开挖卸荷对下卧初支隧道的纵向变形的影响研究

结合目前已有的分析方法，对下卧初支隧道的纵向变形进行了施工前的预测，并获得了不同的结果。但现场的监控量测证明了开挖卸荷导致下卧既有初支隧道的纵向变形出现了不同的时空分布规律，并印证了时空效应对下卧初支隧道纵向变形的影响是不容忽视的。基坑开挖卸荷的速度和方式是直接影响既有隧道纵向变形的关键因素之一。通过对下卧隧道纵向变形的实测数据分析研究，总结了实例工程的经验和教训，为今后的类似工程提供了参考。

Research on vertical deformation of down shotcrete tunnel during unloading of pit excavation

According to existing analysis methods, the vertical deformation of down tunnel has been predicted and reached different results. But it is proved by in-site measuring that the vertical deformation of down tunnel behaves in different time-space laws because of quick excavation. It is important to take into account time-space effect when the vertical deformation of down shotcrete tunnel happens. Velocity and mode of deep-dip excavation is one of key factors of vertical deformation. Based on analysis and study of in-site measuring data, some useful experience and lesson has been concluded. It may be useful reference to similar engineering in future.