斜拉桥施工方案
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目 录
一、概述 ···················································································································· 1
二、总体施工工艺 ········································································································ 2
三、主要施工方法 ········································································································ 5
1、施工准备 ········································································································· 5
2、斜拉索的制作、运输、检查验收及存放 ·································································· 9
3、斜拉索提升至桥面 ····························································································· 9
4、斜拉索的塔端挂设 ··························································································· 10
5、桥面放索 ······································································································· 11
2.5.(重点工程)颍河特大桥主塔塔身施工方案、方法与技术措施
颍河特大桥共设置两座斜拉索塔,均为人字形。塔身总高度为38m,分上塔柱(20.443m)和下塔柱(17.557m),上塔柱采用圆端型矩形截面,共设置七道斜拉索,下塔柱为两道独立圆端型矩形柱,与桥墩及箱梁固结。颍河特大桥主塔为本标段施工控制重点。
桥塔布置及断面如图2.5-1所示。
颍河台湾大桥主塔总体布置
主塔塔身剖面图
图2.5-1 桥塔布置及塔身断面示意
2.5.1.下塔柱施工方案、方法
下塔柱全高17.557m,采用C50混凝土,拟定沿塔身垂直方向分4个节段,其中1~3每个节段5m,第4节段2.557。模板系统采用3层模板翻模施工,每层模板高2.5m,外模采用定形钢模板和弧形小模板拼装而成。模板由专业模板厂家加工制造,其强度、钢度、垂直度、同心度、表面光洁度等都应满足要求,以保证其安装、拆卸方便,脱模容易。模板加工好后,应在工厂试拼,确保无误后出厂。
下塔柱为钢筋混凝土结构,无预应力,根部5m内横桥向壁厚由100cm渐变至60cm,顺桥向壁厚由150cm渐变至90cm。
在完成承台施工后,按每节5m浇筑下塔柱。每个节段的施工程序是:安装劲性骨架→绑扎钢筋→立模→验收→浇塔柱混凝土→待强、凿毛、养生→拆模、翻模。
下塔柱施工工艺流程见图2.5.1-1所示。
图2.5.1-1 下塔柱施工工艺流程
2.5.1.1.施工准备
在主塔施工前,精确测量定出主塔的平面位置,放出模板轮廓线,用砂浆找平模板下部的标高,以保证模板的垂直度;将塔柱处承台顶面的混凝土表面进行凿毛处理,并用清水冲洗干净,以保证墩台连接的质量。
2.5.1.2.下塔柱劲性骨架施工
为满足下塔柱高空施工过程中塔柱施工导向、钢筋定位、模板固定的需要,同时方便墩柱施工
脚手架搭设
第n节段钢筋绑扎
第n节段模板安装
第n节段砼浇筑 预埋钢筋绑扎
劲性骨架加工
模板调整
龙源期刊网
斜拉桥钢桁梁悬臂施工架设方案及工艺
作者:张本权
来源:《城市建设理论研究》2013年第04期
摘要:结合重庆东水门长江大桥钢桁梁斜拉桥悬臂架设施工,对跨越长江的钢桁梁桥斜拉桥施工技术展开研究,阐述了重庆东水门长江大桥钢桁梁跨越长江的悬臂施工作业方法,为今后特大桥梁悬臂施工提供了一些可借鉴的经验。
关键词:斜拉桥;钢桁梁;悬臂;架设;工艺.
Abstract: combining the Chongqing east Watergate Yangtze River Bridge steel girder cable-stayed bridge cantilever construction, the crossing of the Yangtze river steel truss cable-stayed bridge
construction technology, this paper research on the Chongqing east Watergate Yangtze River Bridge
steel girder across the Yangtze river cantilever construction operation method for the future, the very
large bridge cantilever construction provides some experience can be used for reference.
Keywords: cable-stayed bridge; Steel girder; Cantilever; Set up; Process.
中图分类号:U415.6 文献标识码:A 文章编号:2095-2104(2013)
主通航孔主跨400米PC斜拉桥施工
斜拉桥梁部采用全预应力混凝土箱型断面型式,梁高3.0m,梁宽34.5m。斜拉桥的大部分工作量集中在两个主塔上,其混凝土量达74600m3,现场工作量大,作业时间长。因此采取设立水上基地、配备水上混凝土工厂的方法,在水上施工斜拉桥主墩及边孔桥墩。上部梁体(除现浇段外)采取岸上预制、水上悬臂拼装。
1、基础施工
主墩钻孔桩穿过淤泥层和淤泥质粘土层、粉质粘土层,持力于粉细砂层。主墩钻孔桩采用定位桩固定平台方法施工。
(1)定位桩平台施工
定位桩用φ1.2m钢管桩,桩长36m,入土约24m。布置在顺桥向主墩承台的两侧。每2根或4根定位桩(桩距2m)构成一个支墩,支墩中心距7m,4根桩的支墩5个,2根桩的支墩4个,各墩桩顶连成整体。定位桩由打桩船插打,完成后在支墩顶安装桩顶联结梁,然后再在主墩两侧的联结梁顶安装工作平台,利用平台和导向架插打钻孔钢护筒。所有钢护筒插打完后,安装护筒支承环,将工作平台支承在联结梁和护筒上,减小平台跨度,并使平台形成牢固的整体,抵抗海浪和台风。
(2)钻孔桩施工
施工平台完成后即可进行钻孔作业,钻孔时泥浆护壁。钻孔机械主要采用KPG-3000型气举反循环旋转钻机,该型钻机最大钻孔直径φ3.0m,钻孔深度130m。另外配备一些GPS-2500型钻机。桩基施工时每墩拟上钻机4台。所有钻孔桩施工安排在7个月内完成。
(3)承台
承台采用吊箱围堰进行施工,吊箱围堰在岸上制造,船运至墩位处拼装,然后用支架液压起吊系统整体起吊就位(也可采用精轧螺纹钢多点吊挂,由护筒顶上的千斤顶下放就位),固定后进行围堰喇叭口堵漏、封底。封底混凝土达强度要求后围堰抽水,切割护筒和凿除桩头,进行承台施工。
承台混凝土按设计要求采用一次或两次灌注(混凝土量达9500
m3),按大体积混凝土要求施工。具体措施如下:
① 选用低水化热的普通硅酸盐水泥。
② 掺加10%~15%的优质Ⅱ级粉煤灰,减少水泥用量。