浅埋大跨径连拱隧道不同施工方案对比分析

Simulation of Shallow Buried Large Span Multi-arch Tunnel in Construction Process

在山岭重丘区高等级公路建设中,受地形、地质条件和线路平、纵、横指标及三项指标组合设计的制约、工业城区条件的影响,经常采用连拱隧道。连拱隧道具有线形流畅,空间利用率高,占地面积较少,与洞外线路连接方便以及有利于保护环境等优点,因此在我国高速公路建设中应用越来越广泛。通过数值模拟对浅埋大跨径连拱隧道不同施工方案围岩应力场、位移场和塑性区变化规律进行了数值分析,从而有效揭示出不同施工方案各阶段围岩应力集中位置和潜在塑性破坏区,不仅为隧道的安全顺利施工提供了预警信息和直接指导,同时为连拱隧道的优化设计提供可靠的理论依据,为浅埋大跨径连拱隧道施工过程合理设计、监控预警、分析评价与应急处治提供依据。

The multi-arch tunnel is always applied to the high-grade highway construction in the mountainous area where faces multi-restraints of terrain, geological conditions, industry city conditions, and road technical indexes of plan, profile, and horizontal parameters. With the merits of streamline, high space utilization ratio, low land occupation, convenient connection with outside access, and favorable for environmental protection etc. , the multi-arch tunnel has been used widely in the road construction of China. In the paper through numerical simulation, surrounding rock stress field, displacement field and variation regulations of plasticity zone under different construction schemes are analyzed, which unveils the concentration positions of surrounding rock stress and potential plasticity damage zone, hence settle a good foundation for appropriate designing, monitoring, early warning, appreciating and emergency treatment.