中文摘要：

结合湖南省长沙市橘子洲大桥西桥头拓改工程，讨论了双曲拱桥一端采用连续箱梁桥拓展改造施工过程中的关键问题。分析结果表明：在施工控制恰当的情况下，可以防止原拱桥主拱圈开裂损伤；桥梁变位监测结果对修正施工措施、保证施工效果具有重要的指导作用；桥梁结构应变受温度影响的变化量大于受施工影响的变化量；电阻应变仪以及手持式应变仪在野外测试时，受环境干扰较大，所测应变值甚至超过较小结构的荷载应变值。

英文摘要：

Associating with the west end expansion engineering of Changsha Juzizhou Bridge, Hunan Province, some key problems arising in the expansion project of multi-span double arch bridge expanded by continuous bridge were discussed. Analytical results show that the reasonable construction control can prevent the original multi-span arch bridge from cracking. The revising of construction measurement will benefit from the displacement monitoring data. The varying magnitude of the structural strain created by the varying temperature is greater than the expansion construction. During the field measuring by metal strain gauge or manual strain gauge, the interference affection of environment is great, and the measuring strain is greater than the structural strain by loads.