与既有隧道平行小净距的新建连拱隧道设计、施工方案优化研究

Study on Optimization of Design and Construction Schemes of Newly Built double-arched Tunnel Paralleling to Existing Tunnel in Small Net Spacing

分析新建隧道对既有隧道的影响,并对既有隧道的安全度进行合理评价,是实际工程中经常遇到的难题。拟建的新疆乌鲁木齐市雅山连拱隧道工程,与既有隧道平行、小近距。现根据该隧道工程在设计施工中遇到的实际难题,就新建隧道施工对既有隧道的影响展开分析研究。经优化分析,通过严格执行"早封闭、二衬紧跟",尽早完成支护结构施作,采用合理的施工工法,并对新建隧道底部进行注浆加固,可有效地减小新建隧道对既有隧道的影响。其成果可供国内类似工程参考。

The analysis of the influence of newly built tunnel on the existing tunnels and the reasonable assessment of the safety of the existing tunnel are the difficulties often met in the practical projects. The proposed Xinjiang Urumqi Yashan Double-arched Tunnel Project is parallel to the existing tunnel in small spacing. According to the practical difficulties met in the design and construction of this tunnel project, the article analyzes and studies the influence of newly built tunnel on the existing tunnels. Based on the optimized analysis, it is strictly to implement the method of'early closure and two-lining closely followed', to complete the construction of supporting structure as soon as possible, to use the reasonable construction method, and to implement the grouting reinforcement at the bed of newly built tunnel able to efficiently decrease the influence of newly built tunnel on the existing tunnel. Its result can be referenced for the similar projects in China.