Abstract: Aiming at the closure temperature difference occurring in long span arch bridge，and taking the construction of Xinlongmen Bridge as a case study，the influence of closure temperature difference on the arching figure，the stress and the carrying capacity of long span arch bridge is analyzed，by establishing the analysis model by means of ANSYS finite element program． The research proves that the closure temperature difference has obvious effect on the figure of the joining segment， the foot section stress of upper chord and crown section stress of latter chord． If the closure temperature difference is above twenty-wo centigrade，adjustment measures should be taken before the closure in order to ensure the arching figure and stress within the reasonable range．

Key words: closure temperature difference, long span arch bridge, figure, stress, carrying capacity

摘要： 针对大跨度拱桥合龙温差的问题，以新龙门大桥工程为依托，借助ANSYS 有限元程序建立分析模型，开展了 合龙温差对大跨度拱桥成拱线形、应力及承载力影响的分析。结果表明: 合龙温差对合龙段线形、上弦杆拱脚截面 应力、下弦杆拱顶截面应力都有显著影响。当合龙温差大于22 ℃时，为保证成拱线形及应力处于合理范围内，需 要在合龙前采取调整措施。

关键词: 合龙温差, 大跨度拱桥, 线形, 应力, 承载力