预应力钢束张拉作业指导书

中铁十三局集团有限公司合福铁路安徽段站前二标施工过程限制标准化管理手册编号：ZT13J-SGZD-HD-XX预应力钢束张拉作业指导书编制：审核：批准：201年月日发布201年月日实施中铁十三局集团有限公司第六工程公司目录1目的··············································································22编制依据············································································23适用范围············································································24作业打算············································································24.1技术打算··········································································24.2材料、设备打算·····································································25.劳动组织···········································································25.1劳动力组织方式····································································25.2施工人员结合既定施工方案、机械、工期要求进行合理配置································26材料要求···········································································26.1预应力钢绞线·····································································36.2锚具、夹具········································································37设备机具配置······································································38.张拉程序与工艺流程································································49.施工要求·········································································49.1技术要求·········································································49.2钢绞线下料、穿束···································································49.3锚具及千斤顶安装··································································49.4张拉··············································································59.5伸长量的计算和量测································································510.预应力施工质量限制及检验··························································610.1质量限制·········································································610.2质量检验·········································································611.平安及环保要求····································································7预应力钢束张拉作业指导书1目的：新建合福铁路(安徽段)铜陵长江北引桥（40+56+40）m是施工中重点限制部位，为了确保悬臂浇筑连续梁张拉的施工质量，特编制预应力钢束张拉作业指导书，用以指导此类工程施工。2编制依据：《铁路预应力混凝土连续梁悬臂浇注施工技术指南》TZ324-2010《高速铁路桥涵工程施工质量验收标准》TB10752-2010/J1148-2011《铁路混凝土工程施工技术指南》铁建设［2010］241号《高速铁路桥涵工程施工技术指南》铁建设［2010］241号3.适用范围新建合福铁路(安徽段)铜陵长江北引桥（40+56+40）m悬臂浇筑连续梁张拉施工。4.作业打算4.1技术打算张拉人员仔细熟识图纸规定的施工方法、张拉依次、张拉时间、张拉应力及张拉伸长量；熟识规范规定的张拉要求，及质量标准，计算钢绞线实际下料长度、施工时与设计张拉力对应的张拉油表值、钢绞线各张拉阶段伸长值。4.2材料、设备打算4.2.1依据图纸设计，运用的钢绞线为1×7-15.2-1860-GB钢绞线，钢绞线运用前由试验室对每批钢绞线进行检验，检验合格后才能运用。4.2.2锚具运用前由试验室进行外观、硬度、锚固性能及工艺性能的抽样检验，检验合格的锚具才能运用。4.2.3张拉千斤顶的额定张拉吨位为张拉力的1.5倍，张拉千斤顶在运用前必需经过校正，校正系数不大于1.05，校正有效期为1个月，且张拉次数不得超过300次，千斤顶拆修或更换配件应重新校正。压力表的表面最大读数为张拉力的1.5倍，0.4级校正有效期为1个月。且压力表应与张拉千斤顶配套运用。5.劳动组织5.1劳动力组织方式：采纳架子队组织模式。5.2施工人员应结合施工方案、工期要求、机械配置等合理支配。张拉油表限制人员4人，限制张拉力及油表读数。伸长量测量人员4人。张拉工班长1人，负责张拉速度等整个协调工作。电工1人。6.材料要求6.1预应力钢绞线依据图纸设计，运用的钢绞线为1×7-15.2-1860-GB钢绞线，竖向采纳Ф25PSB785精轧螺纹钢，精轧螺纹钢和钢绞线运用前由试验室对每批钢绞线、精轧螺纹钢进行检验，检验合格后才能运用。6.2锚具、夹具锚具运用前由试验室进行外观、硬度、锚固性能及工艺性能的抽样检验，检验合格的锚具才能运用。7.设备机具配置张拉千斤顶和张拉油泵采纳柳州OVM产品，张拉工作前提前标定，详细数量见下表：预应力施工主要机械设备配备表序号设备名称型号数量1油泵ZB4-50042千斤顶YCW400B43千斤顶YCW60B24千斤顶YDC240QX25卷扬机5T26倒链1T48.张拉程序与工艺流程张拉程序为：0→0.10σk（作伸长量标记）→0.2σk（作伸长量标记）→σk（静停5分钟）→补拉σk（测伸长量）→锚固。（σk为张拉时的限制应力,包括预应力损失在内，其值依据设计图纸要求而定，初应力取σk的10%。）回油自锁锚固，测总回缩量，数据复核回油自锁锚固，测总回缩量，数据复核补油至σk，测伸长值，校核伸长值σk（持荷5min）0.10σk/0.2σk作伸长值标记起先张拉安装千斤顶锚具安装穿束管道清理施工打算预应力张拉工艺流程图9.施工要求9.1.技术要求预应力施工是连续梁工程中最为关键的工序，其施工质量的好坏将干脆影响连续梁的有效预应力值及最终质量。每梁段施工必需在混凝土强度达到设计值95%以上、弹性模量达设计值100%、龄期不少于5d及规范要求后进行。连续梁带模预张拉时，内模板应松开，不应对梁体压缩造成阻碍。9.2钢绞线下料、穿束钢绞线进场并检验合格后，进行钢绞线下料，依据图纸说明，钢绞线下料长度=工作长度+1.56穿束前，先用空压机吹净孔内杂物，并将锚垫板口内的混凝土清除干净，下好料的钢绞线两端用胶布缠牢，整体穿束。穿好的钢绞线应疏整，顺直，不得缠在一起。9.3锚具及千斤顶安装（1）锚具安装前先清洗干净，然后再安装。先装工作锚和工作夹片，安装时留意工作锚在锚垫板限位槽内，工作夹片用套管打入锚孔，外露端应平齐，否则取下重新安装。工作锚和工作夹片安装好后，再安装锚环，锚环应紧扣工作锚。（2）张拉限位器安装时与工作锚对正安装。（3）千斤顶安装时需留意千斤顶油路方向，进油、回油油路不得装反。（4）工具锚安装时应与千斤顶紧扣，工具夹片安装前应缠裹塑料布，并抹少量黄油，以便于张拉完成后卸顶。9.4张拉（1）依据图纸设计要求，本工程张拉要求砼强度达到设计强度达到设计值95%以上及弹性模量达到设计值100%，且龄期不少于5天时进行张拉。（2）张拉前，先检查千斤顶和锚具是否安装好，千斤顶进、回油油路是否正确，确认无误后方可进行张拉。（3）张拉先纵向再竖向精轧螺纹钢，最终张拉横向。张拉时，纵向采纳两端张拉，两侧对称张拉，由外侧向内侧，先长后短张拉依次。竖向和横向均采纳单端张拉。每加5MPa相互通报一次，便于调整两端张拉速度，保持两端一样，张拉达到100%并测量完伸长量后，计算实际伸长量，并与设计伸长量进行比较，当误差大于6%时，应暂停张拉，查明缘由并实行调整措施后再进行张拉。（4）张拉至限制应力后，持荷5min，锚固；若油压稍有下降，须补油到设计吨位的油压值，然后再卸载，卸载时应两端同时进行，并限制卸载速度，卸载速度不能太快。张拉时分级加载，依据10%σk→20%σk→100%σk→补油至100%σk对应的张拉力分别量测伸长值。张拉限制采纳张拉应力和伸长值双控，以张拉应力限制为主，以伸长值进行校核，当实际伸长值与理论伸长值差超过6％时，应停止张拉，等查明缘由并实行措施后再进行施工。9.5伸长量的计算和量测（1）预应力理论伸长值的计算后张法预应力筋理论伸长值及预应力筋平均张拉力的计算公式如下：(1)(2)式中：----预应力筋理论伸长值(mm)----预应力筋的长度(mm)----预应力筋的平均张拉力(N)----从张拉端至计算截面孔道长度(m)----预应力筋截面面积(mm2)----预应力筋的弹性模量(Mpa)----预应力筋张拉端的张拉力(N)----从张拉端至计算截面曲线孔道部分切线的夹角之和(rad)----孔道每米局部偏差对磨擦的影响系数，取0.00782----预应力筋与孔道壁的磨擦系数0.23。（2）实际伸长量的量测及计算方法预应力筋张拉前，应先调整到初应力σ0（一般可取限制应力的10%～20%），伸长量应从初应力时起先量测。实际伸长值除张拉时量测的伸长值外，还应加上初应力时的推算伸长量，对于后张法混凝土结构在张拉过程中产生的弹性压缩量一般可省略。实际伸长值的量测采纳量测千斤顶油缸行程数值的方法。在初始应力下，量测油缸外露长度，在相应分级的荷载下量测相应油缸外露长度。实际伸长值△L的计算公式如下：△L＝B+C-2AA—0～10%σk应力下的千斤顶的实际引伸量B—20%σk应力下的千斤顶的实际引伸量C—20%σk～100%σk应力下的千斤顶的实际引伸量10.预应力施工质量限制及检验10.1质量限制10.110.1.2张拉时，预应力筋伸长值与设计伸长值误差在10.1.3依据图纸设计要求确定张拉依次，10.110.1《铁路预应力混凝土连续梁悬臂浇注施工技术指南》TZ324-2010《高速铁路桥涵工程施工质量验收标准》TB10752-2010/J1148-2011《铁路混凝土工程施工技术指南》铁建设［2010］241号《高速铁路桥涵工程施工技术指南》铁建设［2010］241号10.2质量检验10.2.110.2.210.2.3预应力筋用锚具、夹具和连接器进场时，必需对其质量指标进行全面检查并按批进行外观及外形尺寸、硬度、静载锚固系数性能试验，其质量必需符合设计要求和相关标准的规定。每50