与主要施工过程相协调，以主导施工为主形成工艺组合。工艺组合数应等于或小于施工段数。4.分段的大小要与劳动组织相适当，有足够的工作面。4.3.2施工分段划分全桥整体采用悬臂节段浇筑施工法，两端桥台附近单元使用整体支架现浇法。19～24单元与53～5892 单元为0号块，以后每向外悬出一块即为一个施工阶段，分别为1～11号块，两端的1～5和72～76单元为边跨整体现浇段，单元6、7和70、71为边跨合拢节段，36～41单元为中跨合拢节段4.4恒载、活载内力计算4.4.1恒载内力计算恒载内力主要为一期恒载的内力和二期恒载的内力叠加，其弯矩、剪力及轴力如图所示：图4-2成桥阶段弯矩图图4-3成桥阶段剪力图92 图4-4成桥阶段轴力图4.4.2悬臂浇筑阶段内力浇筑0号块，拼装挂蓝，悬臂浇注各箱梁梁段并张拉相应顶板纵向预应力束，悬臂浇注结束时全桥的恒载内力:图4-5最大悬臂阶段弯矩图图4-6最大悬臂阶段剪力图92 图4-7最大悬臂阶段轴力图4.4.3边跨合龙阶段内力安装排架并按施工要求进行预压，现浇边跨等高粱段，达到强度要求后，浇注边跨合龙段，张拉边跨底板纵向预应力束。此时全桥恒载内力：图4-8边跨合拢阶段弯矩图图4-9边跨合拢阶段剪力图92 图4-10边跨合拢阶段轴力图4.4.4中跨合龙阶段内力拼装中跨合龙吊架，焊接合龙段骨架，绑扎合龙段钢筋，浇注中跨合龙段，张拉中跨底板纵向预应力束。中跨合龙完成后的全桥恒载内力：图4-11中跨合拢阶段弯矩图图4-12中跨合拢阶段剪力图92 图4-13中跨合拢阶段轴力图4.4.5活载内力计算1.影响线的计算将单位荷载P=1作用在各桥面的节点上，求得结构的变形及内力，可得位移影响线和内力影响线。2.活载因子的计算1）冲击系数桥梁结构的基频反映了结构的尺寸、类型、建筑材料等动力特性内容，它直接反映了冲击系数与桥梁结构之间的关系。不管桥梁的建筑材料、结构类型是否有差别，也不管结构尺寸与跨径是否有差别，只要桥梁结构的基频相同，在同样条件的汽车荷载下，就能得到基本相同的冲击系数。桥梁的自振频率（基频）宜采用有限元方法计算，对于连续梁结构，当无更精确方法计算时，也可采用下列公式估算：式中：l—结构的计算跨径（m）；E—结构材料的弹性模量（N/m^2）；Ic—结构跨中截面的截面惯矩（m^4）；mc—结构跨中处的单位长度质量（kg/m），当换算为重力计算时，其单位应为（Ns^2/m^2）；G—结构跨中处延米结构重力（N/m）；g—重力加速度，g=9.81(m/s^2)计算连续梁的冲击力引起的正弯矩效应和剪力效应时，采用92 ；计算连续梁的冲击力引起的负弯矩效应时，采用。μ值可按下式计算：当ƒ＜1.5Hz时，μ=0.05当1.5Hz≤ƒ≤14Hz时，μ=0.1767lnƒ‐0.0157当ƒ＞14Hz时，μ=0.452）车道折减系数Msdis程序在加载车道之后会自动考虑3.车道荷载汽车荷载是由车道荷载和车辆荷载组成的。车道荷载由均布荷载和集中荷载组成。公路—I级车道荷载的均布荷载标准值为qk=10.5KN/m,集中荷载标准值为Pk=360KN。车道荷载的均布荷载应满布于使结构产生最不利效应的同号影响线上，集中荷载标准值只作用于相应影响线中最大影响线峰值处。验算荷载的影响间接反映在汽车荷载中。图4-14车道荷载弯矩包络图图4-15车道荷载剪力包络图92 图4-16车道荷载轴力包络图4.5其他因素引起的内力计算4.5.1温度引起的内力计算图4-17整体升温效应弯矩图图4-18整体升温效应剪力图92 图4-19整体升温效应轴力图图4-20整体降温效应弯矩图图4-21整体降温效应剪力图92 图4-22整体降温效应轴力图4.5.2支座沉降引起的内力计算图4-23支座沉降效应弯矩包络图图4-24支座沉降效应剪力包络图92 图4-25支座沉降效应轴力包络图4.5.3收缩、徐变引起的内力计算图4-26收缩效应弯矩图图4-27收缩效应剪力图92 图4-28收缩效应轴力图图4-29徐变效应弯矩图图4-30徐变效应剪力图92 图4-31徐变效应轴力图4.6内力组合根据我国现行公路桥涵设计规范，应进行正常使用极限状态的内力组合和承载能力极限状态的内力组合。4.6.1正常使用极限状态的内力组合组合I作用短期效应组合:组合II作用长期效应组合:式中:Ssd—作用短期效应组合设计值；SGik—第i个永久作用效应的标准值；ψ1j—第j个可变作用效应的频率值系数，汽车荷载（不计冲击力）ψ1=0.7，人群荷载ψ1=1.0，风荷载ψ1=0.75，温度梯度作用ψ1=0.8，其他作用ψ1=1.0；ψ1jSQjk—第j个可变作用效应的频率值。SQik—汽车荷载效应（含汽车冲击力、离心力）的标准值；Sld—作用长期效应组合设计值；Ψ2j—第j个可变作用效应的频率值系数，汽车荷载（不计冲击力）ψ2=0.4，人群荷载ψ2=1.0，风荷载ψ2=0.75，温度梯度作用ψ2=0.8，其他作用ψ2=1.0；ψ2jSQjk—第j个可变作用效应的频率值。4.6.2承载能力极限状态的内力组合92 组合Ⅲ基本组合:或式中:Sud—承载能力极限状态下作用基本组合的效应组合设计值；γ0—结构重要性系数，按《公路桥涵设计通用规范》JTGD60—2004表1.0.9规定的结构设计安全等级采用，对应于设计安全等级一级、二级和三级分别取1.1、1.0和0.9；γGi—第i个永久作用效应的分项系数，应按《公路桥涵设计通用规范》JTGD60—2004表4.1.6的规定采用；SGik—第i个永久作用效应的标准值；SGid—第i个永久作用效应的设计值；γQ1—汽车荷载效应（含汽车冲击力、离心力）的分项系数，取γQ1=1.4。当某个可变作用在效应组合中其值超过汽车荷载效应时，则该作用取代汽车荷载，其分项系数应采用汽车荷载的分项系数；对专为承受某作用而设置的结构或装置，设计时该作用的分项系数取与汽车荷载同值；计算人行道板和人行道栏杆的局部荷载，其分项系数也与汽车荷载取同值；SQik—汽车荷载效应（含汽车冲击力、离心力）的标准值；SQid—汽车荷载效应（含汽车冲击力、离心力）的设计值；γQj—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，取γQj=1.4，但风荷载的分项系数取γQj=1.1；SQjk—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；SQjd—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个可变作用效应的设计值；ΨC—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（或其他一种可变作用）组合时，人群荷载（或其他一种可变作用）的组合系数取ψc=0.80；当除汽车荷载效应（含汽车冲击力、离心力）外尚有两种其他可变作用参与组合时，其组合系数取ψc=0.70；尚有三种可变作用参与组合时，其组合系数取ψc=0.60；尚有四种及多于四种的可变作用参与组合时，取ψc=0.50。主要荷载组合92 根据结构各部分对强度、刚度、稳定性的验算需要,设计中考虑的主要荷载组合见表4.1。表4.1荷载组合表荷载组合类型说明1承载能力1.2恒荷载+1.0徐变+1.0收缩+1.4活载+0.98人群+0.98升温+0.98温度梯度2承载能力1.2恒荷载+1.0徐变+1.0收缩+1.4活载+0.98人群+0.98降温+0.98温度梯度3承载能力1.0恒荷载+1.0徐变+1.0收缩+1.4活载+0.98人群+0.98升温+0.98温度梯度4承载能力1.0恒荷载+1.0徐变+1.0收缩+1.4活载+0.98人群+0.98降温+0.98温度梯度5使用性能1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+0.667活载+0.7人群+1.0升温+0.8温度梯度6使用性能1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+0.667活载+0.7人群+1.0降温+0.8温度梯度7使用性能1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+0.381活载+0.4人群+1.0升温+0.8温度梯度8使用性能1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+0.381活载+0.4人群+1.0降温+0.8温度梯度9弹性阶段1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+1.0活载+1.0升温+1.0温度梯度10弹性阶段1.0恒荷载+1.0钢束一次+1.0徐变+1.0收缩+1.0活载+1.0降温+1.0温度梯度11包络承载能力包络12包络使用性能包络13包络弹性阶段包络92 第五章预应力钢束的估算与布置5.1钢束面积估算根据《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62-2004）规定，预应力梁应满足弹性阶段（即使用阶段）的应力要求和塑性阶段（即承载能力极限状态）的正截面强度要求。5.1.1.按承载能力极限计算时满足正截面强度要求预应力梁到达受弯的极限状态时，受压区混凝土应力达到混凝土抗压设计强度，受拉区钢筋达到抗拉设计强度。截面的安全性是通过截面抗弯安全系数来保证的。1）对于仅承受一个方向的弯矩的单筋截面梁，所需预应力筋数量按下式计算：如图：92 h0xNdfcd图5-1，（5-1），（5-2）解上两式得：受压区高度（5-3）预应力筋数（5-4a）或（5-4b）式中：—截面上组合力矩。—混凝土抗压设计强度；—预应力筋抗拉设计强度；—单根预应力筋束截面积；b—截面宽度2）若截面承受双向弯矩时，需配双筋的，可据截面上正、负弯矩按上述方法分别计算上、下缘所需预应力筋数量。这实际上忽略了双筋影响的存在（受拉区和受压区都有预应力筋）会使计算结果偏大，作为力筋数量的估算是允许的。5.1.2.按正常使用极限状态下的应力要求（主要依据）e上Np下Np上e下Y上Y下MminnMmax+++----Np下Np上Mmax合成+--Mmin合成92 图5-2规范《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62-2004）规定，截面上的预压应力应大于荷载引起的拉应力，预压应力与荷载引起的压应力之和应小于混凝土的允许压应力（为），或为在任意阶段，全截面承压，截面上不出现拉应力，同时截面上最大压应力小于允许压应力。写成计算式为：对于截面上缘（5-5）（5-6）对于截面下缘（5-7）（5-8）式中：—由预应力产生的应力，W—截面抗弯模量，—混凝土轴心抗压标准强度。Mmax、Mmin项的符号当为正弯矩时取正值，当为负弯矩时取负值，且按代数值取大小。一般情况下，由于梁截面较高，受压区面积较大，上缘和下缘的压应力不是控制因素，为简便计算，可只考虑上缘和下缘的拉应力的这个限制条件(求得预应力筋束数的最小值)。公式（5-5）变为（5-9）公式（5-7）变为（5-10）由预应力钢束产生的截面上缘应力和截面下缘应力分为三种情况讨论：1）截面上下缘均配有力筋和以抵抗正负弯矩，由力筋在截面上下缘产生的压应力分别为：92 （5-11）（5-12）将式（5-9）、（5-10）分别代入式（5-11）、（5-12），解联立方程后得到:（5-13）（5-14）令代入式（5-13）、（5-14）中得到：（5-15）（5-16）式中：Ap—每束预应力筋的面积；—预应力筋的永存应力(可取0.5～0.75估算)；e—预应力力筋重心离开截面重心的距离；K—截面的核心距；A—混凝土截面面积，取有效截面计算。2）当截面只在下缘布置力筋以抵抗正弯矩时当由上缘不出现拉应力控制时：（5-17）当由下缘不出现拉应力控制时：（5-18）92 3）当截面中只在上缘布置力筋以抵抗负弯矩时：当由上缘不出现拉应力控制时：（5-19）当由下缘不出现拉应力控制时：（5-20）当按上缘和下缘的压应力的限制条件计算时(求得预应力筋束数的最大值)。可由前面的式（5-6）和式（5-8）推导得：（5-21）（5-22）有时需调整束数，当截面承受负弯矩时，如果截面下部多配根束，则上部束也要相应增配根，才能使上缘不出现拉应力，同理，当截面承受正弯矩时，如果截面上部多配根束，则下部束也要相应增配根。其关系为：当承受时，当承受时，表5.1预应力钢束估算表单元位置顶/底Mg1(N*mm)Msum(N*mm)Mj(N*mm)ey(mm)Ny(N)Ay(mm^2)1I[1]底2.49E+052.00E-042.00E-04-8.56E+020.00E+000.01I[1]顶-1.78E+08-1.00E-04-1.00E-045.85E+020.00E+000.02I[2]底0.00E+001.02E+001.72E+00-9.26E+021.00E-030.02I[2]顶-1.80E+08-3.58E+08-5.01E+086.59E+023.04E+05241.03I[3]底2.61E+091.85E+092.43E+09-1.11E+031.47E+061169.83I[3]顶-1.99E+08-1.04E+09-1.24E+098.58E+027.53E+05597.492 4I[4]底3.64E+092.67E+093.50E+09-1.27E+032.12E+061683.14I[4]顶-8.98E+07-1.37E+09-1.61E+098.38E+029.79E+05776.75I[5]底7.50E+096.50E+098.48E+09-1.47E+035.14E+064078.25I[5]顶-1.47E+08-3.51E+09-4.13E+098.80E+022.51E+061988.26I[6]底9.48E+099.90E+091.29E+10-1.58E+037.80E+066188.36I[6]顶-3.64E+09-5.65E+09-6.65E+098.20E+024.03E+063199.67I[7]底9.80E+091.11E+101.45E+10-1.58E+038.76E+066953.47I[7]顶-2.57E+09-6.51E+09-7.66E+098.20E+024.64E+063684.28I[8]底9.87E+091.23E+101.60E+10-1.57E+039.67E+067673.98I[8]顶-1.73E+09-7.36E+09-8.67E+097.20E+025.25E+064168.89I[9]底7.57E+091.64E+102.10E+10-1.15E+031.22E+079721.69I[9]顶-1.18E+09-1.08E+10-1.27E+108.81E+027.39E+065866.810I[10]底1.09E+091.94E+102.47E+10-1.21E+031.38E+0710968.710I[10]顶-9.00E+09-1.42E+10-1.67E+109.14E+029.35E+067420.511I[11]底1.00E-042.16E+102.71E+10-1.30E+031.45E+0711533.311I[11]顶-2.09E+10-1.76E+10-2.08E+109.74E+021.11E+078837.312I[12]底0.00E+002.28E+102.82E+10-1.40E+031.45E+0711526.212I[12]顶-3.59E+10-2.11E+10-2.48E+101.02E+031.28E+0710125.313I[13]底0.00E+002.32E+102.82E+10-1.36E+031.36E+0710767.413I[13]顶-5.51E+10-2.45E+10-2.88E+101.13E+031.39E+0711003.514I[14]底0.00E+002.29E+102.71E+10-1.38E+031.27E+0710089.314I[14]顶-7.89E+10-2.79E+10-3.28E+101.24E+031.45E+0711524.215I[15]底0.00E+002.18E+102.50E+10-1.40E+031.15E+079117.715I[15]顶-1.08E+11-3.13E+10-3.69E+101.37E+031.50E+0711916.916I[16]底0.00E+002.01E+102.21E+10-1.37E+031.04E+078224.816I[16]顶-1.40E+11-3.45E+10-4.07E+101.48E+031.54E+0712190.117I[17]底0.00E+001.80E+101.85E+10-1.20E+039.53E+067563.517I[17]顶-1.77E+11-3.78E+10-4.46E+101.62E+031.57E+0712427.718I[18]底0.00E+001.58E+101.50E+10-8.38E+029.47E+067516.392 18I[18]顶-2.19E+11-4.18E+10-4.93E+101.75E+031.62E+0712819.319I[19]底0.00E+001.38E+101.16E+10-4.65E+029.51E+067544.019I[19]顶-2.67E+11-4.64E+10-5.51E+101.92E+031.68E+0713365.920I[20]底-3.85E+091.38E+101.09E+10-2.93E+033.88E+063079.620I[20]顶-3.32E+11-5.26E+10-6.30E+102.18E+031.77E+0714021.921I[21]底-1.39E+081.36E+101.07E+10-2.57E+034.29E+063407.221I[21]顶-3.40E+11-5.37E+10-6.43E+102.35E+031.79E+0714174.222I[22]底-1.38E+081.39E+101.09E+10-2.57E+034.38E+063475.922I[22]顶-3.61E+11-5.58E+10-6.70E+102.36E+031.86E+0714765.023I[23]底-4.83E+091.37E+101.07E+10-2.57E+034.31E+063424.423I[23]顶-3.52E+11-5.28E+10-6.32E+102.35E+031.76E+0713930.224I[24]底-3.85E+091.35E+101.06E+10-2.93E+033.79E+063009.224I[24]顶-3.44E+11-5.17E+10-6.18E+102.18E+031.73E+0713763.025I[25]底0.00E+001.20E+109.35E+09-2.10E+034.34E+063446.625I[25]顶-2.81E+11-4.33E+10-5.08E+101.92E+031.55E+0712324.426I[26]底0.00E+001.19E+109.95E+09-2.33E+034.16E+063298.226I[26]顶-2.32E+11-3.66E+10-4.21E+101.76E+031.38E+0710936.627I[27]底0.00E+001.24E+101.14E+10-2.28E+034.51E+063581.027I[27]顶-1.88E+11-3.05E+10-3.43E+101.63E+031.21E+079569.028I[28]底0.00E+001.30E+101.29E+10-2.18E+035.02E+063981.928I[28]顶-1.49E+11-2.50E+10-2.74E+101.49E+031.04E+078228.929I[29]底0.00E+001.36E+101.45E+10-2.05E+035.92E+064698.429I[29]顶-1.16E+11-2.11E+10-2.26E+101.38E+039.19E+067297.230I[30]底0.00E+001.43E+101.63E+10-1.92E+037.22E+065733.230I[30]顶-8.57E+10-1.77E+10-1.87E+101.25E+038.28E+066570.831I[31]底0.00E+001.51E+101.82E+10-1.79E+038.76E+066949.731I[31]顶-6.03E+10-1.50E+10-1.57E+101.14E+037.53E+065978.232I[32]底0.00E+001.59E+102.02E+10-1.72E+031.04E+078241.132I[32]顶-3.96E+10-1.29E+10-1.34E+101.03E+036.91E+065486.192 33I[33]底0.00E+001.73E+102.27E+10-1.65E+031.22E+079658.433I[33]顶-2.30E+10-1.18E+10-1.25E+109.83E+026.70E+065315.734I[34]底9.15E+091.83E+102.46E+10-1.59E+031.37E+0710912.034I[34]顶-9.75E+09-1.08E+10-1.17E+108.24E+026.55E+065199.135I[35]底1.65E+101.91E+102.59E+10-1.53E+031.51E+0711965.135I[35]顶-1.62E+09-1.03E+10-1.11E+109.03E+026.49E+065147.936I[36]底1.95E+101.95E+102.65E+10-1.55E+031.61E+0712743.736I[36]顶0.00E+00-9.96E+09-1.07E+108.50E+026.47E+065133.437I[37]底1.96E+101.95E+102.65E+10-1.55E+031.61E+0712752.637I[37]顶0.00E+00-9.92E+09-1.06E+108.50E+026.43E+065105.238I[38]底1.97E+101.95E+102.65E+10-1.55E+031.61E+0712755.138I[38]顶0.00E+00-9.89E+09-1.06E+108.50E+026.41E+065088.35.2预应力束的布置本桥箱梁纵向预应力束采用φ15.24高强度低松弛预应力钢绞线，其公称面积140mm2，标准强度ƒpk=1860MPa，弹性模量Ep=1.95×105MPa，张拉控制应力σcon=0.75ƒpk=1395MPa。预应力管道均采用镀锌金属波纹管。锚具采用群锚体系OVM锚。锚垫板等预埋钢板采用低炭钢。连续梁桥预应力钢束的配置考虑以下原则：1)应选择适当的预应力束的型式与锚具型式，对不同跨径的梁桥结构，要选用预加力大小恰当的预应力束筋，以达到合理的布置型式。2)应力束筋的布置要考虑施工的方便，不能像在钢筋混凝土结构中任意切断钢筋那样去切断预应力束筋，从而导致在结构中布置过多的锚具。3)预应力束筋的布置，既要符合结构受力的要求，又要注意在超静定结构体系中避免引起过大的结构次内力。4)预应力束筋的布置，应考虑材料经济指标的先进性，这往往与桥梁体系、构造尺寸、施工方法的选择都有着密切关系。5)预应力束应避免使用多次反向曲率的连续束，因为这会引起很大的摩阻损失，降低预应力束的效益。6)预应力束的布置，不但要考虑结构在使用阶段的弹性受力状态的需要，而且也要考虑到结构在破坏阶段时的需要。7)预应力筋应使其中心线不超出束界范围，尽量对称布置，锚头应尽量靠近压应力区。92 8)预应力束一般应在距跨中三分点到四分点处开始弯起，弯起角不宜大于20°。钢绞线束当直径大/于5mm时弯起半径不宜小于6m。9)钢束在横断面中布置时，直束应尽量靠近顶板位置直接锚固于齿板上，弯束布置在腹板上便于下弯分散锚固。10)应留有一定数量的备用管道，一般占总数的1%。11)本桥中使用预埋波纹管，其水平净距不应小于40mm，且不小于管道直径的0.6倍，在竖直方向可叠置。波纹管到梁侧净距不小于35mm，到梁底距离不小于50mm。遵循上述的原则再结和全桥施工特点布筋。根据配筋数量要求及以上布置原则现将初步钢束具体布置绘图如下：图5-1梁端钢束布置断面图图5-2跨中钢束布置断面图5.3预应力损失计算根据《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTGD62-2004）规定，预应力混凝土构件在正常使用极限状态计算中，由于施工中预应力索的张拉采用后张法，应考虑由下列因素引起的预应力损失：预应力钢筋与管道壁之间的摩擦σl1锚具变形、钢筋回缩和接缝压缩σl2混凝土的弹性压缩σl492 预应力钢筋的应力松弛σl5混凝土的收缩和徐变σl65.3.1预应力与管道壁间摩擦引起的应力损失摩阻损失指的是预应力筋与管道间的摩察损失σl1,由规定，按以下公式计算：式中：σcon—张拉钢筋时锚下的控制应力（=0.75）；μ—预应力钢筋与管道壁的摩擦系数；θ—从张拉端至计算截面曲线管道部分切线的夹角之和，以rad计；k—管道每米局部偏差对摩擦的影响系数，取0.0015；x—从张拉端至计算截面的管道长度,以米计。表5.2系数k及μ的值管道类型Kμ橡胶管抽芯成型的管道0.00150.55铁皮套管0.00300.35金属波纹管0.0020～0.00300.20～0.265.3.2锚具变形、钢筋回缩和接缝压缩引起的应力损失锚具变形，钢筋回缩和拼装构件的接缝压缩损失σl2，在计算接缝压缩引起的应力损失时，认为接缝在第一批钢束锚固后既完成全部变形量，以后锚固得各批钢束对该接缝不再产生压缩。可按下式计算：式中：Dl—锚具变形、钢筋回缩和接缝压缩值；统一取6mm；L—预应力钢筋的有效长度；EP—预应力钢筋的弹性模量。取1.95×105MPa。5.3.3混凝土的弹性压缩引起的应力损失后张法构件一般采用分批张拉，张拉后批钢束时所产生的混凝土弹性压缩将使先批已张拉并锚固预应力钢筋产生应力损失，按下式计算：式中：—在计算截面上先张拉钢筋重心处，由后张拉各批钢筋所92 产生的混凝土法向应力之和；—预应力钢筋与混凝土的弹性模量之比。若逐一计算的值则甚为繁琐，可采用下列近似计算公式式中：N—计算截面上分批张拉的钢束批数.钢束重心处混凝土法向应力，可按下式计算：式中：M1为自重弯矩。注意此时计算Np时应考虑摩阻损失、锚具变形及钢筋回缩的影响。预应力损失产生时，预应力孔道还没压浆，截面特性取静截面特性（即扣除孔道部他的影响）。对悬臂拼装结构，作如下近似假设，可使先张拉钢束重心处由后张拉各批钢束产生的混凝土法向应力计算简化：1）每悬臂拼装一段，相应张拉一批力筋；假设每批张拉预应力都相同，且都作用在全部预应力重心处；2）在同一计算截面上，每一悬拼梁段自重所产生的自重弯矩都假设相等。5.3.4钢筋松弛引起的应力损失如果钢筋在一定拉应力值下，将其长度固定不变，则钢筋中的应力将随时间延长而降低，这种现象称为钢筋的应力松弛。此项应力损失可根据《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62—2004表6.2.6条的规定，按下列公式计算。对于钢丝、钢绞线，本设计中采用：=ψ·ξ式中：ψ—张拉系数，一次张拉时，ψ=1.0；超张拉时，ψ=0.9；ξ—钢筋松弛系数，Ⅰ级松弛（普通松弛），ξ=1.0；Ⅱ级松弛（低松弛），ξ=0.3；—传力锚固时的钢筋应力，对后张法构件=---；对先张法构件，=-。92 5.3.5收缩徐变损失由混凝土收缩和徐变引起的预应力钢筋应力损失，这种损失可由以下公式计算：式中：—构件受拉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；—构件受拉区全部纵向钢筋截面重心处由预应力和结构自重产生的混凝土法向应力；—构件受压区全部纵向钢筋截面重心处由预应力和结构自重产生的混凝土法向应力；—截面回转半径，，后张法采用净截面特性—构件受拉区预应力筋与非预应力筋截面重心至构件截面重心轴的距离；—构件受压区预应力筋与非预应力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、徐变，其终极值可按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62—2004中表6.2.7取用；—加载龄期为，计算考虑的龄期为t时的徐变系数，可按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62—2004中表6.2.7取用。92 表5.3T5钢束预应力损失表单元位置应力(瞬时损失):A(N/mm^2)弹性变形损失:B(N/mm^2)比值(A+B)/A徐变/收缩损失(N/mm^2)松弛损失(N/mm^2)应力(所有损失)/应力(瞬时损失)端部有效钢束数钢束组T5阶段成桥17I1083.593-27.8080.974-74.858-46.5300.862117J1162.190-26.1370.978-70.063-75.4420.852118I1162.190-25.8080.978-68.719-75.4420.854118J1151.946-18.2650.984-64.747-71.4770.866119I1151.946-18.1860.984-60.518-71.4770.870119J1086.141-13.0340.988-56.982-47.4130.892120I1086.141-12.4820.989-50.274-47.4130.899120J1082.563-8.2420.992-41.061-46.1730.912121I1082.563-19.7010.982-27.581-46.1730.914121J1073.668-17.7760.983-25.608-43.1240.919122I1073.668-17.7750.983-25.607-43.1240.919122J1082.563-19.8120.982-27.684-46.1730.914123I1082.563-8.3800.992-41.131-46.1730.912123J1086.141-12.6980.988-50.425-47.4130.898124I1086.141-13.1830.988-57.069-47.4130.892124J1151.946-18.8290.984-61.103-71.4780.869125I1151.946-19.0790.983-65.506-71.4780.865125J1162.190-27.1880.977-70.235-75.4420.851192 26I1162.190-28.6160.975-72.771-75.4420.848126J1083.594-32.7860.970-80.649-46.5300.85215.3.6有效预应力计算（使用阶段扣除全部损失的有效预应力值）（张拉锚固阶段的有效预应力）5.4预应力计算计算结果见下表。表5.4预应力计算表单元荷载阶段位置轴向(N)剪力-y(N)剪力-z(N)扭矩(N*mm)弯矩-y(N*mm)弯矩-z(N*mm)1钢束一次成桥I[1]-2.77E+0701.01E+06-1.06E+04-9.04E+09-2.98E+022钢束一次成桥I[2]-2.78E+0701.01E+06-1.05E+04-9.46E+095.46E+023钢束一次成桥I[3]-2.77E+0706.02E+06-9.91E+03-9.87E+093.77E+034钢束一次成桥I[4]-2.87E+0701.40E+06-9.68E+03-1.38E+101.65E+035钢束一次成桥I[5]-3.01E+0701.33E+06-3.50E+03-1.76E+10-1.04E+026钢束一次成桥I[6]-3.06E+0701.18E+05-2.52E+03-2.07E+108.17E+037钢束一次成桥I[7]-3.07E+070-2.37E+04-1.05E+03-2.08E+106.52E+038钢束一次成桥I[8]-3.58E+070-1.22E+064.86E+05-1.59E+10-1.05E+079钢束一次成桥I[9]-4.44E+070.39-4.12E+061.68E+06-1.32E+10-1.38E+0710钢束一次成桥I[10]-4.76E+070.6-5.11E+061.48E+06-1.40E+10-1.32E+0711钢束一次成桥I[11]-5.43E+070.14-5.52E+061.36E+06-1.11E+10-1.37E+0712钢束一次成桥I[12]-6.30E+073.09-7.53E+06-6.83E+059.44E+08-5.83E+0713钢束一次成桥I[13]-7.00E+07774.28-7.68E+061.76E+062.23E+108.19E+0614钢束一次成桥I[14]-7.65E+071230.67-8.68E+061.91E+064.50E+10-1.35E+0715钢束一次成桥I[15]-8.34E+07-97.26-1.00E+07-2.48E+056.97E+10-8.61E+0516钢束一次成桥I[16]-8.90E+07-0.41-1.21E+07-1.38E+049.69E+101.73E+0317钢束一次成桥I[17]-9.50E+070-1.31E+07-6.75E+011.32E+115.12E+0218钢束一次成桥I[18]-1.04E+080-1.39E+07-1.83E+021.64E+111.44E+0392 19钢束一次成桥I[19]-1.14E+080-1.57E+07-3.08E+022.03E+112.31E+0320钢束一次成桥I[20]-1.10E+080-3.46E+07-6.97E+022.44E+112.23E+0321钢束一次成桥I[21]-1.14E+080-1.22E+065.74E+002.71E+11-6.87E+0222钢束一次成桥I[22]-1.14E+0800.00E+000.00E+002.71E+11-3.26E+0323钢束一次成桥I[23]-1.10E+0803.39E+07-8.76E+022.63E+11-2.87E+0324钢束一次成桥I[24]-1.14E+0809.36E+06-2.95E+022.55E+11-3.75E+0325钢束一次成桥I[25]-1.09E+0801.02E+07-2.82E+021.96E+11-3.39E+0326钢束一次成桥I[26]-1.05E+0809.71E+06-2.62E+021.47E+11-3.02E+0327钢束一次成桥I[27]-1.00E+0808.58E+06-2.35E+021.07E+11-2.67E+0328钢束一次成桥I[28]-9.51E+0707.49E+06-2.09E+027.13E+10-2.32E+0329钢束一次成桥I[29]-9.06E+0705.43E+06-1.52E+024.27E+10-2.01E+0330钢束一次成桥I[30]-8.55E+0704.09E+06-1.19E+021.60E+10-1.66E+0331钢束一次成桥I[31]-8.01E+0703.69E+06-9.65E+01-6.35E+09-1.32E+0332钢束一次成桥I[32]-7.49E+0702.32E+06-6.91E+01-2.85E+10-1.07E+0333钢束一次成桥I[33]-6.95E+0701.78E+06-3.45E+01-4.57E+10-7.17E+0234钢束一次成桥I[34]-6.74E+0707.25E+051.43E+02-5.93E+10-6.59E+0235钢束一次成桥I[35]-6.21E+0705.77E+05-6.06E+00-7.20E+10-3.31E+0236钢束一次成桥I[36]-5.60E+070-5.42E+051.04E+00-7.72E+10-2.35E+0237钢束一次成桥I[37]-5.56E+0701.90E+05-4.90E-01-7.67E+10-2.33E+0238钢束一次成桥I[38]-5.56E+0701.89E+05-4.60E-01-7.67E+10-2.26E+0239钢束一次成桥I[39]-5.56E+0700.00E+000.00E+00-7.66E+10-2.62E+0140钢束一次成桥I[40]-5.54E+070-1.88E+054.90E-01-7.63E+10-3.42E+0141钢束一次成桥I[41]-5.53E+070-1.88E+055.20E-01-7.61E+10-3.96E+0142钢束一次成桥I[42]-6.01E+070-1.25E+063.75E+05-7.28E+10-1.65E+0743钢束一次成桥I[43]-6.17E+070.17-3.77E+061.13E+06-6.38E+10-1.69E+0744钢束一次成桥I[44]-6.24E+070.85-4.82E+061.21E+06-5.09E+10-1.61E+0745钢束一次成桥I[45]-6.70E+070.34-5.31E+061.30E+06-3.39E+10-1.69E+0746钢束一次成桥I[46]-7.01E+070-7.46E+065.30E+01-1.32E+10-3.37E+0247钢束一次成桥I[47]-7.64E+070-7.45E+062.71E+018.75E+09-2.15E+0292 48钢束一次成桥I[48]-8.12E+070-8.46E+069.06E+003.40E+10-8.20E+0149钢束一次成桥I[49]-8.75E+070-9.82E+06-1.06E+015.92E+108.12E+0150钢束一次成桥I[50]-9.63E+070-1.18E+07-3.44E+017.85E+102.57E+0251钢束一次成桥I[51]-1.03E+080-1.28E+07-5.60E+011.11E+114.54E+0252钢束一次成桥I[52]-1.10E+080-1.38E+07-8.27E+011.49E+116.67E+0253钢束一次成桥I[53]-1.14E+080-1.57E+07-1.21E+022.03E+119.05E+0254钢束一次成桥I[54]-1.10E+080-3.46E+07-2.93E+022.45E+119.38E+0255钢束一次成桥I[55]-1.14E+080-1.22E+06-8.00E+002.72E+119.58E+0256钢束一次成桥I[56]-1.14E+0800.00E+000.00E+002.71E+111.01E+0357钢束一次成桥I[57]-1.11E+0803.40E+072.79E+022.63E+119.14E+0258钢束一次成桥I[58]-1.15E+0809.38E+069.13E+012.55E+111.16E+0359钢束一次成桥I[59]-1.05E+0809.29E+068.56E+012.07E+111.03E+0360钢束一次成桥I[60]-9.55E+0708.88E+067.85E+011.71E+119.00E+0261钢束一次成桥I[61]-8.90E+0708.78E+067.20E+011.36E+117.91E+0262钢束一次成桥I[62]-8.28E+0707.83E+066.60E+011.01E+116.82E+0263钢束一次成桥I[63]-7.72E+0705.72E+063.98E+017.30E+105.82E+0264钢束一次成桥I[64]-7.06E+0704.42E+063.42E+014.73E+104.88E+0265钢束一次成桥I[65]-6.42E+0703.89E+062.27E+012.42E+103.91E+0266钢束一次成桥I[66]-5.53E+0701.83E+061.41E+015.49E+093.12E+0267钢束一次成桥I[67]-4.84E+0704.32E+055.08E+00-3.56E+092.11E+0268钢束一次成桥I[68]-4.57E+070-6.31E+053.07E+00-6.38E+091.37E+0269钢束一次成桥I[69]-3.58E+070-3.92E+043.80E-01-1.35E+107.27E+0170钢束一次成桥I[70]-3.08E+070-2.47E+05-3.30E-01-2.08E+103.68E+0171钢束一次成桥I[71]-3.07E+0702.37E+043.00E-02-2.07E+103.25E+0172钢束一次成桥I[72]-3.06E+070-8.77E+05-9.40E-01-2.07E+102.82E+0173钢束一次成桥I[73]-3.02E+070-1.09E+06-9.20E-01-1.76E+101.61E+0174钢束一次成桥I[74]-2.81E+070-6.10E+06-1.42E+00-1.30E+105.43E+0075钢束一次成桥I[75]-2.84E+070-9.04E+05-2.90E-01-1.08E+103.65E+0076钢束一次成桥I[76]-2.78E+070-1.01E+060.00E+00-9.46E+090.00E+0092 第六章强度验算6.1正截面承载能力验算在承载能力极限状态下，预应力混凝土梁沿着正截面和斜截面都有可能破坏，本设计只验算正截面的强度，斜截面强度忽略不计。翼缘位于受压区的T形截面或I形截面受弯构件，箱形截面受弯构件的正截面承载能力可参照T形截面计算，由于本设计未考虑普通钢筋，故其正截面抗弯承载能力按下列规定进行计算时也不考虑普通钢筋的影响，所以有：1）当符合下列条件时（6-1）应以宽度为的矩形截面按下面公式计算正截面抗弯承载力：（6-2）混凝土受压区高度x应按下式计算：（6-3）截面受压区高度应符合下列要求：（6-4）当受压区配有纵向普通钢筋和预应力钢筋，且预应力钢筋受压即（）为正时（6-5）当受压区仅配纵向普通钢筋或配普通钢筋和预应力钢筋，且预应力钢筋受拉即（）为负时（6-6）2）当不符合公式（6-1）的条件时，计算中应考虑截面腹板受压的作用，其正截面抗弯承载力应按下列规定计算：（6-7）92 此时，受压区高度应按下列公式计算，应应符合（6-4）、（6-5）、（6-6）的要求。（6-8）式中：—桥梁结构的重要性系数，按《公路钢筋混凝土及预应力混凝土设计规范》JTGD62-2004第5.1.5条的规定采用，本设计为二级，取=1.0；Md—弯矩组合设计值；—混凝土轴心抗压强度设计值，按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62-2004表3.1.4采用；—纵向预应力钢筋的抗拉强度设计值，按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62-2004表3.2.3-2采用；—受拉区纵向预应力钢筋的截面面积；—矩形截面宽度或T形截面腹板宽度，本设计应为箱形截面腹板总宽度；—截面有效高度，ɑ，此处h为截面全高；ɑ—受拉区普通钢筋和预应力钢筋的合力点至受拉区边缘的距离；—受压区普通钢筋和预应力钢筋的合力点至受压区边缘的距离；—受压区普通钢筋合力点至受压区边缘的距离；—T形或I形截面受压翼缘厚度；—T形或I形截面受压翼缘的有效宽度，按《公路钢筋混凝土及预应力混凝土设计规范》JTGD62-2004第4.2.2的规定采用。表6.1使用阶段正截面抗弯承载能力验算表单元位置最大/最小组合名称类型验算rMu(kN*m)Mn(kN*m)1I[1]最大cLCB2MY-MAXOK0.3251064.201I[1]最小cLCB12MY-MINOK0.2651064.202I[2]最大cLCB9FX-MINOK-40.3943214.092I[2]最小cLCB6MY-MINOK-599.6243214.093I[3]最大cLCB6MY-MAXOK7493.9751414.963I[3]最小cLCB11MY-MINOK2649.4251414.964I[4]最大cLCB6MY-MAXOK10643.0151444.374I[4]最小cLCB11MY-MINOK3885.2251444.375I[5]最大cLCB6MY-MAXOK24325.3152246.715I[5]最小cLCB11MY-MINOK7952.3052246.716I[6]最大cLCB6MY-MAXOK34877.4157993.886I[6]最小cLCB11MY-MINOK9953.8457993.887I[7]最大cLCB6MY-MAXOK38300.3358023.727I[7]最小cLCB11MY-MINOK10240.0958023.728I[8]最大cLCB6MY-MAXOK41282.6961825.288I[8]最小cLCB11MY-MINOK10244.0961825.289I[9]最大cLCB6MY-MAXOK48815.2273089.5392 9I[9]最小cLCB11MY-MINOK7427.1473089.5310I[10]最大cLCB6MY-MAXOK49294.9474788.8510I[10]最小cLCB11MY-MINOK15.9274788.8511I[11]最大cLCB6MY-MAXOK42703.0175521.7911I[11]最小cLCB11MY-MINOK-12076.72129995.1712I[12]最大cLCB12MY-MAXOK29357.46148802.8312I[12]最小cLCB5MY-MINOK-29279.82155658.6813I[13]最大cLCB12MY-MAXOK11918.6186734.1713I[13]最小cLCB5MY-MINOK-54615.79204180.4714I[14]最大cLCB12MY-MAXOK-12281.83257650.1914I[14]最小cLCB5MY-MINOK-86644.84257650.1915I[15]最大cLCB12MY-MAXOK-43612.05306391.9315I[15]最小cLCB5MY-MINOK-125873.98306391.9316I[16]最大cLCB12MY-MAXOK-79743.60349775.8116I[16]最小cLCB5MY-MINOK-169581.53349775.8117I[17]最大cLCB12MY-MAXOK-122553.33421311.4517I[17]最小cLCB5MY-MINOK-220540.28421311.4518I[18]最大cLCB12MY-MAXOK-171566.71459841.2718I[18]最小cLCB5MY-MINOK-279929.94459841.2719I[19]最大cLCB12MY-MAXOK-226959.86634001.9119I[19]最小cLCB5MY-MINOK-348316.23634001.9120I[20]最大cLCB12MY-MAXOK-294764.74786091.4320I[20]最小cLCB5MY-MINOK-437412.60786091.4321I[21]最大cLCB12MY-MAXOK-308729.69817829.0321I[21]最小cLCB5MY-MINOK-455312.01817829.0322I[22]最大cLCB12FX-MINOK-330580.70818708.8522I[22]最小cLCB5MY-MINOK-484739.67818708.8523I[23]最大cLCB12MY-MAXOK-302018.68817829.0323I[23]最小cLCB5MY-MINOK-446094.80817829.0324I[24]最大cLCB12MY-MAXOK-293111.35786091.4324I[24]最小cLCB5MY-MINOK-433676.19786091.4325I[25]最大cLCB12MY-MAXOK-222447.36655077.1325I[25]最小cLCB5MY-MINOK-335171.52655077.1326I[26]最大cLCB12MY-MAXOK-165699.46558142.0726I[26]最小cLCB5MY-MINOK-258274.72558142.0727I[27]最大cLCB12MY-MAXOK-114627.30473349.9327I[27]最小cLCB5MY-MINOK-190316.18473349.9328I[28]最大cLCB12MY-MAXOK-69673.51393586.9928I[28]最小cLCB5MY-MINOK-130841.91393586.9929I[29]最大cLCB12MY-MAXOK-30541.47323283.5929I[29]最小cLCB5MY-MINOK-80679.04323283.5930I[30]最大cLCB12MY-MAXOK5115.36140974.6930I[30]最小cLCB5MY-MINOK-36031.37255646.0331I[31]最大cLCB6MY-MAXOK37798.43145849.2231I[31]最小cLCB11MY-MINOK-2405.64192027.5932I[32]最大cLCB6MY-MAXOK66482.88152531.5532I[32]最小cLCB11MY-MINOK22137.30152531.5533I[33]最大cLCB6MY-MAXOK89779.00163174.7533I[33]最小cLCB11MY-MINOK40288.27163174.7592 34I[34]最大cLCB6MY-MAXOK106709.38175357.1834I[34]最小cLCB11MY-MINOK53486.32175357.1835I[35]最大cLCB6MY-MAXOK117367.45181933.1035I[35]最小cLCB11MY-MINOK61814.40181933.1036I[36]最大cLCB6MY-MAXOK121699.94184958.7136I[36]最小cLCB11MY-MINOK65390.86184958.7137I[37]最大cLCB6MY-MAXOK121797.45185075.4937I[37]最小cLCB11MY-MINOK65519.48185075.4938I[38]最大cLCB6MY-MAXOK121808.75185143.5438I[38]最小cLCB11MY-MINOK65562.79185143.546.2斜截面承载能力验算对配置箍筋及弯起预应力钢筋的矩形、T形和I形截面的预应力混凝土受弯构件，斜截面抗剪承载力的基本表达式为（6-9）式中：—斜截面受压端正截面上由作用（或荷载）产生的最大剪力组合设计值（KN）；—斜截面内混凝土和箍筋共同的抗剪承载力设计值（KN）；—与斜截面相交的预应力弯起钢筋抗剪承载力设计值（KN）。对于预应力混凝土连续梁等超静定结构，作用（或荷载）效应并考虑由预应力引起的次剪力；其中为作用（或荷载）效应（汽车荷载计入冲击系数）的组合设计值，为预应力（扣除全部预应力损失）引起的次效应；为预应力的荷载分项系数，当预应力对结构有利时，取=1.0；对结构不利时，取=1.2.对于箱型截面受弯构件的斜截面抗剪承载力的验算，也可参照上式（6-9）计算，右边为斜截面上各项抗剪承载力设计值之和，以下逐一介绍各项承载力的计算方法。1)斜截面内混凝土和箍筋共同的抗剪承载力设计值（）（KN）式中：—预应力提高系数，对预应力受弯构件，=1.25，允许出现裂缝的预应力混凝土受弯构件，取=1.0；—斜截面内受拉钢筋的计算配筋率。2)预应力弯起钢筋的抗剪承载力设计值（）预应力弯起钢筋的斜截面抗剪承载力计算按下式计算：92 （KN）式中：—预应力弯起钢筋（在斜截面受压端正截面处）的切线与水平线的夹角；—斜截面内在同一弯起平面内的预应力弯起钢筋的截面面积（mm2）—预应力钢筋抗拉强度设计值。表6.2使用阶段斜截面抗剪承载能力验算单元位置最大/最小组合名称类型验算rVd(kN)Vn(kN)截面验算剪力验算1I[1]最大cLCB8FZ-MAXOK-0.07913993.29OK跳过1I[1]最小cLCB5FZ-MINOK-0.096613654.64OK跳过2I[2]最大cLCB11FX-MINOK-2787.9811269.8OK跳过2I[2]最小cLCB6FZ-MINOK-7524.1711269.8OK跳过3I[3]最大cLCB11FX-MAXOK-2192.513143.22OK跳过3I[3]最小cLCB6FX-MINOK-6658.2313143.22OK跳过4I[4]最大cLCB11FX-MAXOK-2005.810617.25OK跳过4I[4]最小cLCB6FX-MINOK-6461.4710278.6OK验算5I[5]最大cLCB11FX-MAXOK-1114.9714652.59OK跳过5I[5]最小cLCB6FX-MINOK-5209.5511604.73OK跳过6I[6]最大cLCB11FZ-MAXOK-335.86917873.76OK跳过6I[6]最小cLCB6FZ-MINOK-4107.0317873.76OK验算7I[7]最大cLCB11FZ-MAXOK-46.925517774.69OK跳过7I[7]最小cLCB6FZ-MINOK-3696.7317774.69OK验算8I[8]最大cLCB11FX-MINOK242.895813887.13OK跳过8I[8]最小cLCB6FX-MAXOK-3287.3613887.13OK验算9I[9]最大cLCB5FX-MINOK1509.2516337.89OK跳过9I[9]最小cLCB12FX-MAXOK-1686.9316337.89OK跳过10I[10]最大cLCB5FX-MINOK3096.84117762.06OK验算10I[10]最小cLCB12FX-MAXOK-278.94717762.06OK跳过11I[11]最大cLCB5FX-MINOK4716.25514618.51OK验算11I[11]最小cLCB12FX-MAXOK1129.60818682.33OK跳过12I[12]最大cLCB5FX-MINOK6365.04813171.47OK验算12I[12]最小cLCB12FX-MAXOK2539.56621299.11OK跳过13I[13]最大cLCB5FX-MINOK8150.70918699.84OK验算13I[13]最小cLCB12FX-MAXOK4038.70716414.73OK跳过92 14I[14]最大cLCB5FX-MINOK10106.1822932.94OK验算14I[14]最小cLCB12FX-MAXOK5658.31220562.38OK跳过15I[15]最大cLCB5FX-MINOK1217126970.49OK验算15I[15]最小cLCB12FX-MAXOK7349.21225954.53OK验算16I[16]最大cLCB5FX-MINOK14211.3431418.7OK验算16I[16]最小cLCB12FX-MAXOK9004.83931080.04OK验算17I[17]最大cLCB5FX-MINOK16357.3234922.78OK验算17I[17]最小cLCB12FX-MAXOK10733.3934922.78OK验算18I[18]最大cLCB5FX-MINOK18614.238259.51OK验算18I[18]最小cLCB12FX-MAXOK12540.1538598.16OK验算19I[19]最大cLCB5FX-MINOK20970.8842826.58OK验算19I[19]最小cLCB12FX-MAXOK14418.9542826.58OK验算20I[20]最大cLCB5FZ-MAXOK22841.9464300.29OK验算20I[20]最小cLCB12FZ-MINOK15956.5664300.29OK验算21I[21]最大cLCB5FZ-MAXOK24258.9434010.87OK验算21I[21]最小cLCB12FZ-MINOK16951.4534010.87OK验算22I[22]最大cLCB11FX-MINOK-18864.932969.09OK验算22I[22]最小cLCB6FZ-MINOK-27055.932969.09OK验算23I[23]最大cLCB11FX-MAXOK-17185.466728.88OK验算23I[23]最小cLCB6FZ-MINOK-24775.766728.88OK验算24I[24]最大cLCB11FX-MAXOK-17567.438982.39OK验算24I[24]最小cLCB6FX-MINOK-25404.738643.74OK验算25I[25]最大cLCB11FX-MAXOK-15419.236580.58OK验算25I[25]最小cLCB6FX-MINOK-22626.435903.28OK验算26I[26]最大cLCB11FX-MAXOK-13609.832993.03OK验算26I[26]最小cLCB6FX-MINOK-20280.632654.38OK验算27I[27]最大cLCB11FX-MAXOK-11890.529716.59OK验算27I[27]最小cLCB6FX-MINOK-1804829039.28OK验算28I[28]最大cLCB11FX-MAXOK-10223.425036.38OK验算28I[28]最小cLCB6FX-MINOK-15923.625375.03OK验算29I[29]最大cLCB11FX-MAXOK-8618.5219634.83OK验算29I[29]最小cLCB6FX-MINOK-13903.220312.13OK验算30I[30]最大cLCB11FX-MAXOK-6986.5914107.98OK验算30I[30]最小cLCB6FX-MINOK-11857.215615.61OK验算92 31I[31]最大cLCB11FX-MAXOK-5430.1718498.66OK跳过31I[31]最小cLCB6FX-MINOK-9916.3914773.49OK验算32I[32]最大cLCB11FX-MAXOK-4005.1718934.26OK验算32I[32]最小cLCB6FX-MINOK-8151.5916563.7OK验算33I[33]最大cLCB11FX-MAXOK-2671.9417217.2OK跳过33I[33]最小cLCB6FX-MINOK-6512.7917217.2OK验算34I[34]最大cLCB11FX-MAXOK-1358.3417021.85OK跳过34I[34]最小cLCB6FX-MINOK-4916.3117021.85OK验算35I[35]最大cLCB11FX-MAXOK-35.352214917.75OK跳过35I[35]最小cLCB6FX-MINOK-3328.1414917.75OK验算36I[36]最大cLCB11FZ-MAXOK1266.93618946.6OK跳过36I[36]最小cLCB6FZ-MINOK-1785.118946.6OK跳过37I[37]最大cLCB11FZ-MAXOK1429.45818576.96OK跳过37I[37]最小cLCB6FZ-MINOK-1593.9118576.96OK跳过38I[38]最大cLCB5FZ-MAXOK1532.4218578.98OK跳过38I[38]最小cLCB12FZ-MINOK-1484.6418578.98OK跳过92 第七章应力验算预应力混凝土连续梁在各个受力阶段均有其不同受力特点。从一开始施加预应力，其预应力钢筋和混凝土就开始处于高应力状态下。为保证构件在各个阶段的安全，除了要进行强度验算外，还必须对其施工和使用阶段的应力情况分别进行验算。7.1短暂状况预应力混凝土受弯构件应力验算预应力混凝土受弯构件按短暂状况计算时,预应力钢筋应扣除相应阶段的预应力损失，荷载采用施工荷载，截面性质采用净截面。在预应力和构件自重等施工荷载作用下截面边缘混凝土的法向应力应符合下列规定：7.1.1压应力验算式中:—按短暂状况计算时截面预压区边缘混凝土的压应力；—与制作、运输、安装各施工阶段混凝土立方体抗压强度相应的抗压强度标准值。7.1.2拉应力验算当时，预拉区应配置其配筋率不小于0.2％的纵向钢筋；当时，预拉区应配置其配筋率不小于0.4％的纵向钢筋；当时，预拉区应配置的纵向钢筋配筋率按以上两者直线内差取用。式中:—按短暂状况计算时截面预拉区边缘混凝土的拉应力；—与制作、运输、安装各施工阶段混凝土立方体抗压强度相应的抗压强度、抗拉强度标准值。表7.1施工阶段法向压应力验算（顶板）单位置最大/阶段验Sig_TSig_TLSig_TRSig_MAXSig_ALW92 元最小算(N/mm^2)(N/mm^2)(N/mm^2)(N/mm^2)(N/mm^2)1I[1]最大安装支座OK0.7890.7890.7892.53119.8801I[1]最小边跨满堂支架OK-0.009-0.009-0.009-0.009-1.5342I[2]最大安装支座OK0.7550.7550.7552.58319.8802I[2]最小边跨满堂支架OK-0.009-0.009-0.009-0.009-1.5343I[3]最大安装支座OK1.0331.0331.0332.28319.8803I[3]最小边跨满堂支架OK-0.009-0.009-0.009-0.009-1.5344I[4]最大安装支座OK1.3851.3851.3853.40819.8804I[4]最小边跨满堂支架OK-0.014-0.014-0.014-0.014-1.7265I[5]最大安装支座OK1.9641.9641.9643.71119.8805I[5]最小边跨满堂支架OK-0.017-0.017-0.017-0.017-1.8996I[6]最大安装支座OK2.4892.4892.4894.26719.8806I[6]最小中跨合拢OK0.7030.7030.7030.703-1.5347I[7]最大安装支座OK2.6462.6462.6464.07119.8807I[7]最小中跨合拢OK0.8790.8790.8790.835-1.5348I[8]最大安装支座OK4.6914.6924.6904.69219.8808I[8]最小11号块成材OK2.0212.0212.021-0.216-2.5219I[9]最大安装支座OK6.5166.5176.5156.51719.8809I[9]最小11号块成材OK3.8113.8123.8110.958-1.53410I[10]最大安装支座OK5.3725.3735.3715.37319.88010I[10]最小10号块浇筑OK0.6440.6440.6440.644-1.53411I[11]最大安装支座OK5.1115.1125.1105.44519.88011I[11]最小9号块浇筑OK0.4160.4160.4160.416-1.53412I[12]最大安装支座OK6.0806.0836.0766.08319.88012I[12]最小8号块浇筑OK0.3290.3290.3290.329-1.53413I[13]最大安装支座OK6.2596.2586.2596.25919.88013I[13]最小7号块浇筑OK0.3090.3090.3090.309-1.53414I[14]最大11号块浇筑OK3.7183.7183.7186.58719.88014I[14]最小6号块浇筑OK0.3040.3040.3040.304-1.53415I[15]最大11号块浇筑OK3.8013.8013.8017.46919.88015I[15]最小5号块浇筑OK0.2560.2560.2560.256-1.53416I[16]最大11号块浇筑OK3.7483.7483.7488.26719.88016I[16]最小4号块浇筑OK0.2050.2050.2050.205-1.53417I[17]最大11号块浇筑OK3.8463.8463.8468.83419.88017I[17]最小3号块浇筑OK0.1670.1670.1670.167-1.53418I[18]最大11号块浇筑OK3.9963.9963.9969.21419.88018I[18]最小2号块浇筑OK0.3220.3220.3220.322-1.53419I[19]最大11号块浇筑OK4.1744.1744.1749.47219.88019I[19]最小1号块浇筑OK0.4360.4360.4360.436-1.53420I[20]最大11号块浇筑OK3.4943.4943.4949.38019.88020I[20]最小0号块施工OK1.0931.0931.0930.120-1.53421I[21]最大成桥OK3.4203.4203.4204.88019.88021I[21]最小中跨合拢OK-0.159-0.159-0.159-0.201-1.53492 22I[22]最大成桥OK2.9442.9442.9445.40619.88022I[22]最小中跨合拢OK-0.245-0.245-0.245-0.245-1.53423I[23]最大11号块浇筑OK1.9731.9731.9736.78319.88023I[23]最小0号块施工OK0.8570.8570.8570.012-1.53424I[24]最大11号块浇筑OK3.4563.4563.4569.63119.88024I[24]最小0号块施工OK1.1771.1771.1770.098-1.53425I[25]最大11号块浇筑OK3.3573.3573.3579.41419.88025I[25]最小1号块成材OK1.0121.0121.0120.260-1.53426I[26]最大11号块浇筑OK3.2723.2723.2728.97519.88026I[26]最小2号块成材OK0.9320.9320.9320.409-1.53427I[27]最大11号块浇筑OK3.2543.2543.2548.34419.88027I[27]最小4号块成材OK2.4182.4182.4180.261-1.53428I[28]最大11号块浇筑OK3.1203.1203.1207.72919.88028I[28]最小4号块成材OK1.2331.2331.2330.200-1.53429I[29]最大11号块浇筑OK3.1343.1343.1346.88419.88029I[29]最小5号块成材OK1.5071.5071.5070.055-1.53430I[30]最大安装支座OK6.9716.9716.9716.97119.88030I[30]最小6号块成材OK1.5941.5941.5940.064-1.53431I[31]最大安装支座OK7.0517.0517.0517.05119.88031I[31]最小7号块成材OK1.6611.6611.6610.079-1.53432I[32]最大安装支座OK7.4187.4187.4187.41819.88032I[32]最小8号块成材OK1.9771.9771.977-0.036-2.02633I[33]最大安装支座OK6.7896.7896.7896.78919.88033I[33]最小9号块成材OK2.0152.0152.015-0.097-2.05934I[34]最大安装支座OK6.6546.6546.6547.32119.88034I[34]最小10号块成材OK2.3052.3052.305-0.042-2.09235I[35]最大安装支座OK5.5125.5125.5127.75519.88035I[35]最小11号块成材OK1.2131.2131.213-0.021-2.12436I[36]最大安装支座OK4.4624.4624.4627.73319.88036I[36]最小中跨合拢OK2.1252.1252.1252.125-1.53437I[37]最大安装支座OK4.4854.4854.4857.58719.88037I[37]最小中跨合拢OK2.1442.1442.1442.144-1.53438I[38]最大安装支座OK4.4844.4844.4847.58319.88038I[38]最小中跨合拢OK2.1412.1412.1412.141-1.534表7.2施工阶段法向压应力验算（底板）单元位置最大/最小阶段验算Sig_B(N/mm^2)Sig_BL(N/mm^2)Sig_BR(N/mm^2)Sig_MAX(N/mm^2)Sig_ALW(N/mm^2)1I[1]最大安装支座OK2.5312.5312.5312.53119.88092 1I[1]最小边跨满堂支架OK0.0090.0090.009-0.009-1.5342I[2]最大安装支座OK2.5832.5832.5832.58319.8802I[2]最小边跨满堂支架OK0.0090.0090.009-0.009-1.5343I[3]最大安装支座OK2.2832.2832.2832.28319.8803I[3]最小边跨满堂支架OK0.0110.0110.011-0.009-1.5344I[4]最大安装支座OK3.4083.4083.4083.40819.8804I[4]最小边跨满堂支架OK0.0140.0140.014-0.014-1.7265I[5]最大安装支座OK3.7113.7113.7113.71119.8805I[5]最小边跨满堂支架OK0.0160.0160.016-0.017-1.8996I[6]最大安装支座OK4.2674.2674.2674.26719.8806I[6]最小中跨合拢OK1.0631.0631.0630.703-1.5347I[7]最大安装支座OK4.0714.0714.0714.07119.8807I[7]最小中跨合拢OK0.8350.8350.8350.835-1.5348I[8]最大安装支座OK3.6463.6463.6454.69219.8808I[8]最小11号块成材OK-0.216-0.216-0.216-0.216-2.5219I[9]最大安装支座OK4.2194.2194.2186.51719.8809I[9]最小11号块成材OK0.9580.9580.9580.958-1.53410I[10]最大安装支座OK4.6874.6884.6875.37319.88010I[10]最小10号块浇筑OK1.5281.5281.5280.644-1.53411I[11]最大安装支座OK5.4455.4455.4445.44519.88011I[11]最小9号块浇筑OK1.7231.7231.7230.416-1.53412I[12]最大安装支座OK6.0436.0456.0416.08319.88012I[12]最小8号块浇筑OK1.8191.8191.8190.329-1.53413I[13]最大安装支座OK5.0395.0395.0396.25919.88013I[13]最小7号块浇筑OK1.4811.4811.4810.309-1.53414I[14]最大11号块浇筑OK6.5876.5876.5876.58719.88014I[14]最小6号块浇筑OK1.3881.3881.3880.304-1.53415I[15]最大11号块浇筑OK7.4697.4697.4697.46919.88015I[15]最小5号块浇筑OK1.3831.3831.3830.256-1.53416I[16]最大11号块浇筑OK8.2678.2678.2678.26719.88016I[16]最小4号块浇筑OK1.3451.3451.3450.205-1.53417I[17]最大11号块浇筑OK8.8348.8348.8348.83419.88017I[17]最小3号块浇筑OK1.2911.2911.2910.167-1.53418I[18]最大11号块浇筑OK9.2149.2149.2149.21419.88018I[18]最小2号块浇筑OK0.9730.9730.9730.322-1.53419I[19]最大11号块浇筑OK9.4729.4729.4729.47219.88019I[19]最小1号块浇筑OK0.7120.7120.7120.436-1.53420I[20]最大11号块浇筑OK9.3809.3809.3809.38019.88020I[20]最小0号块施工OK0.1200.1200.1200.120-1.53421I[21]最大成桥OK4.8804.8804.8804.88019.88021I[21]最小中跨合拢OK-0.201-0.201-0.201-0.201-1.53422I[22]最大成桥OK5.4065.4065.4065.40619.88022I[22]最小中跨合拢OK-0.177-0.177-0.177-0.245-1.53492 23I[23]最大11号块浇筑OK6.7836.7836.7836.78319.88023I[23]最小0号块施工OK0.0120.0120.0120.012-1.53424I[24]最大11号块浇筑OK9.6319.6319.6319.63119.88024I[24]最小0号块施工OK0.0980.0980.0980.098-1.53425I[25]最大11号块浇筑OK9.4149.4149.4149.41419.88025I[25]最小1号块成材OK0.2600.2600.2600.260-1.53426I[26]最大11号块浇筑OK8.9758.9758.9758.97519.88026I[26]最小2号块成材OK0.4090.4090.4090.409-1.53427I[27]最大11号块浇筑OK8.3448.3448.3448.34419.88027I[27]最小4号块成材OK0.2610.2610.2610.261-1.53428I[28]最大11号块浇筑OK7.7297.7297.7297.72919.88028I[28]最小4号块成材OK0.2000.2000.2000.200-1.53429I[29]最大11号块浇筑OK6.8846.8846.8846.88419.88029I[29]最小5号块成材OK0.0550.0550.0550.055-1.53430I[30]最大安装支座OK6.1146.1146.1146.97119.88030I[30]最小6号块成材OK0.0640.0640.0640.064-1.53431I[31]最大安装支座OK5.9025.9025.9027.05119.88031I[31]最小7号块成材OK0.0790.0790.0790.079-1.53432I[32]最大安装支座OK6.7746.7746.7747.41819.88032I[32]最小8号块成材OK-0.036-0.036-0.036-0.036-2.02633I[33]最大安装支座OK6.7186.7186.7186.78919.88033I[33]最小9号块成材OK-0.097-0.097-0.097-0.097-2.05934I[34]最大安装支座OK7.3217.3217.3217.32119.88034I[34]最小10号块成材OK-0.042-0.042-0.042-0.042-2.09235I[35]最大安装支座OK7.7557.7557.7557.75519.88035I[35]最小11号块成材OK-0.021-0.021-0.021-0.021-2.12436I[36]最大安装支座OK7.7337.7337.7337.73319.88036I[36]最小中跨合拢OK3.5123.5123.5122.125-1.53437I[37]最大安装支座OK7.5877.5877.5877.58719.88037I[37]最小中跨合拢OK3.3583.3583.3582.144-1.53438I[38]最大安装支座OK7.5837.5837.5837.58319.88038I[38]最小中跨合拢OK3.3443.3443.3442.141-1.5347.2持久状况正常使用极限状态应力验算7.2.1持久状况（使用阶段）预应力混凝土受压区混凝土最大压应力验算持久状况（使用阶段）预应力混凝土受压区混凝土最大压应力可按下式计算：（6-10）92 ，（6-11）式中：—由预加力产生的混凝土法向拉应力；—混凝土法向压应力；—按荷载标准值组合计算的弯矩值；注：后张法构件在计算预施应力阶段由构件自重产生的法向拉（压）应力时，可改用。表7.3使用阶段混凝土最大压应力验算单元位置组合名称类型验算Sig_T(N/mm^2)Sig_B(N/mm^2)Sig_TL(N/mm^2)Sig_BL(N/mm^2)Sig_TR(N/mm^2)Sig_BR(N/mm^2)Sig_MAX(N/mm^2)Sig_ALW(N/mm^2)1I[1]cLCB22MZ-MINOK0.762.410.762.410.762.412.4117.752I[2]cLCB23MY-MINOK0.702.490.702.490.702.492.4917.753I[3]cLCB23MY-MINOK0.942.220.942.220.942.222.2217.754I[4]cLCB23MY-MINOK1.253.271.253.271.253.273.2717.755I[5]cLCB23MY-MINOK1.653.711.653.711.653.713.7117.756I[6]cLCB23MY-MINOK1.964.481.964.481.964.484.4817.757I[7]cLCB23MY-MINOK2.044.432.044.432.044.434.4317.758I[8]cLCB24MY-MAXOK5.940.785.940.785.930.785.9417.759I[9]cLCB24MY-MAXOK8.020.848.020.848.020.848.0217.7510I[10]cLCB24MY-MAXOK7.051.157.051.157.051.157.0517.7511I[11]cLCB23MY-MINOK3.457.233.457.243.457.237.2417.7512I[12]cLCB23MY-MINOK4.058.314.068.314.058.318.3117.7513I[13]cLCB23MY-MINOK4.067.524.067.524.067.527.5217.7514I[14]cLCB23MY-MINOK4.247.644.257.644.247.637.6417.7515I[15]cLCB23MY-MINOK4.257.954.257.954.257.957.9517.7516I[16]cLCB23MY-MINOK4.168.184.168.184.168.188.1817.7517I[17]cLCB23MY-MINOK4.208.244.208.244.208.248.2417.7518I[18]cLCB23MY-MINOK4.168.834.168.834.168.838.8317.7519I[19]cLCB23MY-MINOK4.179.304.179.304.179.309.3017.7520I[20]cLCB23MY-MINOK3.409.483.409.483.409.479.4817.7592 21I[21]cLCB23MY-MINOK2.286.232.286.232.286.236.2317.7522I[22]cLCB23MY-MINOK1.756.811.766.811.756.816.8117.7523I[23]cLCB23MY-MINOK2.336.422.336.422.326.416.4217.7524I[24]cLCB23MY-MINOK3.749.093.749.093.739.099.0917.7525I[25]cLCB23MY-MINOK3.998.933.998.933.998.938.9317.7526I[26]cLCB23MY-MINOK4.178.854.178.854.178.858.8517.7527I[27]cLCB23MY-MINOK4.478.554.478.554.468.558.5517.7528I[28]cLCB23MY-MINOK4.718.254.728.264.718.258.2617.7529I[29]cLCB23MY-MINOK5.107.815.107.815.107.817.8117.7530I[30]cLCB24MY-MAXOK7.364.567.364.567.364.567.3617.7531I[31]cLCB24MY-MAXOK7.813.727.813.727.813.727.8117.7532I[32]cLCB24MY-MAXOK8.573.608.573.618.573.608.5717.7533I[33]cLCB24MY-MAXOK8.412.828.412.828.412.828.4117.7534I[34]cLCB24MY-MAXOK8.682.678.692.688.682.678.6917.7535I[35]cLCB24MY-MAXOK7.962.407.962.407.962.407.9617.7536I[36]cLCB24MY-MAXOK7.251.807.251.807.251.807.2517.7537I[37]cLCB24MY-MAXOK7.261.787.261.787.251.787.2617.7538I[38]cLCB24MY-MAXOK7.222.047.232.047.222.037.2317.7539I[39]cLCB24MY-MAXOK7.222.037.232.037.222.037.2317.7540I[40]cLCB24MY-MAXOK7.261.727.261.727.261.727.2617.7541I[41]cLCB24MY-MAXOK7.271.607.281.607.271.607.2817.7542I[42]cLCB24MY-MAXOK8.091.698.101.698.091.698.1017.7543I[43]cLCB24MY-MAXOK8.481.708.481.708.481.708.4817.7544I[44]cLCB24MY-MAXOK8.391.418.391.418.381.418.3917.7545I[45]cLCB24MY-MAXOK8.781.688.791.688.781.678.7917.7546I[46]cLCB24MY-MAXOK9.062.039.062.039.052.039.0617.7547I[47]cLCB24MY-MAXOK8.282.508.282.508.282.508.2817.7548I[48]cLCB24MY-MAXOK7.823.257.823.257.823.257.8217.7549I[49]cLCB24MY-MAXOK7.264.337.264.337.264.327.2617.7550I[50]cLCB23MY-MINOK4.868.254.878.264.868.258.2617.7551I[51]cLCB23MY-MINOK4.548.834.548.834.548.838.8317.7552I[52]cLCB23MY-MINOK4.309.334.309.334.309.339.3317.7553I[53]cLCB23MY-MINOK4.259.204.269.204.259.209.2017.7554I[54]cLCB23MY-MINOK3.309.683.319.683.299.679.6817.7592 55I[55]cLCB23MY-MINOK2.166.372.166.382.166.376.3817.7556I[56]cLCB23MY-MINOK1.597.011.597.011.597.017.0117.7557I[57]cLCB23MY-MINOK2.126.652.126.652.126.656.6517.7558I[58]cLCB23MY-MINOK3.489.443.499.443.489.449.4417.7559I[59]cLCB23MY-MINOK3.568.983.568.983.568.988.9817.7560I[60]cLCB23MY-MINOK3.668.313.668.313.668.318.3117.7561I[61]cLCB23MY-MINOK3.797.953.807.953.797.957.9517.7562I[62]cLCB23MY-MINOK3.717.873.717.873.717.877.8717.7563I[63]cLCB23MY-MINOK3.767.653.767.653.767.657.6517.7564I[64]cLCB23MY-MINOK3.707.383.707.383.707.387.3817.7565I[65]cLCB23MY-MINOK3.497.263.497.263.497.267.2617.7566I[66]cLCB23MY-MINOK3.457.463.457.463.457.467.4617.7567I[67]cLCB24MY-MAXOK7.091.217.091.217.091.217.0917.7568I[68]cLCB24MY-MAXOK8.400.838.400.838.400.838.4017.7569I[69]cLCB24MY-MAXOK6.67-0.036.67-0.036.67-0.036.6717.7570I[70]cLCB23MY-MINOK1.954.601.954.601.954.604.6017.7571I[71]cLCB23MY-MINOK1.934.591.934.591.934.594.5917.7572I[72]cLCB23MY-MINOK1.924.681.924.681.924.684.6817.7573I[73]cLCB23MY-MINOK1.603.811.603.811.603.813.8117.7574I[74]cLCB23MY-MINOK1.283.211.283.211.283.213.2117.7575I[75]cLCB23MY-MINOK0.872.340.872.340.872.342.3417.7576I[76]cLCB22MY-MINOK0.702.490.702.490.702.492.4917.757.2.2持久状况（使用阶段）混凝土的主压应力验算混凝土的主压应力应符合下式规定：式中：—混凝土轴心抗压强度标准值表7.4使用阶段混凝土主压应力验算单元位置组合名称类型验算Sig_P1(N/mm^2)Sig_P3(N/mm^2)Sig_P4(N/mm^2)Sig_P7(N/mm^2)Sig_P8(N/mm^2)Sig_P10(N/mm^2)Sig_MAX(N/mm^2)Sig_AP(N/mm^2)92 1I[1]cLCB22MZ-MINOK0.762.412.411.501.501.372.4121.302I[2]cLCB23MY-MINOK0.702.492.491.721.711.592.4921.303I[3]cLCB23MY-MINOK0.942.222.221.701.701.602.2221.304I[4]cLCB23MY-MINOK1.253.273.272.092.091.923.2721.305I[5]cLCB23MY-MINOK1.653.713.712.462.462.243.7121.306I[6]cLCB23MY-MINOK1.964.484.482.922.922.634.4821.307I[7]cLCB23MY-MINOK2.044.434.432.932.932.654.4321.308I[8]cLCB24MY-MAXOK5.940.780.784.414.414.965.9421.309I[9]cLCB24MY-MAXOK8.020.840.846.356.357.168.0221.3010I[10]cLCB24MY-MAXOK7.051.151.155.305.316.097.0521.3011I[11]cLCB23MY-MINOK3.457.237.245.045.044.447.2421.3012I[12]cLCB23MY-MINOK4.068.318.315.905.905.198.3121.3013I[13]cLCB23MY-MINOK4.067.527.525.505.504.807.5221.3014I[14]cLCB23MY-MINOK4.257.637.645.655.654.927.6421.3015I[15]cLCB23MY-MINOK4.257.957.955.795.794.957.9521.3016I[16]cLCB23MY-MINOK4.168.188.185.865.864.908.1821.3017I[17]cLCB23MY-MINOK4.208.248.245.915.914.918.2421.3018I[18]cLCB23MY-MINOK4.168.838.836.146.144.948.8321.3019I[19]cLCB23MY-MINOK4.179.309.306.376.375.009.3021.3020I[20]cLCB23MY-MINOK3.409.479.486.866.865.129.4821.3021I[21]cLCB23MY-MINOK2.286.236.234.504.493.316.2321.3022I[22]cLCB23MY-MINOK1.766.816.814.684.673.196.8121.3023I[23]cLCB23MY-MINOK2.336.416.424.564.563.356.4221.3024I[24]cLCB23MY-MINOK3.749.099.096.346.334.799.0921.3025I[25]cLCB23MY-MINOK3.998.938.936.266.254.938.9321.3026I[26]cLCB23MY-MINOK4.178.858.856.276.265.068.8521.3027I[27]cLCB23MY-MINOK4.478.558.556.296.285.268.5521.3028I[28]cLCB23MY-MINOK4.728.258.266.286.275.428.2621.3029I[29]cLCB23MY-MINOK5.107.817.816.336.325.707.8121.3030I[30]cLCB24MY-MAXOK7.364.564.566.276.276.877.3621.3031I[31]cLCB24MY-MAXOK7.813.723.726.186.187.017.8121.3032I[32]cLCB24MY-MAXOK8.573.603.616.726.717.578.5721.3033I[33]cLCB24MY-MAXOK8.412.822.826.296.297.208.4121.3034I[34]cLCB24MY-MAXOK8.692.672.686.406.407.318.6921.3092 35I[35]cLCB24MY-MAXOK7.962.402.405.835.836.617.9621.3036I[36]cLCB24MY-MAXOK7.251.801.805.175.175.867.2521.3037I[37]cLCB24MY-MAXOK7.261.781.785.185.185.877.2621.3038I[38]cLCB24MY-MAXOK7.232.032.045.265.265.927.2321.3039I[39]cLCB24MY-MAXOK7.232.032.035.255.255.917.2321.3040I[40]cLCB24MY-MAXOK7.261.721.725.165.155.867.2621.3041I[41]cLCB24MY-MAXOK7.281.601.605.125.125.847.2821.3042I[42]cLCB24MY-MAXOK8.101.691.695.655.656.478.1021.3043I[43]cLCB24MY-MAXOK8.481.701.705.965.976.918.4821.3044I[44]cLCB24MY-MAXOK8.391.411.415.745.746.808.3921.3045I[45]cLCB24MY-MAXOK8.791.671.686.026.027.198.7921.3046I[46]cLCB24MY-MAXOK9.062.032.036.376.387.599.0621.3047I[47]cLCB24MY-MAXOK8.282.502.505.945.947.128.2821.3048I[48]cLCB24MY-MAXOK7.823.253.255.945.946.947.8221.3049I[49]cLCB24MY-MAXOK7.264.324.336.046.046.727.2621.3050I[50]cLCB23MY-MINOK4.878.258.266.286.285.478.2621.3051I[51]cLCB23MY-MINOK4.548.838.836.356.355.288.8321.3052I[52]cLCB23MY-MINOK4.309.339.336.456.445.149.3321.3053I[53]cLCB23MY-MINOK4.269.209.206.386.375.069.2021.3054I[54]cLCB23MY-MINOK3.319.679.686.756.764.959.6821.3055I[55]cLCB23MY-MINOK2.166.376.384.594.583.326.3821.3056I[56]cLCB23MY-MINOK1.597.017.014.604.603.047.0121.3057I[57]cLCB23MY-MINOK2.126.656.654.634.633.296.6521.3058I[58]cLCB23MY-MINOK3.499.449.446.286.274.569.4421.3059I[59]cLCB23MY-MINOK3.568.988.986.006.004.578.9821.3060I[60]cLCB23MY-MINOK3.668.318.315.725.724.528.3121.3061I[61]cLCB23MY-MINOK3.807.957.955.585.584.557.9521.3062I[62]cLCB23MY-MINOK3.717.877.875.475.474.487.8721.3063I[63]cLCB23MY-MINOK3.767.657.655.425.424.547.6521.3064I[64]cLCB23MY-MINOK3.707.387.385.265.264.477.3821.3065I[65]cLCB23MY-MINOK3.497.267.265.055.054.297.2621.3066I[66]cLCB23MY-MINOK3.457.467.465.185.184.517.4621.3067I[67]cLCB24MY-MAXOK7.091.211.214.884.885.807.0921.3068I[68]cLCB24MY-MAXOK8.400.830.835.555.556.648.4021.3092 69I[69]cLCB24MY-MAXOK6.670.010.014.174.175.046.6721.3070I[70]cLCB23MY-MINOK1.954.604.602.942.942.644.6021.3071I[71]cLCB23MY-MINOK1.934.594.592.922.922.614.5921.3072I[72]cLCB23MY-MINOK1.924.684.682.972.962.654.6821.3073I[73]cLCB23MY-MINOK1.603.813.812.472.472.243.8121.3074I[74]cLCB23MY-MINOK1.283.213.212.482.482.333.2121.3075I[75]cLCB23MY-MINOK0.872.342.341.561.561.442.3421.3076I[76]cLCB22MY-MINOK0.702.492.491.591.581.452.4921.307.2.3持久状况（使用阶段）预应力钢筋拉应力验算式中：—预应力钢筋弹性模量与混凝土弹性模量的比值；—受拉区预应力钢筋扣除全部预应力损失后的有效应力；—按荷载效应标准值计算的预应力钢筋重心处混凝土的法向应力；—预应力钢筋应力。表7.5使用阶段受拉钢筋拉应力验算钢束验算Sig_DL(N/mm^2)Sig_LL(N/mm^2)Sig_ADL(N/mm^2)Sig_ALL(N/mm^2)B1OK1167.4621091.90713951209B2OK1028.5691057.34113951209B3OK1027.9221057.16713951209B4OK1110.1211071.91213951209BBOK1166.481091.26213951209H1OK1078.4851063.5613951209H21OK1102.2191063.5613951209H22OK1102.2191063.5613951209H3OK1057.4711055.60913951209T1OK1052.7881072.2011395120992 T10OK1073.4691004.54213951209T11OK1079.6431015.10113951209T12OK997.41841019.33713951209T13OK1055.4571017.27413951209T14OK958.61051006.5113951209T15OK1041.3041018.57413951209T16OK937.0393997.693513951209T17OK1039.1671016.67613951209T18OK941.6198995.454313951209T19OK996.91541013.73713951209T2OK1004.3181035.39613951209T20OK906.2149994.299113951209T21OK992.48781022.88313951209T22OK879.3352985.730713951209T23OK1006.6181028.29513951209T24OK07.556313951209T3OK1076.3121010.73713951209T4OK1039.6691010.26313951209T5OK1083.5941007.38413951209T6OK1083.4471000.3813951209T7OK1085.761995.18513951209T8OK1083.876998.026413951209T9OK1076.521993.929913951209Z1OK1051.4321044.0413951209Z10OK964.34281035.37113951209Z2OK987.50451021.9413951209Z3OK992.05271017.11213951209Z4OK974.53911025.46213951209Z5OK968.85081025.99513951209Z6OK977.00321027.50613951209Z7OK974.99421034.86313951209Z8OK964.4781030.84213951209Z9OK966.57451036.92713951209ZBOK985.79351048.7071395120992 第八章抗裂验算8.1正截面抗裂验算正截面抗裂应对构件正截面混凝土的拉应力进行验算，并应符合下列要求：1）全预应力混凝土构件，在作用（或荷载）短期效应组合下预制构件分段浇筑或砂浆接缝的纵向分块构件式中：—为在短期荷载效应组合作用下，截面受拉边的应力：—为截面受拉区的有效预压应力：92 ，2）A类预应力混凝土构件，在作用（或荷载）短期效应组合下但在荷载长期效应组合下表8.1使用阶段正截面抗裂性验算单元位置组合名称短/长类型验算Sig_T(N/mm^2)Sig_B(N/mm^2)Sig_TL(N/mm^2)Sig_BL(N/mm^2)Sig_TR(N/mm^2)Sig_BR(N/mm^2)Sig_MAX(N/mm^2)Sig_ALW(N/mm^2)1I[1]cLCB19长期FY-MINOK0.762.410.762.410.762.410.760.001I[1]cLCB14短期FY-MINOK0.762.410.762.410.762.410.76-1.922I[2]cLCB19长期MY-MINOK0.722.470.722.470.722.470.720.002I[2]cLCB18短期MY-MINOK0.712.480.712.480.712.480.71-1.923I[3]cLCB19长期MY-MINOK1.002.151.002.151.002.151.000.003I[3]cLCB17短期MY-MINOK0.962.190.962.190.962.190.96-1.924I[4]cLCB19长期MY-MINOK1.333.151.333.151.333.151.330.004I[4]cLCB17短期MY-MINOK1.283.231.283.231.283.231.28-1.925I[5]cLCB17短期MY-MINOK1.733.581.733.581.733.581.73-1.925I[5]cLCB19长期MY-MINOK1.883.361.883.361.883.361.880.006I[6]cLCB19长期MY-MINOK2.353.822.353.822.353.822.350.006I[6]cLCB17短期MY-MINOK2.104.252.104.252.104.252.10-1.927I[7]cLCB18短期MY-MAXOK3.501.943.501.943.501.941.94-1.927I[7]cLCB19长期MY-MINOK2.483.672.483.672.483.672.480.008I[8]cLCB19长期MY-MAXOK5.072.255.072.255.072.252.250.008I[8]cLCB18短期MY-MAXOK5.551.425.561.435.551.421.42-1.929I[9]cLCB19长期MY-MAXOK6.922.656.922.666.922.652.650.009I[9]cLCB18短期MY-MAXOK7.541.627.541.627.541.621.62-1.9210I[10cLCB18短期MY-MAXOK6.531.996.531.996.531.991.99-1.9210I[10cLCB19长期MY-MAXOK5.813.165.813.165.803.163.160.0011I[11cLCB19长期MY-MAXOK5.454.055.454.055.454.054.050.0011I[11cLCB18短期MY-MAXOK6.222.826.222.826.222.822.82-1.9212I[12cLCB19长期MY-MAXOK6.214.906.214.906.204.894.890.0012I[12cLCB18短期MY-MAXOK7.013.627.023.627.013.623.62-1.9213I[13cLCB19长期MY-MAXOK6.184.406.184.406.184.404.400.0013I[13cLCB18短期MY-MAXOK6.933.286.933.286.933.283.28-1.9214I[14cLCB19长期MY-MAXOK6.244.746.244.746.244.734.730.0014I[14cLCB18短期MY-MAXOK6.923.746.933.746.923.743.74-1.9292 15I[15cLCB18短期MY-MAXOK6.734.426.734.426.724.424.42-1.9215I[15cLCB19长期MY-MAXOK6.125.296.125.296.125.295.290.0016I[16cLCB19长期MY-MINOK5.216.695.216.695.216.695.210.0016I[16cLCB17短期MY-MINOK4.547.644.547.644.547.644.54-1.9217I[17cLCB19长期MY-MINOK5.226.835.226.835.226.835.220.0017I[17cLCB17短期MY-MINOK4.577.734.577.734.577.734.57-1.9218I[18cLCB19长期MY-MINOK5.167.475.167.475.167.475.160.0018I[18cLCB17短期MY-MINOK4.538.334.538.334.538.334.53-1.9219I[19cLCB19长期MY-MINOK5.157.995.157.995.157.995.150.0019I[19cLCB17短期MY-MINOK4.538.824.548.824.538.824.53-1.9220I[20cLCB17短期MY-MINOK3.769.003.769.003.768.993.76-1.9220I[20cLCB19长期MY-MINOK4.368.204.368.204.358.204.350.0021I[21cLCB19长期MY-MINOK3.085.283.085.283.085.283.080.0021I[21cLCB17短期MY-MINOK2.585.872.585.872.585.872.58-1.9222I[22cLCB19长期MY-MINOK2.595.832.595.832.595.822.590.0022I[22cLCB17短期MY-MINOK2.076.432.076.432.076.432.07-1.9223I[23cLCB19长期MY-MINOK3.115.473.115.473.105.473.100.0023I[23cLCB17短期MY-MINOK2.626.062.626.062.616.062.61-1.9224I[24cLCB19长期MY-MINOK4.697.854.697.854.697.854.690.0024I[24cLCB17短期MY-MINOK4.098.624.098.624.098.624.09-1.9225I[25cLCB17短期MY-MINOK4.318.494.328.494.318.494.31-1.9225I[25cLCB19长期MY-MINOK4.907.714.907.714.897.714.890.0026I[26cLCB19长期MY-MINOK5.037.685.037.685.037.685.030.0026I[26cLCB17短期MY-MINOK4.478.454.478.454.468.454.46-1.9227I[27cLCB19长期MY-MINOK5.287.435.287.435.287.435.280.0027I[27cLCB17短期MY-MINOK4.738.194.738.194.738.194.73-1.9228I[28cLCB19长期MY-MINOK5.467.205.467.205.467.205.460.0028I[28cLCB17短期MY-MINOK4.947.944.947.944.947.934.94-1.9229I[29cLCB19长期MY-MINOK5.816.805.816.805.816.805.810.0029I[29cLCB17短期MY-MINOK5.307.525.317.525.307.525.30-1.9230I[30cLCB18短期MY-MAXOK7.124.917.124.917.124.914.91-1.9230I[30cLCB19长期MY-MAXOK6.595.666.595.666.595.665.660.0031I[31cLCB19长期MY-MAXOK6.915.036.915.036.915.035.030.0031I[31cLCB18短期MY-MAXOK7.494.187.494.187.494.184.18-1.9232I[32cLCB19长期MY-MAXOK7.535.227.535.227.535.225.220.0032I[32cLCB18短期MY-MAXOK8.164.238.174.238.164.234.23-1.9233I[33cLCB19长期MY-MAXOK7.254.647.254.647.254.644.640.0033I[33cLCB18短期MY-MAXOK7.923.597.923.597.923.593.59-1.9234I[34cLCB19长期MY-MAXOK7.414.707.414.707.414.704.700.0034I[34cLCB18短期MY-MAXOK8.113.588.113.588.113.583.58-1.9235I[35cLCB18短期MY-MAXOK7.323.437.323.437.313.433.43-1.9235I[35cLCB19长期MY-MAXOK6.564.646.564.646.564.644.640.0036I[36cLCB19长期MY-MAXOK5.744.255.744.255.744.254.250.0092 36I[36cLCB18短期MY-MAXOK6.552.936.552.936.552.932.93-1.9237I[37cLCB19长期MY-MAXOK5.744.235.754.235.744.234.230.0037I[37cLCB18短期MY-MAXOK6.562.906.562.916.562.902.90-1.9238I[38cLCB19长期MY-MAXOK5.714.495.714.495.714.484.480.0038I[38cLCB18短期MY-MAXOK6.533.166.533.166.533.163.16-1.9239I[39cLCB18短期MY-MAXOK6.533.166.533.166.523.163.16-1.9239I[39cLCB19长期MY-MAXOK5.714.485.714.485.714.484.480.0040I[40cLCB19长期MY-MAXOK5.754.175.754.175.754.174.170.0040I[40cLCB18短期MY-MAXOK6.572.856.572.856.562.852.85-1.9241I[41cLCB19长期MY-MAXOK5.764.055.764.055.764.054.050.0041I[41cLCB18短期MY-MAXOK6.582.736.582.736.582.732.73-1.9242I[42cLCB19长期MY-MAXOK6.604.106.604.106.594.104.100.0042I[42cLCB18短期MY-MAXOK7.402.807.412.807.402.802.80-1.9243I[43cLCB19长期MY-MAXOK7.093.907.093.907.093.903.900.0043I[43cLCB18短期MY-MAXOK7.842.717.842.717.842.712.71-1.9244I[44cLCB18短期MY-MAXOK7.822.307.822.317.812.302.30-1.9244I[44cLCB19长期MY-MAXOK7.123.417.123.417.113.413.410.0045I[45cLCB19长期MY-MAXOK7.633.487.633.487.623.473.470.0045I[4cLCB18短期MY-MAXOK8.292.448.302.448.292.432.43-1.9246I[46cLCB19长期MY-MAXOK8.013.658.013.658.013.653.650.0046I[46cLCB18短期MY-MAXOK8.652.668.652.668.652.662.66-1.9247I[47cLCB19长期MY-MAXOK7.383.827.383.827.383.823.820.0047I[47cLCB18短期MY-MAXOK7.962.967.972.967.962.962.96-1.9248I[48cLCB19长期MY-MAXOK7.054.357.054.357.054.354.350.0048I[48cLCB18短期MY-MAXOK7.583.597.583.597.583.593.59-1.9249I[49cLCB18短期MY-MAXOK7.084.587.084.587.084.584.58-1.9249I[49cLCB19长期MY-MAXOK6.605.266.605.266.605.265.260.0050I[50cLCB19长期MY-MINOK5.617.205.617.205.617.205.610.0050I[50cLCB17短期MY-MINOK5.097.945.097.945.097.945.09-1.9251I[51cLCB19长期MY-MINOK5.357.715.357.715.357.715.350.0051I[51cLCB17短期MY-MINOK4.818.464.818.474.808.464.80-1.9252I[52cLCB19长期MY-MINOK5.168.165.168.165.168.165.160.0052I[52cLCB17短期MY-MINOK4.608.934.608.934.598.934.59-1.9253I[53cLCB19长期MY-MINOK5.167.985.167.985.167.985.160.0053I[53cLCB17短期MY-MINOK4.588.764.588.764.588.764.58-1.9254I[54cLCB17短期MY-MINOK3.659.213.659.213.649.203.64-1.9254I[54cLCB19长期MY-MINOK4.238.424.238.424.238.424.230.0055I[55cLCB19长期MY-MINOK2.955.442.955.442.955.442.950.0055I[55cLCB17短期MY-MINOK2.466.022.466.022.466.022.46-1.9256I[56cLCB19长期MY-MINOK2.436.032.436.032.436.032.430.0056I[56cLCB17短期MY-MINOK1.916.641.916.641.916.641.91-1.9257I[57cLCB19长期MY-MINOK2.915.692.915.692.915.692.910.0057I[57cLCB17短期MY-MINOK2.426.292.426.292.416.292.41-1.9292 58I[58cLCB17短期MY-MINOK3.858.973.858.973.858.973.85-1.9258I[58cLCB19长期MY-MINOK4.458.194.458.194.458.194.450.0059I[59cLCB19长期MY-MINOK4.547.664.547.674.547.664.540.0059I[59cLCB17短期MY-MINOK3.928.493.928.493.928.493.92-1.9260I[60cLCB19长期MY-MINOK4.656.954.656.954.656.954.650.0060I[60cLCB17短期MY-MINOK4.027.824.027.824.027.824.02-1.9261I[61cLCB17短期MY-MINOK4.167.444.167.444.167.444.16-1.9261I[61cLCB19长期MY-MINOK4.816.534.816.534.816.534.810.0062I[62cLCB19长期MY-MINOK4.776.394.776.394.776.394.770.0062I[62cLCB17短期MY-MINOK4.097.344.097.344.097.344.09-1.9263I[63cLCB18短期MY-MAXOK6.224.126.224.126.224.124.12-1.9263I[63cLCB19长期MY-MINOK4.856.094.856.094.856.094.850.0064I[64cLCB19长期MY-MAXOK5.694.485.694.485.694.484.480.0064I[64cLCB18短期MY-MAXOK6.373.496.373.496.373.493.49-1.9265I[65cLCB19长期MY-MAXOK5.594.145.594.145.594.144.140.0065I[65cLCB18短期MY-MAXOK6.353.026.353.026.353.023.02-1.9266I[66cLCB19长期MY-MAXOK5.594.055.594.055.594.054.050.0066I[66cLCB18短期MY-MAXOK6.402.776.402.776.402.772.77-1.9267I[67cLCB19长期MY-MAXOK5.783.335.783.335.783.333.330.0067I[67cLCB18短期MY-MAXOK6.562.076.562.076.562.072.07-1.9268I[68cLCB18短期MY-MAXOK7.881.697.881.697.881.691.69-1.9268I[68cLCB19长期MY-MAXOK7.152.887.152.887.152.882.880.0069I[69cLCB19长期MY-MAXOK5.561.825.561.825.561.821.820.0069I[69cLCB18短期MY-MAXOK6.190.776.190.776.190.770.77-1.9270I[70cLCB18短期MY-MAXOK3.591.833.591.833.591.831.83-1.9270I[70cLCB19长期MY-MINOK2.463.742.463.742.463.742.460.0071I[71cLCB19长期MY-MINOK2.383.832.383.832.383.832.380.0071I[71cLCB17短期MY-MINOK2.104.322.104.322.104.322.10-1.9272I[72cLCB19长期MY-MINOK2.314.022.314.022.314.022.310.0072I[72cLCB17短期MY-MINOK2.064.442.064.442.064.442.06-1.9273I[73cLCB17短期MY-MINOK1.683.681.683.681.683.681.68-1.9273I[73cLCB19长期MY-MINOK1.833.461.833.461.833.461.830.0074I[74cLCB19长期MY-MINOK1.373.091.373.091.373.091.370.0074I[74cLCB17短期MY-MINOK1.313.171.313.171.313.171.31-1.9275I[75cLCB19长期MY-MINOK0.922.270.922.270.922.270.920.0075I[75cLCB17短期MY-MINOK0.892.310.892.310.892.310.89-1.9276I[76cLCB19长期FX-MINOK0.722.470.722.470.722.470.720.0076I[76cLCB14短期MY-MINOK0.712.480.712.480.712.480.71-1.928.2斜截面抗裂验算斜截面抗裂应对构件斜截面混凝土的主拉应力进行验算，并应符合下列要求：92 1)全预应力混凝土构件，在作用（或荷载）短期效应组合下预制构件现场浇筑（包括预制拼装）构件2)A类和B类预应力混凝土构件，在作用（或荷载）短期效应组合下预制构件现场浇筑（包括预制拼装）构件式中：—在作用（或荷载）短期效应组合下构件抗裂验算边缘混凝土的法向拉应力；—在荷载长期效应组合下构件抗裂验算边缘混凝土的法向拉应力，；—扣除全部预应力损失后的预加力在构件抗裂验算边缘产生的混凝土预压力，按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62-2004第6.1.5条规定计算；—由作用（或荷载）短期效应组合和预加力产生的混凝土主拉应力，按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62-2004第6.3.3条规定计算；—混凝土的抗拉强度标准值，按《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTGD62-2004表3.1.3采用。受弯构件由作用（或荷载）产生的截面抗裂验算边缘混凝土的法向拉应力，应按下列公式计算：式中:—按作用（或荷载）短期效应组合计算的弯矩值；92 —按荷载长期效应组合计算的弯矩值，在组合的活荷载弯矩中，仅考虑汽车、人群等直接作用于构件的荷载产生的弯矩值。注：后张法构件在计算预施应力阶段由构件自重产生的拉应力时，上述两公式中的W0可改用Wn，Wn为构件净截面抗裂验算边缘的弹性抵抗矩。表8.2使用阶段斜截面抗裂性验算单元位置组合名称类型验算Sig_P5(N/mm^2)Sig_P6(N/mm^2)Sig_P7(N/mm^2)Sig_P8(N/mm^2)Sig_P9(N/mm^2)Sig_P10(N/mm^2)Sig_MAX(N/mm^2)Sig_AP(N/mm^2)1I[1]cLCB14FY-MAXOK-0.01-0.01-0.02-0.02-0.02-0.02-0.02-1.372I[2]cLCB18FZ-MINOK-0.22-0.21-0.29-0.28-0.31-0.29-0.31-1.373I[3]cLCB17FX-MAXOK-0.16-0.16-0.20-0.20-0.21-0.21-0.21-1.374I[4]cLCB18FX-MINOK-0.17-0.16-0.25-0.24-0.26-0.25-0.26-1.375I[5]cLCB18FX-MINOK-0.09-0.08-0.11-0.11-0.11-0.10-0.11-1.376I[6]cLCB18FZ-MINOK-0.31-0.30-0.38-0.36-0.36-0.35-0.38-1.377I[7]cLCB18FZ-MINOK-0.28-0.26-0.31-0.30-0.29-0.28-0.31-1.378I[8]cLCB18FX-MAXOK-0.61-0.59-0.56-0.54-0.50-0.48-0.61-1.379I[9]cLCB18FX-MAXOK-1.37-1.35-1.26-1.25-1.12-1.11-1.37-1.3710I[10]cLCB18FX-MAXOK-0.73-0.71-0.70-0.69-0.62-0.61-0.73-1.3711I[11]cLCB18FX-MAXOK-0.36-0.35-0.38-0.37-0.34-0.33-0.38-1.3712I[12]cLCB18FX-MAXOK-0.39-0.39-0.44-0.44-0.39-0.38-0.44-1.3713I[13]cLCB18FX-MAXOK-0.09-0.09-0.11-0.11-0.09-0.09-0.11-1.3714I[14]cLCB18FX-MAXOK-0.06-0.06-0.07-0.07-0.06-0.06-0.07-1.3715I[15]cLCB18FX-MAXOK-0.04-0.04-0.05-0.05-0.04-0.04-0.05-1.3716I[16]cLCB18FX-MAXOK-0.05-0.05-0.07-0.07-0.05-0.05-0.07-1.3717I[17]cLCB18FX-MAXOK-0.03-0.03-0.04-0.04-0.03-0.03-0.04-1.3718I[18]cLCB18FX-MAXOK-0.01-0.01-0.02-0.02-0.01-0.01-0.02-1.3792 19I[19]cLCB18FX-MAXOK-0.01-0.01-0.02-0.02-0.01-0.01-0.02-1.3720I[20]cLCB18FZ-MINOK-0.57-0.57-0.96-0.96-0.81-0.81-0.96-1.3721I[21]cLCB17FZ-MAXOK-0.23-0.23-0.41-0.41-0.36-0.35-0.41-1.3722I[22]cLCB18MX-MAXOK-0.33-0.29-0.58-0.54-0.54-0.49-0.58-1.3723I[23]cLCB17FX-MAXOK-0.31-0.31-0.47-0.47-0.36-0.36-0.47-1.3724I[24]cLCB18FX-MINOK-0.13-0.12-0.25-0.24-0.23-0.22-0.25-1.3725I[25]cLCB18FX-MINOK-0.07-0.07-0.14-0.14-0.13-0.13-0.14-1.3726I[26]cLCB18FX-MINOK-0.05-0.05-0.11-0.10-0.10-0.10-0.11-1.3727I[27]cLCB18FX-MINOK-0.05-0.05-0.10-0.09-0.09-0.09-0.10-1.3728I[28]cLCB18FX-MINOK-0.05-0.05-0.09-0.08-0.08-0.08-0.09-1.3729I[29]cLCB18FX-MINOK-0.08-0.07-0.13-0.13-0.12-0.11-0.13-1.3730I[30]cLCB18FX-MINOK-0.09-0.09-0.14-0.14-0.12-0.12-0.14-1.3731I[31]cLCB18FX-MINOK-0.07-0.07-0.10-0.10-0.09-0.08-0.10-1.3732I[32]cLCB18FX-MINOK-0.18-0.17-0.23-0.22-0.21-0.20-0.23-1.3733I[33]cLCB18FX-MINOK-0.15-0.14-0.18-0.17-0.16-0.15-0.18-1.3734I[34]cLCB18FX-MINOK-0.14-0.13-0.16-0.16-0.15-0.14-0.16-1.3735I[35]cLCB18FX-MINOK-0.07-0.07-0.09-0.08-0.08-0.08-0.09-1.3736I[36]cLCB18FZ-MINOK-0.07-0.06-0.08-0.08-0.07-0.07-0.08-1.3737I[37]cLCB17FZ-MAXOK-0.02-0.02-0.03-0.03-0.03-0.02-0.03-1.3738I[38]cLCB17FZ-MAXOK-0.03-0.03-0.03-0.03-0.03-0.03-0.03-1.3739I[39]cLCB17FZ-MAXOK-0.02-0.02-0.03-0.02-0.03-0.02-0.03-1.3740I[40]cLCB18FZ-MINOK-0.02-0.02-0.02-0.02-0.02-0.02-0.02-1.3741I[41]cLCB17FZ-MAXOK-0.02-0.02-0.03-0.02-0.03-0.02-0.03-1.3742I[42]cLCB18FX-MAXOK-0.09-0.08-0.10-0.09-0.09-0.08-0.10-1.3743I[43]cLCB18FX-MAXOK-0.30-0.29-0.31-0.31-0.28-0.27-0.31-1.3744I[44]cLCB18FX-MAXOK-0.23-0.23-0.23-0.22-0.19-0.19-0.23-1.3745I[45]cLCB18FX-MAXOK-0.13-0.12-0.12-0.11-0.10-0.10-0.13-1.3746I[46]cLCB18FX-MAXOK-0.22-0.22-0.20-0.20-0.17-0.17-0.22-1.3747I[47]cLCB18FX-MAXOK-0.03-0.03-0.03-0.03-0.03-0.03-0.03-1.3748I[48]cLCB18FX-MAXOK-0.02-0.02-0.02-0.02-0.01-0.01-0.02-1.3749I[49]cLCB18FX-MAXOK-0.01-0.01-0.01-0.01-0.01-0.01-0.01-1.3750I[50]cLCB18FX-MAXOK-0.01-0.01-0.02-0.02-0.02-0.02-0.02-1.3751I[51]cLCB18FZ-MINOK-0.01-0.01-0.01-0.01-0.01-0.01-0.01-1.3752I[52]cLCB17FX-MINOK0.000.00-0.010.00-0.010.00-0.01-1.3792 53I[53]cLCB18FX-MAXOK0.000.000.000.000.000.000.00-1.3754I[54]cLCB18FZ-MINOK-0.50-0.50-0.87-0.87-0.75-0.75-0.87-1.3755I[55]cLCB17MX-MINOK-0.27-0.25-0.48-0.44-0.42-0.38-0.48-1.3756I[56]cLCB17MX-MAXOK-0.29-0.26-0.53-0.49-0.51-0.47-0.53-1.3757I[57]cLCB18FX-MAXOK-0.33-0.33-0.51-0.51-0.41-0.41-0.51-1.3758I[58]cLCB17FX-MINOK-0.10-0.09-0.20-0.19-0.19-0.18-0.20-1.3759I[59]cLCB17FX-MINOK-0.07-0.07-0.14-0.13-0.13-0.13-0.14-1.3760I[60]cLCB17FX-MINOK-0.05-0.05-0.10-0.10-0.10-0.09-0.10-1.3761I[61]cLCB17FX-MINOK-0.03-0.03-0.06-0.06-0.05-0.05-0.06-1.3762I[62]cLCB17FX-MINOK-0.02-0.02-0.04-0.04-0.04-0.04-0.04-1.3763I[63]cLCB17FX-MINOK-0.04-0.04-0.08-0.07-0.07-0.07-0.08-1.3764I[64]cLCB17FX-MINOK-0.05-0.05-0.08-0.08-0.07-0.07-0.08-1.3765I[65]cLCB17FX-MINOK-0.03-0.03-0.05-0.05-0.04-0.04-0.05-1.3766I[66]cLCB17FX-MINOK-0.14-0.14-0.20-0.19-0.19-0.19-0.20-1.3767I[67]cLCB17FX-MINOK-0.19-0.18-0.25-0.24-0.23-0.22-0.25-1.3768I[68]cLCB17FX-MINOK-0.19-0.18-0.21-0.20-0.19-0.18-0.21-1.3769I[69]cLCB17FX-MINOK-0.08-0.07-0.08-0.08-0.07-0.07-0.08-1.3770I[70]cLCB18FZ-MAXOK-0.14-0.13-0.15-0.14-0.14-0.13-0.15-1.3771I[71]cLCB18FZ-MAXOK-0.24-0.23-0.28-0.27-0.26-0.25-0.28-1.3772I[72]cLCB18FX-MINOK-0.10-0.09-0.13-0.11-0.12-0.11-0.13-1.3773I[73]cLCB18FX-MINOK-0.21-0.20-0.29-0.27-0.28-0.27-0.29-1.3774I[74]cLCB17FX-MAXOK-0.25-0.25-0.37-0.37-0.39-0.39-0.39-1.3775I[75]cLCB18FZ-MAXOK-0.17-0.16-0.21-0.20-0.21-0.20-0.21-1.3776I[76]cLCB14MZ-MINOK-0.06-0.04-0.08-0.05-0.08-0.06-0.08-1.37通过方案比选、结构尺寸拟定、配筋估算和布置到结构验算，可以确定本设计是安全可靠的。92 致谢首先感谢学校给了我们这次毕业设计的机会，让我们能在即将毕业之际，再次重温和众多同学伙伴一起奋斗的温馨感觉，给我们的大学回忆添上了令人的难忘的一幕。同时在这里，我要着重感谢我的指导老师白青侠和刘来君老师，他们在百忙之余仍定期给我们答疑解惑，解决我们在毕业设计当中遇到的种种困难，在我做毕业设计的每个阶段，从查阅资料到设计草案的确定和修改，中期检查，后期详细设计，装配草图等整个过程中,白老师和刘老师都给予了我悉心的指导，也正是因为有白老师和刘老师的帮助，我的毕业设计才能按期保质完成，为我的大学最后的生活交上一份满意的答卷。毕业设计的这段日子里，我们同一个小组的成员起早贪黑，奔波忙碌在图书馆、绘图室和电脑前，有时候为了赶进度，饭也顾不得吃，只有边画CAD图边吃一些简单的食物聊以充饥。然而这样的日子是充实的而又充满成就感的，当每个人看到自己画出的一幅幅图纸，看到MidasCivil计算软件成功运行计算时，这种充满成就的感动是无法言语的。毕业设计给我们大学最后的生活带来了欢乐，让我们即将分别的日子变得充实而美好。在白老师和刘老师的指导下，通过为期八周的毕业设计，我熟悉了桥梁结构的设计分析流程，了解了桥梁结构的设计理念和施工方法，掌握了桥梁结构的结构受力和构造特征。通过设计实践，我接触到更多专业前沿的知识，开拓了眼界，增加了专业知识储备。结构设计软件的使用使我增强了动手实践的能力和结构分析计算能力。在设计过程中，我将课堂中所学的知识运用到设计实践中去，通过亲身实践，将所学的知识融会贯通，初步形成了自己的设计理念，提高了专业素养。这次毕业设计，我达到了塑造和树立专业理念、串联本科期间所学专业知识、熟练运用桥梁结构计算软件的目的，并为自己以后的学习和工作打下坚实的理论和实践基础。92 在这里，我再次感谢对我进行毕业设计指导的白青侠和刘来君老师,并感谢公路学院的各级领导对我们桥梁学子的巨大支持和帮助。参考文献【1】中华人民共和国交通部标准《公路桥涵设计通用规范（JTGD60-2004）》北京：人民交通出版社。【2】中华人民共和国交通部标准《公路钢筋混凝土及预应力混凝土桥涵设计规范（JTGD62-2004）》北京：人民交通出版社。【3】范立础主编《桥梁工程》（上册）北京：人民交通出版社，2001【4】叶见曙主编《结构设计原理》北京：人民交通出版社，1997【5】张继尧主编《悬臂浇筑预应力混凝土连续梁桥》北京：人民交通出版社，2004【6】邵旭东编著《桥梁设计与计算》北京人民交通出版社，2007【7】朱新实编著《预应力技术及材料设备》北京人民交通出版社，2005【8】陈忠延主编《土木工程专业毕业设计指南（桥梁工程分册）》北京中国水利水电出版社，200092 附录外文资料翻译英文原文ThebridgecrackproducedthereasontosimplyanalyseInrecentyears,thetrafficcapitalconstructionofourprovincegetsswiftandviolentdevelopment,allpartshavebuiltalargenumberofconcretebridges.Inthecourseofbuildingandusinginthebridge,relevanttoinfluenceprojectqualityleadofcommonoccurrencereportthatbridgecollapseevenbecausethecrackappearsTheconcretecanbesaidto"oftenhaveillnesscomingon"whilefracturingand"frequently-occurringdisease",oftenperplexbridgeengineersandtechnicians.Infact,iftakecertaindesignandconstructionmeasure,alotofcrackscanbeovercomeandcontrolled.Forstrengthenunderstandingofconcretebridgecrackfurther,isitpreventprojectfromendangerlargercracktotryone"sbest,thistextmakeanmoreoverallanalysis,summarytoconcretekindandreasonofproduction,bridgeofcrackasmuchaspossible,inordertodesign,constructandfindoutthefeasiblemethodwhichcontrolthecrack,gettheresultoftakingprecautionsagainstYuWeiRan.Concretebridgecrackkind,origincauseofformationInfact,theorigincauseofformationoftheconcretestructurecrackiscomplicatedandvarious,evenmanykindsoffactorsinfluenceeachother,buteverycrackhasitsoneorseveralkindsofmainreasonsproduced.Thekindoftheconcretebridgecrack,onitsreasontoproduce,canroughly92 divideseveralkindsasfollows:(1)loadthecrackcausedConcreteinroutinequietIsitloadtomoveandcrackthatproduceclaimtoloadthecrackunderthetimesofstressbridge,summinguphasdirectstresscracks,twokindsstresscrackoncesmainly.Directstresscrackrefertooutsideloaddirectcrackthatstressproducethatcause.Thereasonwhythecrackproducesisasfollows,1,Designthestageofcalculating,doesnotcalculateorleaksandcalculatespartlywhilecalculatinginstructure;Calculatethemodelisunreasonable;Thestructureissupposedandaccordedwithbystrengthactuallybystrength;Loadandcalculateorleakandcalculatefew;Internalforceandmatchingthemistakeincomputationofmuscle;Safetycoefficientofstructureisnotenough.Donotconsiderthepossibilitythatconstructatthetimeofthestructuraldesign;Itisinsufficienttodesignthesection;Itissimplylittleandassigningthemistakeforreinforcingbartosetup;Structurerigidityisinsufficient;Constructanddealwithimproperly;Thedesigndrawingcannotbeexplainedclearlyetc..2,Constructionstage,doesnotpileupandconstructthemachines,materiallimiting;Isitprefabricatestructurestructurereceivestrengthcharacteristic,standup,isithang,transport,installtogetupatwilltounderstand;Constructnotaccordingtothedesigndrawing,altertheconstructionorderofthestructurewithoutauthorization,changethestructureandreceivethestrengthmode;Donotdothetiredintensitycheckingcomputationsundermachinevibrationandwaittothestructure.3,Usingstage,theheavy-dutyvehiclewhichgoesbeyondthedesignloadpassesthebridge;Receivethecontact,strikingofthevehicle,shipping;Strongwind,heavysnow,earthquakehappen,explodeetc..Stresscrackoncemeansthestressofsecondarycausedbyloadingoutsideproducesthecrack.Thereasonwhythecrackproducesisasfollows,1,Indesignoutsideloadfunction,becauseactualworkingstateandroutine,structureofthingcalculatehavediscrepancyorisitconsidertocalculate,thuscausestressoncetocausethestructuretofractureinsomeposition.Twoisitjoinbridgearchfootisitisitassign"X"shapereinforcingbar,cutdownthisplaceway,sectionofsizedesignandcutwithscissorsatthesametimetoadoptoftentodesigntocutwithscissors,theorycalculateplacethiscanstorecurvedsquarein,butrealityshouldisitcanresistcurvedstilltocutwithscissors,sothatpresentthecrackand92 causethereinforcingbarcorrosion.2,Bridgestructureisitdigtrough,turnonhole,setupoxleg,etc.toneedoften,difficulttouseaaccurateonediagrammatictoisitisitcalculatetoimitatetogoonincalculatinginroutine,setupandreceivethestrengthreinforcingbaringeneralfoundationexperience.Studieshaveshown,afterbeingdugtheholebythestrengthcomponent,itwillproducethediffractionphenomenonthatstrengthflows,intensiveneartheholeinautensil,producedtheenormousstresstoconcentrate.Inlongtostepprestressingforceofthecontinuousroofbeam,oftenblockthesteelbunchaccordingtotheneedsofsectioninternalforceinstepping,setuptheanchorhead,butcanoftenseethecrackintheanchorfirmsectionadjacentplace.Soifdealwithimproper,incornerorcomponentformsuddenchangeoffice,blockplacetobeeasytoappearcrackstrengthreinforcingbarofstructurethe.Intheactualproject,stresscrackonceproducedthemostcommonreasonwhichloadsthecrack.Stresscrackoncebelongtoonemorepieceofnatureofdrawing,splittingoff,shearing.Stresscrackonceisloadedandcaused,onlyseldomcalculateaccordingtotheroutinetoo,butwithmoderntocalculateconstantperfectionofmeans,timesofstresscracktocanaccomplishreasonablecheckingcomputationstoo.Forexampletosuchstresses2timesofproducingasprestressingforce,creeping,etc.,department"sfiniteelementprocedurecalculateslevelspolecorrectlynow,butmoredifficult40yearsago.Inthedesign,shouldpayattentiontoavoidingstructuresuddenchange(orsectionsuddenchange),whenitisunabletoavoid,shoulddopartdealwith,cornerforinstance,makeroundhorn,suddenchangeofficemakeintothegradationzonetransition,isitisitmixmuscletoconstructtostrengthenatthesametime,cornermixagainobliquetoreinforcingbar,astolargeholeinautensilcansetupprotectingintheperimeteratthetermsofhavinganglesteel.Loadthecrackcharacteristicinaccordancewithloadingdifferentlyandpresentingdifferentcharacteristicsdifferently.Thecrackappearpersonwhodrawmore,thecuttingareaortheseriouspositionofvibration.Mustpointout,isitgetupcoverorhavealongkeepintoshortcrackofdirectiontoappearpersonwhopress,oftenthestructurereachesthesignofbearingtheweightofstrengthlimit,itisanomenthatthestructureisdestroyed,itsreasonisoftenthatsectionalsizeispartialandsmall.Receivethestrengthwaydifferentlyaccordingtothestructure,thecrackcharacteristicproducedisasfollows:1,92 Thecentreisdrawn.Thecrackrunsthroughthecomponentcrosssection,theintervalisequalonthewhole,andisperpendiculartoreceivingthestrengthdirection.Whileadoptingthewhorlreinforcingbar,lieinthesecond-classcracknearthereinforcingbarbetweenthecracks.2,Thecentreispressed.Itisparallelontheshortanddenseparallelcrackwhichreceivethestrengthdirectiontoappearalongthecomponent.3,Receivecurved.Mostnearthelargesectionfromborderisitappearanddrawintodirectionverticalcracktobeginpersonwhodrawcurvedsquare,anddeveloptowardneutralizationaxlegradually.Whileadoptingthewhorlreinforcingbar,canseeshortersecond-classcrackamongthecracks.Whenthestructurematchesmusclesless,therearefewbutwidecracks,fragilitydestructionmaytakeplaceinthestructure4,Pressedbigandpartial.Heavytopressandmixpersonwhodrawmusclealessonelighttopigeonholeintothecomponentwhilebeingpartialwhilebeingpartial,similartoreceivingthecurvedcomponent.5,Pressedsmallandpartial.Smalltopressandmixpersonwhodrawmuscleamoreoneheavytopigeonholeintothecomponentwhilebeingpartialwhilebeingpartial,similartothecentreandpressedthecomponent.6,Cut.Pressobliqulywhenthehoopmuscleistoodenseanddestroy,theobliquecrackwhichisgreaterthan45??directionappearsalongthebellyofroofbeamend;Isitisitisitdestroytopresstocuttohappenwhenthehoopmuscleisproper,underpartisitinvite45??directionparallelobliquecrackeachothertoappearalongroofbeamend.7,Sprained.Componentonesidebellyappearmanydirectionobliquecrack,45??oftreaty,first,andtolaunchwithspiraldirectionbeingadjoint.8,Washedandcut.4sideisitinvite45??directioninclinedplanedrawandsplittotakeplacealongcolumncapboard,formthetangentplaneofwashing.9,Someandispressed.Sometoappearpersonwhopressdirectionroughlyparallellargeshortcrackswithpressure.(2)crackcausedintemperaturechangeTheconcretehasnatureofexpandingwithheatandcontractwithcold,lookonastheexternalenvironmentconditionorthestructuretemperaturechanges,concretetakeplaceoutofshape,ifoutofshapetorestrainfrom,producethestressinthestructure,producethetemperaturecrackpromptlywhenexceedingconcretetensilestrengthinstress.Insomebeingheavytostepfoot-pathamongthebridge,temperaturestresscan92 isitgobeyondlivingyearstresseventoreach.Thetemperaturecrackdistinguishesthemaincharacteristicofothercrackswillbevariedwithtemperatureandexpandedorclosedup.Themainfactorisasfollows,tocausetemperatureandchange1,Annualdifferenceintemperature.Temperatureischangingconstantlyinfourseasonsinoneyear,butchangerelativelyslowly,theimpactonstructureofthebridgeismainlytheverticaldisplacementwhichcausesthebridge,canpropupseatmoveorsetupflexiblemound,etc.nottoconstructmeasurecoordinate,throughbridgefloorexpansionjointgenerally,cancausetemperaturecrackonlywhenthedisplacementofthestructureislimited,forexamplearchedbridge,justbridgeetc.TheannualdifferenceintemperatureofourcountrygenerallychangestherangewiththeconductoftheaveragetemperatureinthemoonofJanuaryandJuly.Consideringthecreepcharacteristicoftheconcrete,theelasticmouldamountofconcreteshouldbeconsideredrollingoverandreducingwhentheinternalforceoftheannualdifferenceintemperatureiscalculated.2,Rizhao.Afterbeingtannedbythesunbythesuntothesideofbridgepanel,thegirderorthepier,temperatureisobviouslyhigherthanotherposition,thetemperaturegradientispresentedanddistributedbythelineshape.Becauseofrestrainoneselffunction,causepartdrawstresstoberelativelyheavy,thecrackappears.Rizhaoandfollowingtoisitcausestructurecommonreasonmost,temperatureofcracktolowerthetemperaturesuddenly3,Lowerthetemperaturesuddenly.Fallheavyrain,coldairattack,sunset,etc.cancausestructuresurfacetemperaturesuddenlydroppedsuddenly,butbecauseinsidetemperaturechangerelativelyslowproducingtemperaturegradient.Rizhaoandlowerthetemperatureinternalforcecanadoptdesignspecificationorconsultrealbridgematerialsgoonwhencalculatingsuddenly,concreteelasticmouldamountdoesnotconsiderconvertingintoandreducing4,Heatofhydration.Appearinthecourseofconstructing,thelargevolumeconcrete(thicknessexceeds2.0),afterbuildingbecausecementwatersendoutheat,causeinsideverymuchhightemperature,theinternalandexternaldifferenceintemperatureistoolarge,causethesurfacetoappearinthecrack.Shouldaccordingtoactualconditionsinconstructing,isitchooseheatofhydrationlowcementvarietytotryone"sbest,limitcementunit"sconsumption,reducetheaggregateandenterthetemperatureofthemould,reducetheinternalandexternaldifferencein92 temperature,andlowerthetemperatureslowly,canadoptthecirculationcoolingsystemtocarryontheinsidetodispeltheheatincaseofnecessity,oradoptthethinlayerandbuilditinsuccessioninordertoacceleratedispellingtheheat.5,Theconstructionmeasureisimproperatthetimeofsteammaintenanceorthewinterconstruction,theconcreteissuddenandcoldandsuddenandhot,internalandexternaltemperatureisuneven,apttoappearinthecrack.6,PrefabricateTroofbeamhorizontalbafflewhentheinstallation,propupseatburystencilplatewithtransferflatstencilplatewhenweldinginadvance,ifweldmeasuretobeimproper,ironpiecesofnearbyconcreteeasytoisitfracturetoburn.Adoptelectricheatpiecedrawlawpiecedrawprestressingforceatthecomponent,prestressingforcesteeltemperaturecanriseto350degreesCentigrade,theconcretecomponentisapttofracture.Experimentalstudyindicates,arecausedtheintensityofconcretethatthehightemperatureburnstoobviouslyreducewithrisingoftemperaturebysuchreasonsasthefire,etc.,glueingformingthedeclinethereuponofstrengthofreinforcingbarandconcrete,tensilestrengthdropby50%afterconcretetemperaturereaches300degreesCentigrade,compressionstrengthdropsby60%,glueingthestrengthofformingtodropby80%ofonlyroundreinforcingbarandconcrete;Becauseheat,concretebodydissociateinkevaporateandcanproduceandshrinksharplyinalargeamount(3)shrinkthecrackcausedIntheactualproject,itisthemostcommonbecauseconcreteshrinksthecrackcaused.Shrinkkindinconcrete,plasticityshrinkisititshrinks(isitcontracttodo)tobethemainreasonthatthevolumeofconcreteoutofshapehappenstoshrink,shrinkspontaneouslyinadditionandthecharshrink.Plasticityshrink.About4hoursafteritisbuiltthatinthecourseofconstructing,concretehappens,thecementwaterresponseisfierceatthismoment,thestrandtakesshapegradually,secretewaterandmoisturetoevaporatesharply,theconcretedesiccatesandshrinks,itisatthesametimeconductoneselfwithdignitynotsinkingbecauseaggregate,sowhenhardenconcreteyet,itcallplasticityshrink.Theplasticityshrinkproducingamountgradeisverybig,canbeuptoabout1%.Ifstoppedbythereinforcingbarwhiletheaggregatesinks,formthecrackalongthereinforcingbardirection.Ifweb,roofbeamofTandroofbeamofcaseand92 carrybaseplatehandoverofficeincomponentverticaltobecomesectionalplace,becausesinktooreallytosuperficialobeyingthewebdirectioncrackwillhappenevenlybeforehardenning.Forreducingconcreteplasticityshrink,itshouldcontrolbywaterdustwhenbeingconstructthan,lastlong-timemixing,unloadingshouldnottooquick,isitisittakecloselyknittosmashtoshake,verticaltobecomesectionalplaceshoulddividelayerbuild.Shrinkandshrink(doandcontract).Aftertheconcreteisformedhard,asthetoplayermoistureisevaporatedprogressively,thehumidityisreducedprogressively,thevolumeofconcreteisreduced,iscalledandshrunktoshrink(doandcontract).Becauseconcretetoplayermoisturelosssoon,itisslowforinsidetolose,producesurfaceshrinkheavy,insideshrinkalightoneeventoshrink,itisoutofshapetorestrainfrombytheinsideconcreteforsurfacetoshrink,causethesurfaceconcretetobearpullingforce,whenthesurfaceconcretebearspullingforcetoexceeditstensilestrength,produceandshrinkthecrack.Theconcretehardensafter-contractiontojustshrinkandshrinkmainly.Suchasmixmusclerateheavycomponent(exceed3%),betweenreinforcingbarandmoreobviousrestraintsrelativelythatconcreteshrink,theconcretesurfaceisapttoappearinthefullofcrackscrackle.Shrinkspontaneously.Spontaneoustoitshrinkstobeconcreteinthecourseofhardenning,cementandwatertakeplaceinkreact,theshrinkwithhavenothingtodobyexternalhumidity,andcanpositive(whethershrink,suchasordinaryportlandcementconcrete),cannegativetoo(whetherexpand,suchasconcrete,concreteofslagcementandcementofflyash).Thecharshrinks.Betweencarbondioxideandhyrateofcementofatmospheretakeplaceoutofshapeshrinkthatchemicalreactioncause.Thecharshrinksandcouldhappenonlyabout50%ofhumidity,andacceleratewithincreaseofthedensityofthecarbondioxide.Thecharshrinksandseldomcalculates.Thecharacteristicthattheconcreteshrinksthecrackisthatthemajoritybelongstothesurfacecrack,thecrackisrelativelydetailedinwidth,andcriss-cross,becomethefullofcracksform,theformdoesnothaveanylaw.Studieshaveshown,influenceconcreteshrinkmainfactorofcrackasfollows,1,Varietyofcement,gradeandconsumption.Slagcement,quick-hardeningcement,low-heatcementconcretecontractivityarerelativelyhigh,ordinarycement,volcanicashcement,aluminacementconcretecontractivityarerelativelylow.Cementgradelowinaddition,unitvolume92 consumptionheavyrubingdetaileddegreeheavy,thentheconcreteshrinksthemoregreatly,andshrinktimeisthelonger.Forexample,inordertoimprovetheintensityoftheconcrete,oftenadoptandincreasethecementconsumptionmethodbyforcewhileconstructing,theresultshrinksthestresstoobviouslystrengthen.2,Varietyofaggregate.Suchabsorbingwaterratesasthequartz,limestone,cloudrock,granite,feldspar,etc.aresmaller,contractivityisrelativelylowintheaggregate;Andsuchabsorbingwaterratesasthesandstone,slate,angleamphibolite,etc.aregreater,contractivityisrelativelyhigh.Aggregategrainsoffoot-pathheavytoshrinklightinaddition,watercontentbigtoshrinkthelarger.3,Watergraythan.Theheavierwaterconsumptionis,thehigherwateranddustare,theconcreteshrinksthemoregreatly.4,Mixthepharmaceuticaloutside.Itisthebettertomixpharmaceuticalwater-retainingpropertyoutside,thentheconcreteshrinksthesmaller.5,Maintainthemethod.Waterthatgoodmaintenancecanacceleratetheconcretereacts,obtaintheintensityofhigherconcrete.Keephumidityhigh,lowmaintainingtimetobethelongertemperaturewhenmaintaining,thentheconcreteshrinksthesmaller.Steammaintainwaythanmaintainwayconcreteisittakelighttoshrinknaturall.6,Externalenvironment.Thehumidityislittle,theairdrying,temperaturearehigh,thewindspeedislargeintheatmosphere,thentheconcretemoistureisevaporatedfast,theconcreteshrinksthefaster.7,Shakeandsmashthewayandtime.Machineryshakewayofsmashingthanmakefirmbyrammingortampingwayconcretecontractivitytakelittlebyhand.Shakingshoulddetermineaccordingtomechanicalperformancetosmashtime,aregenerallysuitablefor55s/time.Itistooshort,shakeandcannotsmashcloselyknit,itisinsufficientornoteveninintensitytoformtheconcrete;Itistoolong,causeanddividestorey,thickaggregatesinkstothegroundfloor,theupperstratathatthedetailedaggregatestays,theintensityisnoteven,theupperstrataincidentshrinkthecrack.Andshrinkthecrackcausedtotemperature,worthyofconstructingthereinforcingbaragainingcanobviouslyimprovetheresistingthesplittingofconcrete,structureofespeciallythinwall(thick200cmofwall).Mixmuscleshouldisitadoptlightdiameterreinforcingbar(8|?construct14|?)tohavepriority,littleintervalassign(whether@10construct@15cm)onconstructing,thewholesectionisitmixmuscletoberateunsuitabletobelowerthan92 0toconstruct.3%,cangenerallyadopt0.3%~0.5%.(4)crackthatcausesoutofshapeofplinthofthegroundBecausefoundationverticaltoeventosubsideorhorizontaldirectiondisplacement,makethestructureproducetheadditionalstress,gobeyondresistingtheabilityofdrawingofconcretestructure,causethestructuretofracture.Theevenmainreasonthatsubsideofthefoundationisasfollows,1,Reconnoitrestheprecisionandisnotenoughfor,testthematerialsinaccuratlyingeology.Designing,constructingwithoutfullygraspingthegeologicalsituation,thisisthemainreasonthatcausethegroundnottosubsideevenly.Suchashillsareaorbridge,districtofmountainridge,,holeintervaltobetoofarwhenreconnoitring,andgroundriseandfallbigtherock,reconnoitringthereportcan"tfullyreflecttherealgeologicalsituation.2,Thegeologicaldifferenceofthegroundistoolarge.Buildingitinthebridgeofthevalleyoftheditchofmountainarea,geologyofthestreamplaceandplaceonthehillsidechangelarger,eventhereareweakgroundsinthestream,becausethesoilofthegrounddoesnotcausesanddoesnotsubsideevenlywiththecompressing.3,Thestructureloadsthedifferencetoobig.Undertheunanimousterms,wheneveryfoundationtooheavytoloaddifferenceingeologicalsituation,maycauseevenlytosubside,forexamplehightofilloutsoilcaseshapeinthemiddlepartoftheculvertthantoisittakeheavytoloadbothsides,tosubsidesoonheavythanbothsidesmiddlepart,caseisitmightfracturetocontain4,Thedifferenceofbasictypeofstructureisgreat.Uniteitinthebridgethesamly,mixanduseanddoesnotexpandthefoundationandafoundationwiththefoundation,oradoptafoundationwhenafoot-pathoralongdifferenceisgreatatthesametime,oradoptthefoundationofexpandingwhenbasiselevationiswidelydifferentatthesametime,maycausethegroundnottosubsideevenlytoo5,Foundationbuiltbystages.Inthenewly-builtbridgenearthefoundationoforiginalbridge,ifthehalfabridgeaboutexpresswaybuiltbystages,thenewly-builtbridgeloadsorthefoundationcausesthesoilofthegroundtoconsolidateagainwhiledealingwith,maycauseandsubsidethefoundationoforiginalbridgegreatly6,Thegroundisfrozenbloatedly.Thegroundsoilofhighermoisturecontentontermsthatlowerthanzerodegreeexpandsbecauseofbeingicy;Oncetemperaturegoesup,thefrozensoilismelted,thesettingofground.Sothegroundisicy92 ormeltscausesanddoesnotsubsideevenly.7,Bridgefoundationputonbody,cavewithstalactitesandstalagmites,activityfault,etc.ofcomingdownatthebadgeology,maycauseanddoesnotsubsideevenly.8,Afterthebridgeisbuiltup,theconditionchangeoforiginalground.Aftermostnaturalgroundsandartificialgroundsaresoakedwithwater,especiallyusuallyfilloutsuchsoilofspecialgroundasthesoil,loess,expandingintheland,etc.,soilbodyintensitymeetwaterdrop,compressoutofshapetostrengthen.Inthesoftsoilground,seasoncausesthewatertabletodroptodrawwateroraridartificially,thegroundsoillayerconsolidatesandsinksagain,reducethebuoyancyonthefoundationatthesametime,shoulderingtheobstructionofrubingtoincrease,thefoundationiscarriedonone"sshoulderorbackandstrengthened.Somebridgefoundationisitputtooshallowtobury,erode,isitdigtowashflood,thefoundationmightbemoved.Groundloadchangeofterms,bridgenearbyisitisitabolishsquare,grit,etc.inalargeamounttoputtopilewithcavein,landslide,etc.reasonforinstance,itisoutofshapethatthebridgelocationrangesoillayermaybecompressedagain.So,theconditionoforiginalgroundchangewhileusingmaycauseanddoesnotsubsideevenlyProducethestructurethingofhorizontalthrusttoarchedbridge,etc.,itisthemainreasonthathorizontaldisplacementcrackemergestodestroytheoriginalgeologicalconditionwhentothatitisunreasonabletograspincompletely,designandconstructinthegeologicalsituation.92 中文翻译桥梁裂缝产生原因浅析近年来，我省交通基础建设得到迅猛发展，各地建立了大量的混凝土桥梁。在桥梁建造和使用过程中，出现了大量有关因出现裂缝而影响工程质量甚至导桥梁垮塌的报道。混凝土开裂可以说是“常发病”和“多发病”，经常困扰着桥梁工程技术人员。其实，如果采取一定的设计和施工措施，很多裂缝是可以克服和控制的。为了进一步加强对混凝土桥梁裂缝的认识，尽量避免工程中出现危害较大的裂缝，本文对混凝土桥梁裂缝的种类和产生的原因作较全面的分析、总结，以方便设计、施工找出控制裂缝的可行办法，达到预防的作用。混凝土桥梁裂缝种类和形成原因复杂而繁多，甚至多种因素相互影响，但每一条裂缝均有其产生的一种或几种主要原因。这种混凝土桥梁裂缝，就其产生的原因，大致可划分如下几种：一、荷载引起的裂缝混凝土桥梁在常规静、动荷载及次应力下产生的裂缝称荷载裂缝，归纳起来主要有直接应力裂缝、次应力裂缝两种。直接应力裂缝是指外荷载引起的直接应力产生的裂缝。裂缝产生的原因有：(1)设计计算阶段，结构计算时不计算或部分漏算；计算模型不合理；结构受力假设与实际受力不符；荷载少算或漏算；内力与配筋计算错误；结构安全系数不够。结构设计时不考虑施工的可能性；设计断面不足；钢筋设置偏少或布置错误；结构刚度不足；构造处理不当；设计图纸交代不清等。(2)施工阶段，不加限制地堆放施工机具、材料；不了解预制结构结构受力特点，随意翻身、起吊、运输、安装；不按设计图纸施工，擅自更改结构施工顺序，改变结构受力模式；不对结构做机器振动下的疲劳强度验算等。(3)使用阶段，超出设计载荷的重型车辆过桥；受车辆、船舶的接触、撞击；发生大风、大雪、地震、爆炸等。次应力裂缝是指由外荷载引起的次生应力产生裂缝。裂缝产生的原因有：92 (1)在设计外荷载作用下，由于结构物的实际工作状态同常规计算有出入或计算不考虑，从而在某些部位引起次应力导致结构开裂。例如两铰拱桥拱脚设计时常采用布置“X”形钢筋、同时削减该处断面尺寸的办法设计铰，理论计算该处不会存在弯矩，但实际该铰仍然能够抗弯，以至出现裂缝而导致钢筋锈蚀。(2)桥梁结构中经常需要凿槽、开洞、设置牛腿等，在常规计算中难以用准确的图式进行模拟计算，一般根据经验设置受力钢筋。研究表明，受力构件挖孔后，力流将产生绕射现象，在孔洞附近密集，产生巨大的应力集中。在长跨预应力连续梁中，经常在跨内根据截面内力需要截断钢束，设置锚头，而在锚固断面附近经常可以看到裂缝。因此，若处理不当，在这些结构的转角处或构件形状突变处、受力钢筋截断处容易出现裂缝。实际工程中，次应力裂缝是产生荷载裂缝的最常见原因。次应力裂缝多属张拉、劈裂、剪切性质。次应力裂缝也是由荷载引起，仅是按常规一般不计算，但随着现代计算手段的不断完善，次应力裂缝也是可以做到合理验算的。例如现在对预应力、徐变等产生的二次应力，不少平面杆系有限元程序均可正确计算，但在40年前却比较困难。在设计上，应注意避免结构突变（或断面突变），当不能回避时，应做局部处理，如转角处做圆角，突变处做成渐变过渡，同时加强构造配筋，转角处增配斜向钢筋，对于较大孔洞有条件时可在周边设置护边角钢。荷载裂缝特征依荷载不同而异呈现不同的特点。这类裂缝多出现在受拉区、受剪区或振动严重部位。但必须指出，如果受压区出现起皮或有沿受压方向的短裂缝，往往是结构达到承载力极限的标志，是结构破坏的前兆，其原因往往是截面尺寸偏小。根据结构不同受力方式，产生的裂缝特征如下：(1)中心受拉。裂缝贯穿构件横截面，间距大体相等，且垂直于受力方向。采用螺纹钢筋时，裂缝之间出现位于钢筋附近的次裂缝。(2)中心受压。沿构件出现平行于受力方向的短而密的平行裂缝。(3)受弯。弯矩最大截面附近从受拉区边沿开始出现与受拉方向垂直的裂缝，并逐渐向中和轴方向发展。采用螺纹钢筋时，裂缝间可见较短的次裂缝。当结构配筋较少时，裂缝少而宽，结构可能发生脆性破坏。(4)大偏心受压。大偏心受压和受拉区配筋较少的小偏心受压构件，类似于受弯构件。(5)小偏心受压。小偏心受压和受拉区配筋较多的大偏心受压构件，类似于中心受压构件。92 (6)受剪。当箍筋太密时发生斜压破坏，沿梁端腹部出现大于45度方向的斜裂缝；当箍筋适当时发生剪压破坏，沿梁端中下部出现约45度方向相互平行的斜裂缝。(7)受扭。构件一侧腹部先出现多条约45度方向斜裂缝，并向相邻面以螺旋方向展开。(8)受冲切。沿柱头板内四侧发生约45度方向斜面拉裂，形成冲切面。(9)局部受压。在局部受压区出现与压力方向大致平行的多条短裂缝。二、温度变化引起的裂缝混凝土具有热胀冷缩性质，当外部环境或结构内部温度发生变化，混凝土将发生变形，若变形遭到约束，则在结构内将产生应力，当应力超过混凝土抗拉强度时即产生温度裂缝。在某些大跨径桥梁中，温度应力可以达到甚至超出活载应力。温度裂缝区别其它裂缝最主要特征是将随温度变化而变化。引起温度变化主要因素有：(1)年温差。一年中四季温度不断变化，但变化相对缓慢，对桥梁结构的影响主要是导致桥梁的纵向位移，一般可通过桥面伸缩缝、支座位移或设置柔性墩等构造措施相协调，只有结构的位移受到限制时才会引起温度裂缝，例如拱桥、刚架桥等。我国年温差一般以一月和七月月平均温度的作为变化幅度。考虑到混凝土的蠕变特性，年温差内力计算时混凝土弹性模量应考虑折减。(2)日照。桥面板、主梁或桥墩侧面受太阳曝晒后，温度明显高于其它部位，温度梯度呈非线形分布。由于受到自身约束作用，导致局部拉应力较大，出现裂缝。日照和下述骤然降温是导致结构温度裂缝的最常见原因。(3)骤然降温。突降大雨、冷空气侵袭、日落等可导致结构外表面温度突然下降，但因内部温度变化相对较慢而产生温度梯度。日照和骤然降温内力计算时可采用设计规范或参考实桥资料进行，混凝土弹性模量不考虑折减。(4)水化热。出现在施工过程中，大体积混凝土（厚度超过2.0米）浇筑之后由于水泥水化放热，致使内部温度很高，内外温差太大，致使表面出现裂缝。施工中应根据实际情况，尽量选择水化热低的水泥品种，限制水泥单位用量，减少骨料入模温度，降低内外温差，并缓慢降温，必要时可采用循环冷却系统进行内部散热，或采用薄层连续浇筑以加快散热。(5)蒸汽养护或冬季施工时施工措施不当，混凝土骤冷骤热，内外温度不均，易出现裂缝。92 (6)预制T梁之间横隔板安装时，支座预埋钢板与调平钢板焊接时，若焊接措施不当，铁件附近混凝土容易烧伤开裂。试验研究表明，由火灾等原因引起高温烧伤的混凝土强度随温度的升高而明显降低，钢筋与混凝土的粘结力随之下降，混凝土温度达到300℃后抗拉强度下降50%，抗压强度下降60%，光圆钢筋与混凝土的粘结力下降80%；由于受热，混凝土体内游离水大量蒸发也可产生急剧收缩。三、收缩引起的裂缝在实际工程中，混凝土因收缩所引起的裂缝是最常见的。在混凝土收缩种类中，塑性收缩和缩水收缩（干缩）是发生混凝土体积变形的主要原因，另外还有自生收缩和炭化收缩。塑性收缩:发生在施工过程中、混凝土浇筑后4～5小时左右，此时水泥水化反应激烈，分子链逐渐形成，出现泌水和水分急剧蒸发，混凝土失水收缩，同时骨料因自重下沉，因此时混凝土尚未硬化，称为塑性收缩。塑性收缩所产生量级很大，可达1%左右。在骨料下沉过程中若受到钢筋阻挡，便形成沿钢筋方向的裂缝。在构件竖向变截面处如T梁、箱梁腹板与顶底板交接处，因硬化前沉实不均匀将发生表面的顺腹板方向裂缝。为减小混凝土塑性收缩，施工时应控制水灰比，避免过长时间的搅拌，下料不宜太快，振捣要密实，竖向变截面处宜分层浇筑。缩水收缩（干缩）:混凝土结硬以后，随着表层水分逐步蒸发，湿度逐步降低，混凝土体积减小，称为缩水收缩（干缩）。因混凝土表层水分损失快，内部损失慢，因此产生表面收缩大、内部收缩小的不均匀收缩，表面收缩变形受到内部混凝土的约束，致使表面混凝土承受拉力，当表面混凝土承受拉力超过其抗拉强度时，便产生收缩裂缝。混凝土硬化后收缩主要就是缩水收缩。如配筋率较大的构件（超过3%），钢筋对混凝土收缩的约束比较明显，混凝土表面容易出现龟裂裂纹。自生收缩:自生收缩是混凝土在硬化过程中，水泥与水发生水化反应，这种收缩与外界湿度无关，且可以是正的（即收缩，如普通硅酸盐水泥混凝土），也可以是负的（即膨胀，如矿渣水泥混凝土与粉煤灰水泥混凝土）。炭化收缩:大气中的二氧化碳与水泥的水化物发生化学反应引起的收缩变形。炭化收缩只有在湿度50%左右才能发生，且随二氧化碳的浓度的增加而加快。炭化收缩一般不做计算。92 混凝土收缩裂缝的特点是大部分属表面裂缝，裂缝宽度较细，且纵横交错，成龟裂状，形状没有任何规律。研究表明，影响混凝土收缩裂缝的主要因素有：(1)水泥品种、标号及用量。矿渣水泥、快硬水泥、低热水泥混凝土收缩性较高，普通水泥、火山灰水泥、矾土水泥混凝土收缩性较低。另外水泥标号越低、单位体积用量越大、磨细度越大，则混凝土收缩越大，且发生收缩时间越长。例如，为了提高混凝土的强度，施工时经常采用强行增加水泥用量的做法，结果收缩应力明显加大。(2)骨料品种。骨料中石英、石灰岩、白云岩、花岗岩、长石等吸水率较小、收缩性较低；而砂岩、板岩、角闪岩等吸水率较大、收缩性较高。另外骨料粒径大收缩小，含水量大收缩越大。(3)水灰比。用水量越大，水灰比越高，混凝土收缩越大。(4)外掺剂。外掺剂保水性越好，则混凝土收缩越小。(5)养护方法。良好的养护可加速混凝土的水化反应，获得较高的混凝土强度。养护时保持湿度越高、气温越低、养护时间越长，则混凝土收缩越小。蒸汽养护方式比自然养护方式混凝土收缩要小。(6)外界环境。大气中湿度小、空气干燥、温度高、风速大，则混凝土水分蒸发快，混凝土收缩越快。(7)振捣方式及时间。机械振捣方式比手工捣固方式混凝土收缩性要小。振捣时间应根据机械性能决定，一般以5～15s/次为宜。时间太短，振捣不密实，形成混凝土强度不足或不均匀；时间太长，造成分层，粗骨料沉入底层，细骨料留在上层，强度不均匀，上层易发生收缩裂缝。对于温度和收缩引起的裂缝，增配构造钢筋可明显提高混凝土的抗裂性，尤其是薄壁结（壁厚20～60cm）。构造上配筋宜优先采用小直径钢筋(φ8～φ14)、小间距布置(10～15cm)，全截面构造配筋率不宜低于0.3%，一般可采用0.3%～0.5%。四、地基础变形引起的裂缝由于基础竖向不均匀沉降或水平方向位移，使结构中产生附加应力，超出混凝土结构的抗拉能力，导致结构开裂。基础不均匀沉降的主要原因有：(1)地质勘察精度不够、试验资料不准。在没有充分掌握地质情况就设计、施工，这是造成地基不均匀沉降的主要原因。比如丘陵区或山岭区桥梁，勘察时钻孔间距太远，而地基岩面起伏又大，勘察报告不能充分反映实际地质情况。92 (2)地基地质差异太大。建造在山区沟谷的桥梁，河沟处的地质与山坡处变化较大，河沟中甚至存在软弱地基，地基土由于不同压缩性引起不均匀沉降。(3)结构荷载差异太大。在地质情况比较一致条件下，各部分基础荷载差异太大时，有可能引起不均匀沉降，例如高填土箱形涵洞中部比两边的荷载要大，中部的沉降就要比两边大，箱涵可能开裂。(4)结构基础类型差别大。同一联桥梁中，混合使用不同基础如扩大基础和桩基础，或同时采用桩基础但桩径或桩长差别大时，或同时采用扩大基础但基底标高差异大时，也可能引起地基不均匀沉降。(5)分期建造的基础。在原有桥梁基础附近新建桥梁时，如分期修建的高速公路左右半幅桥梁，新建桥梁荷载或基础处理时引起地基土重新固结，均可能对原有桥梁基础造成较大沉降。(6)地基冻胀。在低于零度的条件下含水率较高的地基土因冰冻膨胀；一旦温度回升，冻土融化，地基下沉。因此地基的冰冻或融化均可造成不均匀沉降。(7)桥梁基础置于滑坡体、溶洞或活动断层等不良地质时，可能造成不均匀沉降。(8)桥梁建成以后，原有地基条件变化。大多数天然地基和人工地基浸水后，尤其是素填土、黄土、膨胀土等特殊地基土，土体强度遇水下降，压缩变形加大。在软土地基中，因人工抽水或干旱季节导致地下水位下降，地基土层重新固结下沉，同时对基础的上浮力减小，负摩阻力增加，基础受荷加大。地面荷载条件的变化，如桥梁附近因塌方、山体滑坡等原因堆置大量废方、砂石等，桥址范围土层可能受压缩再次变形。因此，使用期间原有地基条件变化均可能造成不均匀沉降。对于拱桥等产生水平推力的结构物，对地质情况掌握不够、设计不合理和施工时破坏了原有地质条件是产生水平位移裂缝的主要原因。92'