大跨径波形钢腹板连续箱梁桥设计与施工关键技术

摘要

桃花峪黄河大桥跨北大堤桥为（75＋135＋75） m 波形钢腹板连续箱梁桥，对该桥设计与施工关键技术进行研究。设计阶段研究得出：与预应力混凝土连续箱梁桥相比，波形钢腹板连续箱梁桥具有景观效果好、抗震性能好、施工效率高等优点，确定该桥采用波形钢腹板连续箱梁桥；对比工程造价，确定高跨比取1/18；采用有限元法分析横隔板数量对箱梁抗扭刚度和畸变的影响，确定中、边跨分别设置8道、4道横隔板；对3种型式连接件进行试验研究，确定波形钢腹板与顶、底板分别采用 Twin-PBL 和角钢连接；预应力采用体内和体外混合配束方案，确保维护方便。施工阶段研究得出：随跨径增大，施工位移增量对波形钢腹板加工尺寸影响显著，加工时必须考虑其影响；采用“悬臂桁车技术”保证了钢腹板起吊和安装定位；采用先边跨后中跨合龙方案，确保了大桥顺利合龙。%The North Embankment Bridge of Taohuayu Huanghe River Bridge is a (75 + 135 +75) m continuous box girder bridge with corrugated steel webs .The key design and construction techniques of the bridge were studied .The study into the design stage indicates that the continuous box girder bridge with corrugated webs is superior to the prestressed concrete continuous box gird -er bridge in terms of the aesthetic effect ,seismic performance and construction efficiency ,there-fore ,it is chosen for the bridge .For the sake of construction cost ,the ratio of the height of the corrugated webs to the span length adopts 1/18 .The finite element method was used to analyze the influence of amount of diaphragms on the torsional stiffness and distortion of the box girder .It was determined that eight and four diaphragms were set respectively for the intermediate and side spans .Three types of connectors were experimentally studied ,and by the results which the corru-gated steel webs were determined to connect to the top and bottom slabs respectively by Twin-PBL and angle steel .Moreover ,external and internal prestressing tendons were matched to ensure the convenience of future maintenance .The study into the construction stage indicates that as the span length increases ,the influence of the construction displacement increment on the machining dimen -sion of corrugate steel webs becomes more significant ,which should be taken into account during the process of fabrication .The lifting and installation position were carried through by using the "cantilever truss trolley technique" .To ensure the smooth closure of the bridge ,the scheme of clos-ing the side spans first and intermediate span later was adopted .