预应力智能张拉工艺及要点.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,标准化执行,3,智能预应力张拉,桥梁工程预应力混凝土智能张,拉,施,工技术指南,技术交流发言提纲,一,、预应力混凝土发展概述,二、预,应力混凝土施工近况,三、预应力混凝土施工要点,混凝土,混凝土,的主要特点是抗压强度高；抗拉强度低、延伸率小，只为,0.1mm/m,0.15mm/m,。缺点的存在，使混凝土的应用范围受到限制。,钢筋,混凝土,混凝土,混凝土的主要特点是抗压强度高；抗拉强度低、延伸率小，只为,0.1mm,0.15mm/m,。缺点的存在，使混凝土的应用范围受到限制。,为了,利用混凝土抗压强度高的优点，扩大它的应用范围，在混凝土的受拉区配置抗拉强度比它高得多的钢筋，解决了抗拉强度与抗压强度不相适应的矛盾，于是就产生了,钢筋混凝土,，,进入,混凝土的第二个,发展阶段,。,HPB235,钢筋应力达到,40MPa,的时候变形将达到,0.2mm/m,。,预应力,混凝土,将混凝土在承受荷载前对其施压，使它发生预压应力和压缩变形，这种变形在混凝土承受荷载时成为拉伸变形的储备，于是产生了预应力混凝土，进入了混凝土的第三个阶段,。,受拉区,受压区,对混凝土,2000,年,8,月,27,日,，某高架桥,坍塌,混凝土用钢筋强度低,（,370MPa),，,塑性大,，（延伸率,25,）。,采用屈服强度作为重要的强度指标（,235MPa,），一般相当于它的极限强度的,0.85,倍。断裂时有明显的缩颈,（,HPB235,),预应力混凝土用钢绞线强度高,（,1860MPa),，,塑性小，脆性大,，（延伸率,3.5,）,。采用经过,10,秒钟的加荷及卸荷后发生,0.2,永久变形时的应力，作为屈服强度（,1670MPa),，一般相当于它的极限强度的,0.90,倍。断裂时无明显的缩颈,预应力混凝土用钢铰线,1670(1860),采用屈服强度作为重要的强度指标（,235MPa,），,一般,相当于它的极限强度的,0.85,倍,采用经过,10,秒钟的加荷及卸荷后发生,0.2,永久变形时的应力，作为屈服强度,（,1670MPa),，一般相当于它的极限强度的,0.90,倍,。,混凝土用钢筋,强度,370MPa,预应力混凝土用钢绞线,强度,1860MPa,延伸率,25,延伸率,3.5,断裂时无明显的缩颈,断裂时有明显的缩颈,混凝土用钢筋（,HPB235),预应力混凝土用钢绞线,塑性大,塑性小,低,高,1,、整根钢绞线的最大,力,2,、规定非比例延伸力,3,、最大力总伸长率,4,、应力松弛性能,弹性模量,抗拉强度,屈服强度,钢绞线,力,学性能,F,P0.2,90%F,m,预应力混凝土用钢绞线,GB/T5224-2003,260kN,234kN,3.5%,4.5%,1860MPa,1671MPa,初始负荷相当于公称最大力的,80%,，,1000h,后应力松弛率不大于,钢绞线拉伸试验报告,截面面积,规定非比例延伸力,整根钢绞线的最大力,抗拉强度,规定非比例延伸强度,弹性模量,伸长率,平方毫米,千牛,千牛,兆帕,兆帕,兆帕,%,140,256.37,270.56,1930,1830,201940,5.5,国标,234,260,1860,1581,195000,3.5,预应力钢绞线,1,7-15.20-1 860-GB/T5224-2003,0.73,*,1.03,*,1860=1399MPa,张拉控制应力,196kN,对,混凝土预加应力的方法很多，其中大部分是张拉预应力筋并通过粘结力或锚具将反力传给混凝土，使混凝土获得预应力。根据预应力筋张拉时间的先后习惯上把预加应力方法分为,先张法,、,后张法,和,同张法,。,同张法,是在混凝土硬化的同时逐渐张拉预应力筋使它获得预应力。一般是利用膨胀水泥配制混凝土，使它在硬化过程中不但不发生凝缩，反而发生膨胀。在混凝土膨胀的时候，配置在体中的预应力筋就被张拉，而混凝土本身则由于膨胀受到钢筋的限制而同时获得预压应力。人们把这种依靠混凝土自身膨胀来张拉钢筋而产生的预应力。人们把这种依靠混凝土自身膨胀来张拉钢筋而产生的预应力叫做自应力，把采用这种方法的预应力混凝土叫做自应力混凝土。我国目前已采用自应力混凝土大规模生产承插口管道，其最大直径已超过,1200mm,。,先张法,顾名思义，就是在混凝土浇捣前张拉预应力筋，达到要求应力时，用夹具把它临时锚固于承力设备上，等混凝土硬化到一定强度时把它松开，松开时预应力筋发生弹性回缩，并通过粘结力对混凝土施压，使它获得预应力。,53.swf,后张法则是在混凝土浇筑硬化到一定强度时张拉预应力钢绞线。预应力钢绞线张拉到预定应力时，用锚具把钢绞线端部锚固在混凝土端面上，然后在孔道中灌以水泥浆把预应力筋与混凝土粘结在一起。后张法预加应力工艺主要由浇筑混凝土构件、张拉锚固预应力筋和孔道灌浆等三个阶段所组成。,后张法,54.swf,桥梁工程预应力混凝土智能张,拉,施,工技术指南,技术交流发言提纲,一,、预应力混凝土发展概,述,二,、预应力混凝土施工近况,三、预应力混凝土施工要点,国家,强制性标准,混凝土结构工程施工质量验收规范,第,6,.4.2,条,5,的,规定,“,当采用应力控制方法张拉时，应校核预应力筋的伸长值。实际伸长值与设计计算理论伸长值的相对允许偏差为,6,。,”,国家,强制性标准混凝土结构工程施工质量验收规范,GB50204,第,6.4.3,条,规定,“,预应力筋张拉锚固后实际建立的预应力值与工程设计规定检验值的相对允许偏差为,5,。,”,预应力混凝土施工控制要点,预应力混凝土施工控制目标,国家,强制性标准,混凝土结构工程施工质量验收规范,第,6,.4.2,条,5,的,规定,“,当采用应力控制方法张拉时，应校核预应力筋的伸长值。实际伸长值与设计计算理论伸长值的相对允许偏差为,6,。,”,国家,强制性标准混凝土结构工程施工质量验收规范,GB50204,第,6.4.3,条,规定,“,预应力筋张拉锚固后实际建立的预应力值与工程设计规定检验值的相对允许偏差为,5,。,”,预应力混凝土施工控制要点,预应力混凝土施工控制目标,7.12,质量控制与检验,7.12.1,对预应力筋施加预应力时宜对多台千斤顶张拉时的同步性、持荷时间、锚下的有效预应力及其均匀度等进行质量控制，并应符合下列规定：,1,、在采用两台以上千斤顶实施对称和两端张拉时，各千斤顶之间同步张拉力的允许误差宜为,2%,。,2,、张拉至张拉应力时要保证千斤顶具有足够,（,5min,）,的持荷时间。张拉控制应力的精度宜为,1.5%,。,3,、张拉锚固后，预应力筋在锚下的有效预应力应符合设计张拉控制应力，两者的相对偏差不超过,5%,，同一断面中的预应力束其有效预应力的不均匀度应不超过,2%,。,摘自,公路桥涵施工技术规范,（,JTG/T F50-2011,）,观测结,果与,真值之间的接近程度,。,张拉控制应力的精度宜为,1.5%,人员,设,备,材,料,方法,掌握预应力知识和正确操作的施工人员,智能张拉设备,钢绞线,波纹管,锚夹具,锚垫板螺旋筋合格,施工现场具备,：,张拉顺序,、,张拉程序,、,施工作业指导书,、,安全防护措施。,预应力施工控制要点,1,、,2,、,3,、,4,、,5,、,6,、,7,、,环境,理论伸长量的计算与修正,千斤顶拉力与钢绞线根数的匹配,锚具安装正确，混凝土达到要求强度和,7,天龄期,初应力与钢绞线长度对应,管道合格，且安装顺直,不带钢绞线浇筑混凝土,整体穿入梳编束的钢绞线,力的传感,器,精度,0.25%F.S.,杜绝带,钢绞线浇筑混凝土,整体穿入梳编束的钢绞线,预应力人员控制要点,人员、,经培训掌握预应力知识和正确操作的施工人员,7.6.2,施加预应力之前，施工现场的准备工作及结构或构件需达到的要求应符合下列规定：,1,施工现场具备已经批准的张拉顺序、张拉程序和施工作业指导书，,经培训掌握预应力知识和正确操作的施工人员,，以及能保证操作人员和设备安全的防护措施,。,摘自,公路桥涵施工技术规范,p54+5,预应力智能张拉设备,，,由数控液压油泵；电子测量系统、数据采集系统、液压千斤顶；（计算机）控制系统；安全保护装置等部分组成的张拉设备。可实现预应力张拉的应力、应变控制、数据记录,和,即时,打,印施工记录表的功能。,2.0.3,预应力智能张拉设备,由,数控液压油泵；电子测量系统、数据采集系统、液压千斤顶；（计算机）控制系统；安全保护装置等部分组成的张拉设备。可实现预应力张拉的应力、应变控制、数据记录和打印施工记录表的功能。,预应力设备控制要点,设,备,1,、,终应,力,MPa,33.67,33.65,33.26,33.78,33.71,33.48,33.11,33.75,33.82,33.54,33.22,33.93,力,值,kN,972.8,976.8,976.1,968.6,973.9,971.9,971.7,967.7,977.1,973.6,974.9,972.9,目标力,值,kN,976.5,976.5,976.5,976.5,976.5,976.5,976.5,976.5,976.5,976.5,976.5,976.5,偏,差,%,-,0.3,0.03,-,0.04,-,0.81,-,0.27,-,0.47,-,0.49,-,0.90,0.06,-,0.30,-,0.16,-,0.37,目标应,力,MPa,33.79,33.59,33.20,33.98,33.79,33.59,33.20,33.98,33.79,33.59,33.20,33.98,理论伸长量,169,169,169,169,170,170,实际伸长量,173.2,176.3,170.9,173.7,179,175.4,偏差,%,2.5,4.3,1.1,2.8,5.3,3.2,读数,33.79,33.59,33.20,33.98,33.79,33.59,33.20,33.98,33.79,33.59,33.20,33.98,1,2,3,4,0.0346,0.0344,0.0340,0.0348,a,0.0112,0.0471,0.0729,0.0728,b,X=(Y-b)/a,千斤,顶力值,=(,传,感器读,数,-b)/a=971.1,传感器,-,千斤顶标定方程,=(33.61-0.0112)/0.0346=971.1,设备,2,、,张拉,用的千斤顶与传感器应配套标定、配套使用，标定应在经国家授权的法定计量技术机构定期进行，标定时千斤顶活塞的运行方向应与实际张拉工作状态一致。当处于下列情况之一时，应重新进行标定：,1),使用时间超过,6,个月；,2),张拉次数超过,300,次：,3),使用过程中千斤顶或传感器出现异常情况；,4),千斤顶检修或更换配件后。,采用,测力传感器测量张拉力时，测力传感器应按相应国家标准的规定每年送检一次。,预应力设备控制要点,摘自,公路桥涵施工技术规范,p54+5,5.2.3,预应力智能张拉设备,预应力智能张拉设备由数控液压油泵、电子测量系统、数据采集系统、液压千斤顶、控制系统和安全保护装置等部分组成,。,1,数控液压油泵正常工作状态下运行平稳且压力稳定，排出量应为,3.0L,1.0L/min,，排除压力不均匀度不大于,0.10MPa,。,预应力设备控制要点,摘自,桥梁工程预应力混凝土智能张拉施工技术指南,p18+15,设,备,3,、,5.2.3,预应力智能张拉设,备,2,电子测量系统和数据采集系统具备力的测量、记录功能，用于指示和记录力值。力的传感器最大量程不应小于,60MPa,，精度不小于,0.25,级。指示装置和记录装置应随时、准确的指示和记录千斤顶力值。数字式指示装置显示的数字应清晰并以,kN,为单位直接显示千斤顶力值，施加力的过程中指示装置应平稳，无冲击和跳动现象，且直接显示力值。力测量系统应具备调零和清零功能，以及加力速度提示装置。,电,子测量系统和数据采集系统还应具备位移测量、记录功能，用于指示和记录千斤顶行程。位移传感器最大量程不应小于,225mm,，精度不小于,0.25,级。指示装置和记录装置应随时、准确的指示和记录张拉过程中千斤顶行程，数字式指示装置显示的数字应清晰并以,mm,为单位直接显示千斤顶行,程。,预应力设备控制要点,设,备,3,、,压力表精度,最大,量程,允,许,误差,绝对值,读数,相对,误差,%,MPa,MPa,MPa,%,1.6,60,0.96,60,1.6%,1.6,60,0.96,30,3.2%,1.6,60,0.96,15,6.4%,1.6,60,0.96,9,10.7%,1.6,60,0.96,6,16.0%,1.6,60,0.96,3,32.0%,压力表有效读数范围,19.2-40,仪表精度,=,（,绝对误差,的最大值,/,仪表,量程,）,*100%,以上计算式取绝对值去掉,%,就是我们看到的,精度等级,了,.,传感器精度,最大,量程,允,许,误差,绝对值,读数,相对,误差,%,MPa,MPa,MPa,%,0.25,60,0.15,60,0.3%,0.25,60,0.15,30,0.5%,0.25,60,0.15,15,1.0%,0.25,60,0.15,9,1.7%,0.25,60,0.15,6,2.5%,0.25,60,0.15,3,5.0%,传感器有效读数范围,3-40,传感器,5.2.3,预应力智能张拉设备,3,控制系统应具有手动和自动控制两种控制方式，并能绘制力,-,位移、力,-,时间和位移,-,时间曲线，控制方式之间应能实现无冲击切换。自动张拉过程中的控制应采用闭环控制方式；在采用两台以上千斤顶进行同步张拉时，系统应能控制各千斤顶之间的力值同步，且同步张拉力的允许误差不大于,2,；同步张拉过程中各千斤顶和油泵之间应以无线和有线方式进行通信，无线通信有效距离不低于,200m,。软件应具备预应力张拉的全部功能外，还应提供标定、校准的功能；还应提供管道摩阻力试验的功能。,4,安全保护装置应灵敏、可靠。当系统施加力值超过设定力值,2%,时，应能立即停止工作；当千斤顶行进到极限位置时，应能立即停止工作。,预应力设备控制要点,设,备,4,、,预应力材料控制要点,材料,1,、,钢绞线,分批检验时每批质量应小大于,60t,。,检验,时应从每批钢绞线中任取,3,盘，并从每盘所选的钢绞线端部正常部位截取一组试样进行,表面质量、直径偏差和力学性能试验。,预应力筋应保持清洁，在存放搬运过程中应避免使其产生机械损伤和有害的锈蚀。,进场后的存放时间不应超过,6,个月,，应存放在干燥、防潮、通风良好、无腐蚀气体和介质的仓库内；,在室外存放时，不得直接堆放于地面，应支垫并遮盖，防止雨露和各种腐蚀性介质对其产生不利影响。,预应力材料控制要点,材料,2,、,锚具,、夹具和连接器进场时，应按合同核对型号、规格及数量，以及适用的预应力筋的品种、规格和强度等级，且生产厂家应提供产品质保书、产品技术手册、锚固区传力性能型式检验报告，以及夹片式锚具的锚口摩擦损失测试报告或参数。,产品应进行,下列,进,厂检验,：,1,外观检查,；,2,硬度检验,；,3,静载锚固性能试验,。,预应力筋用锚具产品应配套使用，同一结构或构件中应采用同一生产厂的产品，工作锚不得作为工具锚使用。,夹片式锚具的限位板和工具锚宜采用与工作锚同一生产厂的配套产品,。,锚,垫板应具有足够的强度和刚度，且应设置锚具对中止口以及压浆孔或排气孔，压浆孔的内径不应小于,20mm,。,材料,3,、,管,道要对,外观、尺寸,、,集中荷载下的径向刚度,、,荷载作用下的抗渗漏,及,抗弯曲渗漏等进行检验,。,波纹管,存搬运时应采用非金属绳捆扎，或采用专用框架装载，不得抛捧或在地面上拖拉。波纹管在存放时应远离热源及可能遭受各种腐蚀性气体、介质影响的地方，,存放时间不宜超过,6,个月,，在室外存放时不得直接堆于地面，应支垫并遮盖,。,预应力材料控制要点,项目,8,7,6,5,4,3,2,1,平均,波纹管壁厚大于,2.5mm,3.0,3.0,2.6,2.4,2.4,2.9,2.6,3.0,2.7,4,、,5,根钢绞线所用波纹管壁厚标准化,执行,后情况一览,7,塑料波纹管进场时每批应附有出厂合格证和质量保证书，并应做进场复验：,1,）检查波纹管的内径、波高和壁厚等尺寸偏差不超过允许值,。,2,）外观检查时，从每批产品中任意抽取,5,根管材，每根管材上各截取（,300,10,）,mm,试件，两端应与轴线垂直切平，外观应光滑、色泽均匀，内外壁不允许有隔体破裂、气泡、裂口、硬块和影响使用的划伤。,外观质量检测抽取的,5,根产品中，当有,3,根不符合规定时，则该,5,根所代表的产品不合格；如有,2,根不符合规定时，可再抽取,5,根进行检测，若仍有,2,根不符合规定，则该批产品为不合格,。,3,）对波纹管外观、尺寸检查合格的产品，还应做不圆度、环刚度、局部横向荷载、柔韧性、抗冲击性的进场复验。检验试验方法应符合现行预应力混凝土桥梁用塑料波纹管标准（,JT/T 529,）的规定。对波纹管必须严格检验，杜绝管道漏浆。,4,）检验时，应先进行外观质量的检验，合格后再进行其他指标的检验，当其他指标中有不合格项时，应取双倍数量的试件对该不合格项进行复验，复验仍不合格时，则该批产品为不合格。,5,）塑料波纹管应按批进行检验，每批应由同一配方、同一生产工艺、同设备稳定连续生产的产品组成。每批进场后至少抽取,1,组试件并送有相应资质的检验单位进行上述第,3,）条中的性能复验，若波纹管规格种类较多，宜选取三个典型规格进行检验。,8,塑料波纹管使用前应按照附录,A.3,的规定进行简易柔韧性试验，避免管道不合格导致的漏浆堵塞孔道。,材料,4,、锚垫板、螺旋筋,1,预应力混凝土结构或构件所使用的锚垫板应具有足够的强度和刚度，宜设置锚具对中止口、压浆孔、排气孔，压浆孔的内径不宜小于,20mm,。,2,锚具、锚垫板和螺旋筋等产品应配套使用，同一结构或构件中应采用同一生产厂的产品。螺旋筋直径、螺距、圈数以及所使用的钢筋直径不宜小于表,4.2.4,所列参数。,3,锚垫板的最小尺寸应能满足表,4.2.4,对螺旋筋的要求。,预应力材料控制要点,表,4.2.4,螺旋筋直径、螺距、圈数及钢筋直径一览表,（单位：,mm,）,钢绞线,螺旋筋,钢绞线,螺旋筋,根数,大圆直径,钢筋直径,螺旋间距,圈数,根数,大圆直径,钢筋直径,螺旋间距,圈数,4-5,155,10,50,4,14,240,14,50,5,6-7,172,12,50,4,15-16,250,16,60,5,8,185,14,50,4,17,260,16,60,6,9,200,14,50,4,18-19,270,16,60,6,10-12,214,14,50,5,20-22,300,18,60,6,13,224,14,50,5,23-24,330,18,60,6,0,3,2,1,环境,1,：,施工,现场具备已经批准的张拉顺序、张拉程序和施工作业指导,书,。,环境,2,：,能保证操作人员和设备安全的防护措施,。,预应力,环境,控制要点,预应力施工控制要点,要点,1,、,理论伸长量的计算与（考,虑孔道摩阻系数、,钢绞线弹性模量和面积）修正,。,K,=,0.0015,0.17,E,=,195000,序号,实长,弧度,摩擦系数,某,点,应,力,原始数据,kx,(k=0.0015),(=0.17),kx+,e,-(,kx,+,),平均,应力,伸,长,量,累加,坐标,x,坐标,y,0,1358,0,0.948,1,4.530,0.0068,0.0000,0.0068,0.9932,1349,1353,0.031,4.505,1.419,2,1.998,0.1042,0.0030,0.0177,0.0207,0.9795,1321,1335,0.014,1.995,1.523,3,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1289,1305,0.013,1.992,1.397,4,9.203,0.0138,0.0000,0.0138,0.9863,1272,1280,0.060,9.129,0.236,5,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1241,1256,0.013,1.992,0.011,6,6.133,0.0092,0.0000,0.0092,0.9908,1229,1235,0.039,6.133,0.011,7,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1200,1215,0.012,1.992,0.236,8,6.825,0.0102,0.0000,0.0102,0.9898,1187,1194,0.042,6.770,1.097,9,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1159,1173,0.012,1.992,1.223,36.677,0.6101,0.0550,199,0.237,36.500,73.355,损失,0.147,0.474,锚外应力,锚内应力,某工程采用强度等级为,1860,的钢绞线,弹性模量为,195000MPa.,摩擦系数,K=0.0015,=0.17.,计算钢绞线在各点的应力、各段的平均应力以及总伸长量,.,张拉控制应力为,0.73,倍的钢绞线强度等级。锚圈口摩阻力,3,。,1860,0.73=1358MPa,1358,1.03=1399MPa,分段计算伸长量,K,=,0.0015,0.17,E,=,195000,序号,实长,x,弧,度,摩擦系数,某,点,应,力,原始数据,kx,(k=0.0015),(=0.17),kx+,e,-(,kx,+,),平均,应力,伸,长,量,累加,坐标,x,坐标,y,0,1358,0,0.948,1,4.530,0.0068,0.0000,0.0068,0.9932,1349,1353,0.031,4.505,1.419,2,1.998,0.1042,0.0030,0.0177,0.0207,0.9795,1321,1335,0.014,1.995,1.523,3,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1289,1305,0.013,1.992,1.397,4,9.203,0.0138,0.0000,0.0138,0.9863,1272,1280,0.060,9.129,0.236,5,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1241,1256,0.013,1.992,0.011,6,6.133,0.0092,0.0000,0.0092,0.9908,1229,1235,0.039,6.133,0.011,7,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1200,1215,0.012,1.992,0.236,8,6.825,0.0102,0.0000,0.0102,0.9898,1187,1194,0.042,6.770,1.097,9,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1159,1173,0.012,1.992,1.223,36.677,0.6101,0.0550,199,0.237,36.500,73.355,损失,0.147,0.474,某工程采用强度等级为,1860,的钢绞线,弹性模量为,195000MPa.,摩擦系数,K=0.0015,=0.17.,计算钢绞线在各点的应力、各段的平均应力以及总伸长量,.,张拉控制应力为,0.73,倍的钢绞线强度等级。锚圈口摩阻力,3,。,1860,0.73=1358MPa,勾股定理,：,x=,sqrt,（,4.505,2,+,（,1.419-0.948,）,2,）,=,4.530,1,点应力为,:1358,0.9932=1349MPa,0-1,点,平均,应力为,:1354,K,=,0.0015,0.17,E,=,195000,序号,实长,x,弧,度,摩擦系数,某,点,应,力,原始数据,kx,(k=0.0015),(=0.17),kx+,e,-(,kx,+,),平均,应力,伸,长,量,累加,坐标,x,坐标,y,0,1358,0,0.948,1,4.530,0.0068,0.0000,0.0068,0.9932,1349,1353,0.031,4.505,1.419,2,1.998,0.1042,0.0030,0.0177,0.0207,0.9795,1321,1335,0.014,1.995,1.523,3,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1289,1305,0.013,1.992,1.397,4,9.203,0.0138,0.0000,0.0138,0.9863,1272,1280,0.060,9.129,0.236,5,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1241,1256,0.013,1.992,0.011,6,6.133,0.0092,0.0000,0.0092,0.9908,1229,1235,0.039,6.133,0.011,7,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1200,1215,0.012,1.992,0.236,8,6.825,0.0102,0.0000,0.0102,0.9898,1187,1194,0.042,6.770,1.097,9,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1159,1173,0.012,1.992,1.223,36.677,0.6101,0.0550,199,0.237,36.500,73.355,损失,0.147,0.474,2,点,应力为,:,1349,0.9795=1321MPa,1-2,点,平均,应力为,:,1335,19.17,0.1042=1.998,K,=,0.0015,0.17,E,=,195000,序号,实长,弧度,摩擦系数,某,点,应,力,原始数据,kx,(k=0.0015),(=0.17),kx+,e,-(,kx,+,),平均,应力,伸,长,量,累加,坐标,x,坐标,y,0,1358,0,0.948,1,4.530,0.0068,0.0000,0.0068,0.9932,1349,1353,0.031,4.505,1.419,2,1.998,0.1042,0.0030,0.0177,0.0207,0.9795,1321,1335,0.014,1.995,1.523,3,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1289,1305,0.013,1.992,1.397,4,9.203,0.0138,0.0000,0.0138,0.9863,1272,1280,0.060,9.129,0.236,5,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1241,1256,0.013,1.992,0.011,6,6.133,0.0092,0.0000,0.0092,0.9908,1229,1235,0.039,6.133,0.011,7,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1200,1215,0.012,1.992,0.236,8,6.825,0.0102,0.0000,0.0102,0.9898,1187,1194,0.042,6.770,1.097,9,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1159,1173,0.012,1.992,1.223,36.677,0.6101,0.0550,199,0.237,36.500,73.355,损失,0.147,0.474,K,=,0.0015,0.17,E,=,195000,序号,实长,弧度,摩擦系数,某,点,应,力,原始数据,kx,(k=0.0015),(=0.17),kx+,e,-(,kx,+,),平均,应力,伸,长,量,累加,坐标,x,坐标,y,0,1358,0,0.948,1,4.530,0.0068,0.0000,0.0068,0.9932,1349,1353,0.031,4.505,1.419,2,1.998,0.1042,0.0030,0.0177,0.0207,0.9795,1321,1335,0.014,1.995,1.523,3,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1289,1305,0.013,1.992,1.397,4,9.203,0.0138,0.0000,0.0138,0.9863,1272,1280,0.060,9.129,0.236,5,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1241,1256,0.013,1.992,0.011,6,6.133,0.0092,0.0000,0.0092,0.9908,1229,1235,0.039,6.133,0.011,7,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1200,1215,0.012,1.992,0.236,8,6.825,0.0102,0.0000,0.0102,0.9898,1187,1194,0.042,6.770,1.097,9,1.997,0.1265,0.0030,0.0215,0.0245,0.9758,1159,1173,0.012,1.992,1.223,36.677,0.6101,0.0550,199,0.237,36.500,73.355,损失,0.147,0.474,要点,2,、,千斤顶标称张拉力与钢绞线张拉根数匹配符合要求。,预应力施工控制要点,67,张,拉力,83,张,拉力,130,张,拉力,166,张,拉力,200t,100t,3,4,7,8,千斤顶（,t,）,适用钢绞线根数,100,3,4,150,5,6,200,7,8,250,9,10,300,11,12,350,13,14,15,400,14,15,16,17,500,18,19,20,21,4,根钢绞线,250t,千斤顶,活塞面积,4.592,10,-2,张拉控制应力,1399MPa,张拉控制力,=1399,*,4,*,140=783179N,传感器读数约,783179/45920=17.05MPa,（,15%,）,初应力时传感器读数约,=2.56MPa,传感器精度,最大,量程,允,许误,差,绝对值,读数,相对,误差,%,MPa,MPa,MPa,%,0.25,60,0.15,60,0.3%,0.25,60,0.15,30,0.5%,0.25,60,0.15,15,1.0%,0.25,60,0.15,9,1.7%,0.25,60,0.15,6,2.5%,0.25,60,0.15,3,5.0%,精度,0.25,传感器有效读数范围,3-40,预应力施工控制要点,要点,3,、,锚具安装正确，结构混凝土已达到要求的强度和龄期不低于,7,天）,锚具,、夹具和连接器在安装前应擦拭干净。锚具和连接器的安装位置应准确且应与孔道对中。锚垫板上设置有对中止口时，应防止锚具偏出止口。安装夹片时，应使夹片的外露长度基本一致,。,预应力施工控制要点,要点,4,、,选择适宜的初应力、,2,倍初应力，以确定初应力段的伸长量。,钢绞线长度,初应力,2,倍初应力,60m,25%,50%,100m,（实测）,%,2,（实测）,%,预应力施工控制要点,要点,5,、,管道合格。固,定各种孔管道用的定位钢筋的间距，波纹管不宜大于,0.8m,；位于曲线上的管道不宜大于,0.4m,。,管道安装允许偏差：梁长方向,30mm,，梁高方向,10mm,。,预应力施工控制要点,设置,于混凝土中的波纹管，应在浇筑混凝土时内穿芯棒。芯棒应在混凝土初凝后及时抽出。禁止混凝土浇筑前将钢绞线放入孔道中的先穿束工艺的实施,。,要点,6,、,浇筑混凝土前，圆形波纹管宜预穿芯棒，芯棒应在混凝土初凝后及时抽出。,杜绝（桥规允许）带钢绞线浇筑，,1,锈,2,堵,杜绝,:,带钢绞线浇筑混凝土,(,公路桥涵施工技术规范,允许,),截图自交通运输部公路局,高速公路工程施工标准化技术指南,专家宣讲课件,杜绝,:,带钢绞线浇筑混凝土,杜绝,:,带钢绞线浇筑混凝土,1,2,3,杜绝,:,带钢绞线浇筑混凝土,预应力施工控制要点,要点,7,、预应力筋经梳编,束后整体穿入孔道,中，,应保持预应力筋顺直，不发生相互缠绕。,预应力筋应先编束,，,宜每隔,1.0m,1.5m,绑扎一道，对每根预应力筋的首尾部应进行编号（每根预应力筋两端的编号应相同）。然后整束穿入管道，保证预应力筋的顺直、不扭转、相互平行。穿束前宜采用通孔器疏通预留管道，穿束安装时应严格控制每根预应力筋的相对位置（两端对应、平行）。,混凝土浇筑,完成后，,在混凝土终凝,前，用高压水冲洗管道，并用通孔器检查管道是否,畅通。,摘自,高速公路施工标准化技术指南,P23-17,确认,堵孔严重无法疏通的,，应,设法查准堵孔的位置,，凿,开该处混凝土,疏通,孔道,。,钢绞线穿束操作规程,1,、钢绞线下料,钢绞线下料在梁场进行，人工将钢绞线运至编束台架。下料长度严格按照图纸制作。钢绞线切割采用砂轮锯，不得使用电气焊。下料按先长后短的原则进行，经确认长度无误时再切割。下料时不得快速拉动钢绞线，避免钢绞线散盘速度跟不上拉动速度而弯折，钢绞线出现弯折后不得使用。下料中和下料后避免钢绞线受损和污染。,2,、钢绞线编束,钢绞线切割完以后在台架进行理顺，用胶带将切割口缠紧，以防松散及穿束中损伤波纹管，在胶带上写上编号，以备编束用。并间隔,1m-1.5m,用铁丝将钢绞线捆扎编束，切口两侧,5cm,处用细铁丝绑扎，确保同一束钢绞线顺畅不扭结。,3,、钢绞线穿束,钢绞线穿束前应清除预应力孔道内的杂物及积水，穿束必须在混凝土养护结束后进行。钢绞线穿束采用在孔道另一端卷扬机进行牵引，穿束前先用铁丝将卷扬机钢丝绳引至钢绞线侧，用螺旋套将编好束的钢绞线进行包裹（螺旋套底部与钢绞线间用胶带缠紧，防止牵引过程中钢绞线脱落），将卷扬机钢丝绳与螺旋套连接牢靠后再进行穿束。穿束过程中，钢束不得转动，应平直通过孔道。穿出后，检查两端钢绞线的编号，其位置是否对应正确，如不正确应调整一致。穿束后，钢束应能在管道内自由地滑动，否则应立即查明原因，采取措施。,理论伸长量的计算与修正,千斤顶拉力与钢绞线根数的匹配,锚具安装正确，混凝土达到要求强度和,7,天龄期,初应力与钢绞线长度对应,管道合格，且安,装顺直,杜绝带钢绞,线浇筑混,凝土,整体穿入梳编束的钢绞线,提,高张拉应,力应变精度,改,善压浆浆,液充盈度,国家,强制性标准,混凝土结构工程施工质量验收规范,第,6,.4.2,条,5,的,规定,“,当采用应力控制方法张拉时，应校核预应力筋的伸长值。实际伸长值与设计计算理论伸长值的相对允许偏差为,6,。,”,国家,强制性标准混凝土结构工程施工质量验收规范,GB50204,第,6.4.3,条,规定,“,预应力筋张拉锚固后实际建立的预应力值与工程设计规定检验值的相对允许偏差为,5,。,”,智能预应力张拉系统,智能预应力张拉系统,理论伸长量的计算与修正,千斤顶拉力与钢绞线根数的匹配,锚具安装正确，混凝土达到要求强度和,7,天龄期,初应力与钢绞线长度对应,管道合格，且安,装顺直,杜绝带钢绞,线浇筑混,凝土,整体穿入梳编束的钢绞线,提,高张拉应,力应变精度,改,善压浆浆,液充盈度,杜绝带,钢绞线浇筑混凝土,整体穿入梳编束的钢绞线,7.2