三向预应力混凝土连续箱梁桥横向加劲肋拓宽研究
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摘要
针对三向预应力混凝土箱梁桥的横向拼接难题,文章提出了一种基于横向加劲肋的新型柔性横向拼接结构。保持新旧箱梁翼缘板分离,在新旧箱梁翼缘板下侧增设沿纵向均匀设置的横向加劲肋,将新旧箱梁翼缘板连接起来,形成一种基于横向加劲肋的柔性拼接结构。依托实际工程,考虑了车辆活载、基础沉降差、新浇筑混凝土的收缩及徐变变形等多重作用,对拼接结构自身及拼接前后既有箱梁的受力状态变化规律进行了较全面的有限元分析。研究表明,拼接拓宽后结构整体刚度有明显提高,且能有效减小旧桥的活载作用效应,说明横向加劲肋能够有效连接新旧箱梁,使得拓宽结构共同受力;在新建桥梁的材料收缩及徐变效应作用下,拓宽后整体结构产生较明显的横向变形,尤其要关注梁端截面的横向变位和加劲肋主拉应力值;在基础不均匀沉降差作用下,各支点截面加劲肋存在较大的主拉应力,可能造成结构开裂损坏,需要采取有效加固措施或进一步优化设计横向加劲肋。此外,文章还研究了加劲肋尺寸参数及布置间距变化对新旧桥梁及加劲肋自身应力的影响,结果表明:柔性加劲肋拼接结构用于三向预应力混凝土连续箱梁桥横向拓宽是可行的,它为类似桥梁拓宽工程提供了一种新的可选择方案。
For the aim of solve the difficulty in 3-way PC box girder bridge widening, a new flexible horizontal stitching structure based on the transverse stiffeners is proposed. Based on a bridge widening practice, the mechanical performance of the flexible stitching structure and the existed box girder after widening is studied in detail, by considering the effect of vehicle load, foundation settlement, new concrete shrinkage and creep deformation. Research shows that the structural stiffness of the whole structure is obviously improved, and the live load effect of existed bridge can effectively be reduced, which shows that the transverse stiffener can eff Due to the effect of shrinkage and creep of new box girder, the whole widening structure produces a more obvious lateral deformation, the lateral deformation of box girder and the tensile stress of transverse stiffeners should be paid on with a particular attention at the end section. Due to the uneven foundation differential settlement, an obvious tensile stress in the transverse stiffeners is formed at each support section, and may cause a structural damage in stiffeners. In addition, the influence of the size and spacing of stiffeners on the stress of the new and old bridges and stiffeners is also studied. The results show that the flexible stiffener joint structure is feasible to broaden 3-way PC box bridge, providing a new alternative scheme for similar bridge widening.
For the aim of solve the difficulty in 3-way PC box girder bridge widening, a new flexible horizontal stitching structure based on the transverse stiffeners is proposed. Based on a bridge widening practice, the mechanical performance of the flexible stitching structure and the existed box girder after widening is studied in detail, by considering the effect of vehicle load, foundation settlement, new concrete shrinkage and creep deformation. Research shows that the structural stiffness of the whole structure is obviously improved, and the live load effect of existed bridge can effectively be reduced, which shows that the transverse stiffener can eff Due to the effect of shrinkage and creep of new box girder, the whole widening structure produces a more obvious lateral deformation, the lateral deformation of box girder and the tensile stress of transverse stiffeners should be paid on with a particular attention at the end section. Due to the uneven foundation differential settlement, an obvious tensile stress in the transverse stiffeners is formed at each support section, and may cause a structural damage in stiffeners. In addition, the influence of the size and spacing of stiffeners on the stress of the new and old bridges and stiffeners is also studied. The results show that the flexible stiffener joint structure is feasible to broaden 3-way PC box bridge, providing a new alternative scheme for similar bridge widening.
引文
[1]吴文清,叶见曙,鞠金荧,等.高速公路扩建中桥梁拓宽现状与方案分析[J].中外公路,2007,27(6):100-104.
[2]吴文佑,吴文清,叶见曙.预应力混凝土桥梁拓宽的若干关键问题研究[J].公路交通科技(应用技术版),2009(8):19-21.
[3]宗周红,夏樟华,陈宜言,等.既有桥梁拓宽改造纵向接缝研究现状与实例分析[J].福州大学学报,2009(2):248-260.
[4]贺铁飞,孙铁钢.既有桥梁拓宽上部结构接缝处理方法分析研究[J].城市道桥与防洪,2012(6):228-230.
[5]翟建勋.大悬臂混凝土箱梁桥横向拓宽拼接加劲肋的设计研究[D].南京:东南大学,2016.
[6]郝曙光.三向预应力连续箱梁桥拓宽的横向拼接构造设计与试验研究[D].南京:东南大学,2012.
[7]谢宝玉.银川黄河大桥拓宽的纵向缝设计[J].公路,2006(2):19-23.
[8]吴文清,翟建勋,林晶.银川黄河大桥横向拓宽拼接构造使用状况调查研究[J].世界桥梁,2015(6):83-87.
[9]Maadani S,Akbari R,Maalek S.Monitoring the dynamic characteristics of an urban bridge before,during and after widening[J].Structure&Infrastructure Engineering,2015,11(7):944-956.
[10]陈娣,刘斌.塘河大桥加宽改造技术方案研究[J].现代交通技术,2007,4(2):52-55.
[11]王林,陈海卿.沪宁高速公路扩建工程塘河大桥拓宽施工[J].世界桥梁,2008(1):22-24.
[12]方志,常红航,阳先全,等.混凝土箱梁桥拓宽拼接后收缩和徐变引起的横向效应[J].中国公路学报,2013,26(6):65-72.
[13]茹毅,刘其伟.收缩徐变作用下混凝土连续箱梁拼宽桥拼接段受力性能研究[J].中外公路,2016(2):196-200.
[14]陈康明,吴庆雄,陈宝春,等.拓宽长联桥梁部分拼接方法与拼接构造试验[J].中国公路学报,2016,29(11):99-107.
[15]刘桂红.长联空心板桥拼接方案研究[J].公路工程,2011,36(5):40-43.
[16]吴文清,叶见曙,华斌,等.沪宁高速公路扩建桥梁拓宽关键技术研究[A].交通部公路科学研究院.全国既有桥梁加固、改造与评价学术会议论文集[C].北京:人民交通出版社,2008:120-129.
[17]Wollmann,G.P.,Anderson,R.B.,&Roberts-Wollmann,C.L.Creep and shrinkage effects in spliced prestressed concrete girder bridges.PCI Journal,2003,48(6),92-105.
[18]韩重庆,冯健,吕志涛.大面积混凝土梁板结构温度应力分析的徐变应力折减系数法[J].工程力学,2003,20(1):7-14.
[19]Bishara,A.G.,&Jang,S.Z.(1980).Settlement-induced forces in concrete bridges.Journal of the Structural Division,106(7),1423-1436.
[20]温庆杰,朱玉晓,王东权.箱梁桥横向拓宽后的基础沉降附加内力分析[J].中国矿业大学学报,2011,40(3):351-356.
[21]Shi,X.,Li,X.,Ruan,X.,&Ying,T.(2008).Analysis of structural behavior in widened concrete box girder bridges.Structural Engineering International,18(4),351-355.
[22]吴胜兴,周氐.大体积混凝土温度应力松弛系数的优化确定[J].河海大学学报(自然科学版),1993(2):47-53.
[2]吴文佑,吴文清,叶见曙.预应力混凝土桥梁拓宽的若干关键问题研究[J].公路交通科技(应用技术版),2009(8):19-21.
[3]宗周红,夏樟华,陈宜言,等.既有桥梁拓宽改造纵向接缝研究现状与实例分析[J].福州大学学报,2009(2):248-260.
[4]贺铁飞,孙铁钢.既有桥梁拓宽上部结构接缝处理方法分析研究[J].城市道桥与防洪,2012(6):228-230.
[5]翟建勋.大悬臂混凝土箱梁桥横向拓宽拼接加劲肋的设计研究[D].南京:东南大学,2016.
[6]郝曙光.三向预应力连续箱梁桥拓宽的横向拼接构造设计与试验研究[D].南京:东南大学,2012.
[7]谢宝玉.银川黄河大桥拓宽的纵向缝设计[J].公路,2006(2):19-23.
[8]吴文清,翟建勋,林晶.银川黄河大桥横向拓宽拼接构造使用状况调查研究[J].世界桥梁,2015(6):83-87.
[9]Maadani S,Akbari R,Maalek S.Monitoring the dynamic characteristics of an urban bridge before,during and after widening[J].Structure&Infrastructure Engineering,2015,11(7):944-956.
[10]陈娣,刘斌.塘河大桥加宽改造技术方案研究[J].现代交通技术,2007,4(2):52-55.
[11]王林,陈海卿.沪宁高速公路扩建工程塘河大桥拓宽施工[J].世界桥梁,2008(1):22-24.
[12]方志,常红航,阳先全,等.混凝土箱梁桥拓宽拼接后收缩和徐变引起的横向效应[J].中国公路学报,2013,26(6):65-72.
[13]茹毅,刘其伟.收缩徐变作用下混凝土连续箱梁拼宽桥拼接段受力性能研究[J].中外公路,2016(2):196-200.
[14]陈康明,吴庆雄,陈宝春,等.拓宽长联桥梁部分拼接方法与拼接构造试验[J].中国公路学报,2016,29(11):99-107.
[15]刘桂红.长联空心板桥拼接方案研究[J].公路工程,2011,36(5):40-43.
[16]吴文清,叶见曙,华斌,等.沪宁高速公路扩建桥梁拓宽关键技术研究[A].交通部公路科学研究院.全国既有桥梁加固、改造与评价学术会议论文集[C].北京:人民交通出版社,2008:120-129.
[17]Wollmann,G.P.,Anderson,R.B.,&Roberts-Wollmann,C.L.Creep and shrinkage effects in spliced prestressed concrete girder bridges.PCI Journal,2003,48(6),92-105.
[18]韩重庆,冯健,吕志涛.大面积混凝土梁板结构温度应力分析的徐变应力折减系数法[J].工程力学,2003,20(1):7-14.
[19]Bishara,A.G.,&Jang,S.Z.(1980).Settlement-induced forces in concrete bridges.Journal of the Structural Division,106(7),1423-1436.
[20]温庆杰,朱玉晓,王东权.箱梁桥横向拓宽后的基础沉降附加内力分析[J].中国矿业大学学报,2011,40(3):351-356.
[21]Shi,X.,Li,X.,Ruan,X.,&Ying,T.(2008).Analysis of structural behavior in widened concrete box girder bridges.Structural Engineering International,18(4),351-355.
[22]吴胜兴,周氐.大体积混凝土温度应力松弛系数的优化确定[J].河海大学学报(自然科学版),1993(2):47-53.