下承式3跨连续梁拱组合桥梁实用计算方法

通过引入坦拱、吊杆力相等、等效膜张力等假定,用力学方法推导了下承式3跨连续梁拱组合桥梁拱肋荷载分担比、主梁跨中挠度、拱肋跨中挠度的计算公式.通过改变结构参数,建立了多个桥梁模型,并将各模型下公式计算结果与有限元计算结果进行对比,验证了计算公式的正确性.为了使二者的计算结果更加接近,通过误差分析,对公式进行了修正.拱肋荷...

A Practical Computational Method for Three-span Continuous Beam-arch Through Bridge

Some formulae for a three|span continuous beam|arch through bridge subjected to a uniformly distributed load were developed to calculate the load sharing ratio of arch, mid|span deflections of beam and arch. For a series of bridges with various structural parameters, the results obtained by the established bridge models and the derived formulae  are generally in accordance with those by finite element analysis (FEA). To minimize the discrepancy between the results of the current approach and FEA, one modification factor was employed to improve the accuracy of the proposed formulae. The relative calculation error of the modified formulae is normally less than 3% for load sharing ratio of arch, 10% for mid|span deflection of beam and 20% for mid|span deflection of arch. Finally, a parametric study was conducted to investigate the influences of various structural parameters on the load sharing ratio between the arch and the beam. The modified formulae and the parametric analytic result will provide a useful guidance in the preliminary design of the bridges with similar structural styles.