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采用Ritz近似法建立客运专线下承式系杆拱桥侧向稳定承载力实用计算公式; 假定满足拱桥侧向弯扭边界条件的位移试函数, 建立系杆拱桥的主拱肋侧倾失稳结构势能的表达式,基于最小势能原理建立了下承式系杆拱桥侧倾失稳临界载荷实用计算公式. 采用该实用计算公式计算了某客运专线下承式系杆拱桥弹性侧向稳定承载力, 并与三维有限元屈曲计算结果进行比较, 结果表明: 该方法简单实用, 可准确地预测系杆拱桥侧倾临界载荷, 便于工程应用.

LATERAL BUCKLING LOAD OF TIED-ARCH BRIDGE WITH TRANSVERSE BRACES IN RAILWAY PASSENGER TRANSPORT LINE

The practical calculation formula for lateral buckling load of the tied-arch bridge with transverse braces in the railway passenger transport line is proposed using the Ritz approximation method. The trial displacement functions are assumed to satisfy the boundary conditions in lateral flexural torsion buckling conditions. The potential energy
formulations for the arch bridge structure under lateral buckling conditions are determined. The critical lateral buckling load for the tied-arch bridge is deduced based on the minimal potential principle. As an example, the lateral buckling load for a tied-arch bridge in a railway passenger transport line is investigated using the proposed method. The comparison is made between the practical method and the buckling analysis of the finite element method. The result shows that the proposed method is easy to apply and can predict the critical lateral buckling load for the tied-arch bridge precisely.