目 录 目 录 ...................................................................................................................................1 1、工程概况 .........................................................................................................................1 1.1 钢箱梁概况 ...............................................................................................................1 1.2 焊接概况 ...................................................................................................................2 1.3 钢箱梁节段划分 .......................................................................................................2 2、编制依据 .........................................................................................................................4 3、材料及焊接方法 .............................................................................................................5 3.1钢材 ............................................................................................................................5 3.2焊接材料 ....................................................................................................................6 3.3 焊接方法 ...................................................................................................................7 3.4 焊材管理 ...................................................................................................................7 4 焊工 .................................................................................................................................7 5 焊前准备 .........................................................................................................................7 6 焊接工艺 .........................................................................................................................8 6.1 焊接顺序 ...................................................................................................................8 6.1.1 总体焊接顺序 .....................................................................................................8 6.1.2 环缝焊接顺序 .....................................................................................................9 6.2焊接方法选择 ..........................................................................................................10 6.3 焊接工艺 .................................................................................................................10 6.3.1 底板对接焊接 ...................................................................................................10 6.3.2 顶板对接焊接 ...................................................................................................11 6.3.3 腹板对接焊接 ...................................................................................................13 6.3.4 腹板与顶、底板T型对接 ...............................................................................14 6.3.5 U形肋的焊接 .....................................................................................................14 6.4 焊接工艺参数 .........................................................................................................16 6.5 焊接注意事项 .........................................................................................................16 6.6 返修工艺 .................................................................................................................17 6.7 焊接的环境要求 .....................................................................................................17 1
6.8 焊接工艺评定 .........................................................................................................18 6.9 焊接工艺流程 .........................................................................................................19 7 雨季施工焊接注意事项 ...............................................................................................20 8、焊接检查 .......................................................................................................................20 8.1 超声波探伤 .............................................................................................................20 8.2 射线探伤 .................................................................................................................21 8.3 磁粉探伤 .................................................................................................................22 9、焊接变形控制措施 .......................................................................................................23 9.1 焊接变形试验 .........................................................................................................23 9.2 焊接变形控制技术 .................................................................................................23 9.2.1 正确选择工艺方法及工艺参数,严格控制线能量 ........................................23 9.2.2 选择合理的施焊顺序和方向 ...........................................................................24 9.2.3 无马板组焊技术。 ...........................................................................................24 9.2.4 U形肋与顶板坡口角接焊缝变形控制 .............................................................24 9.2.5 顶、底板的对接焊接与收缩变形控制 ............................................................25 9.2.6 腹板对接焊缝的焊接与变形控制 ....................................................................25 9.2.7 其它焊缝的焊接 ...............................................................................................25 9.2.8 焊接预热和后热 ...............................................................................................26 9.2.9 焊接变形的观测 ...............................................................................................26 10、钢箱梁焊接质量控制措施 .........................................................................................26 11、焊接安全措施 .............................................................................................................28 11.1 焊接安全防溅措施 ...............................................................................................28 11.2 焊接安全施工措施 ...............................................................................................29 12、焊接设备及辅助设备 .................................................................................................29 2
1、工程概况 1.1 钢箱梁概况 郑州市农业路快速通道项目第九标段工程,主线高架桥在花园路交叉口上部结构设计为三跨变截面连续钢箱梁(50m+70m+50m)。箱梁高为2.0m至3.3米,箱梁主体宽18.9m,两侧的挑梁各宽3.2m,跨中要求钢箱梁有起拱。 钢箱梁箱体材质主要为Q345qD,悬挑装饰板材质为Q235C。桥面板块间采用熔透焊对接,节段间桥面板连接为熔透焊工地对接。顶板板厚16mm、18mm、22mm、28mm。纵肋采用U型肋及I肋,U肋间距为450mm,I肋间距为450mm。横隔板一般间距2.0m,一般横隔板厚均为14mm,部分为12mm,横隔板GA*与GB*交替布置,为便于节段之间现场施焊,横隔板布置有进人孔。箱梁底板一般板厚为16mm、22mm、24mm,支点附近加厚至28mm,每条腹板设3-5道纵向加劲肋。支点处横隔梁由于承受较大的横向荷载,且为加强端横梁的横向刚度,支点处横隔板板厚均为28mm。钢箱梁顶、底面设置2%的横坡,底面与顶面保持平行。本标段钢箱梁标准横断面宽度为25.3m,采用单箱六室结构,桥梁横断面结构形式如下图所示: 图1.1-1 标准段截面示意图 钢箱梁典型节段立体示意图如下图所示: 图1.1-2 主线桥钢箱梁标准节段立体图 1
图1.1-3 主线桥钢箱梁中横梁节段立体图 1.2 焊接概况 1)本工程现场焊接工程量非常大,钢桥主要采用Q345qD钢板。焊接技术要求高,焊接难度高,焊接区域广;主要以高空组装焊接,现场焊接采用手工电弧焊、CO2气体保护焊和埋弧自动焊。 2)焊接接头形式;本工程现场焊接施工节点有: (1)顶板纵向、横向对接焊缝。 (2)底板纵向、横向对接焊缝。 (3)腹板横向对接和横隔板及嵌补段焊接。 1.3 钢箱梁节段划分 根据各联所处的地理位置及吊装施工环境,同时考虑运输条件,对钢箱桥进行了分段,主线钢箱梁进行纵、横向分段,横向分段最大宽度在3.7m,纵向最大长度为13.4m,分段示意图如下图所示。 图1.3-1 横向分段示意图(单箱六室) 2
第8联长170米,横向分8个段,纵向分为18个段,全桥共分为124个块体,最大分段重量为55.9吨,最大分段尺寸为端横梁3051(高)*2190(宽)*13500(长度)和中横梁3485(高)*3600(宽)*12935(长度)。 图1.3-2 第8联钢箱梁分段示意图 图1.3-3 第8联钢箱梁横向分段示意图
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