混凝土现浇箱形拱圈与拱架联合作用研究

混凝土箱型拱桥在无支墩拱式拱架上现浇施工时,采用分环分段的施工方法,可以利用拱圈与拱架的联合作用,减少钢拱架的用钢量,达到节省施工成本的目的.通过大型通用有限元软件MSC.Marc2005的模拟及实桥测试数据的分析,发现先期浇注的混凝土拱环与拱架的联合作用明显,拱圈可承担其自重的43%,即拱架只承担拱圈重量的57%,利用联合作用可节约用钢量达30%.同时提出了一个估算拱架承担拱圈重量的公式,该公式简便实用,并通过两种施工工艺的计算结果验证了该公式的准确性,可用于指导初步设计.

Research on Coaction of Concrete Cast in place Box ArchRing and Arch Centering

The construction method of concreting layer by layer and segment by segment could reduce the use of steel and save construction cost,when concrete box arch ring was built cast-in-place with aid of arch centering.According to the simulation of large-scale finite element software MSC.Marc 2005 and the analysis of test data on one arch bridge,the coaction of early built arc ring and arc centering is found significantly.Arch ring can take 43% of its deadweight.In other words,arch centering takes only 57% rather than all of the weight of arch ring.Steel savings amounts to 30% by utilizing the functions.Furthermore,a formula is presented to estimate how much arch centering undertakes the arch ring weight.The formula is simple,practical and accurate,which is confirmed by computation of two different construction technologies.It can be used to guide preliminary design.