预应力钢束张拉作业指导书_精品文档.doc
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中铁十三局集团有限公司合福铁路安徽段站前二标
施工过程控制标准化管理手册
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··············································································2
2编制依据············································································2
3适用范围············································································2
4作业准备············································································2
4.1技术准备··········································································2
4.2材料、设备准备·····································································2
5.劳动组织···········································································2
5.1劳动力组织方式····································································2
5.2施工人员结合既定施工方案、机械、工期要求进行合理配置································2
6材料要求···········································································2
6.1预应力钢绞线·····································································3
6.2锚具、夹具········································································3
7设备机具配置······································································3
8.张拉程序与工艺流程································································4
9.施工要求·········································································4
9.1技术要求·········································································4
9.2钢绞线下料、穿束···································································4
9.3锚具及千斤顶安装··································································4
9.4张拉··············································································5
9.5伸长量的计算和量测································································5
10.预应力施工质量控制及检验··························································6
10.1质量控制·········································································6
10.2质量检验·········································································6
11.安全及环保要求····································································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是施工中重点控制部位,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.作业准备
4.1技术准备
张拉人员认真熟悉图纸规定的施工方法、张拉顺序、张拉时间、张拉应力及张拉伸长量;熟悉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、设备准备
4.2.1预应力钢绞线
根据图纸设计,使用的钢绞线为1×7-15.2-1860-GB钢绞线,钢绞线使用前由试验室对每批钢绞线进行检验,检验合格后才能使用。
4.2.2锚具、夹具
锚具使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使用。
4.2.3张拉设备
张拉千斤顶的额定张拉吨位为张拉力的1.5倍,张拉千斤顶在使用前必须经过校正,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使用。
5.劳动组织
5.1劳动力组织方式:
采用架子队组织模式。
5.2施工人员应结合施工方案、工期要求、机械配置等合理安排。
张拉油表控制人员4人,控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
根据图纸设计,使用的钢绞线为1×7-15.2-1860-GB钢绞线,竖向采用Ф25PSB785精轧螺纹钢,精轧螺纹钢和钢绞线使用前由试验室对每批钢绞线、精轧螺纹钢进行检验,检验合格后才能使用。
6.2锚具、夹具
锚具使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使用。
7.设备机具配置
张拉千斤顶和张拉油泵采用柳州OVM产品,张拉工作前提前标定,具体数量见下表:
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
ZB4-500
4
2
千斤顶
YCW400B
4
3
千斤顶
YCW60B
2
4
千斤顶
YDC240QX
2
5
卷扬机
5T
2
6
倒链
1T
4
8.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为张拉时的控制应力,包括预应力损失在内,其值根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
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
开始张拉
安装千斤顶
锚具安装
穿束
管道清理
施工准备
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直接影响连续梁的有效预应力值及最终质量。
每梁段施工必须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,根据图纸说明,钢绞线下料长度=工作长度+1.56m。
钢绞线切割必须采用砂轮切割机切割,不得使用电弧切割,切割前用铁丝将切割部位两侧捆扎牢固,以避免切割后的钢绞线散头。
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,安装时注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)千斤顶安装时需注意千斤顶油路方向,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)根据图纸设计要求,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,最后张拉横向。
张拉时,纵向采用两端张拉,两侧对称张拉,由外侧向内侧,先长后短张拉顺序。
竖向和横向均采用单端张拉。
每加5MPa互相通报一次,便于调整两端张拉速度,保持两端一致,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,查明原因并采取调整措施后再进行张拉。
(4)张拉至控制应力后,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,并控制卸载速度,卸载速度不能太快。
张拉时分级加载,按照10%σk→20%σk→100%σk→补油至100%σk对应的张拉力分别量测伸长值。
张拉控制采用张拉应力和伸长值双控,以张拉应力控制为主,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,等查明原因并采取措施后再进行施工。
9.5伸长量的计算和量测
(1)预应力理