摘要
由于变形监测的滞后,在城市地铁隧道施工中所测到的拱顶下沉通常仅为总下沉量的一部分,并且其所占的比例在不同地层条件下具有较大差异。而隧道拱顶的下沉过程及其最终下沉量则是隧道支护设计及地层环境控制的重要基础。通过对深圳地铁一期工程部分区间隧道拱顶下沉的回归分析认为,隧道拱顶下沉过程遵循指数函数关系,由此可对未量测部分的拱顶下沉量进行预测。通过数值模拟验证了该分析结果的可靠性,并且开挖面前方的超前拱顶下沉量较大。结合隧道开挖应力释放及地下水流失造成的地层失水效应,分析了不同地层条件下拱顶下沉与地表沉降的关系,较好地解释了深圳地铁一期工程建设中拱顶下沉与地表沉降较大而且两者之间呈线性关系的特点,这是由于现场监测滞后以及地层中富水含细砂所致。该成果对城市地铁隧道暗挖施工、支护以及地层环境的控制设计都具有重要的参考价值。
Due to lag of settlement monitoring, measured vault crown settlement is merely a portion of total settlement in construction of city metro tunnel, and ratio of measured settlement to total settlement varies notably with ground condition. Therefore, the vault crown subsiding process and its total settlement are important factors for tunnel supporting design and environment controlling. Regression analysis is carried out on vault crown settlement in some section tunnels of First Stage of Shenzhen Metro, which shows that vault crown settlement process keeps to an exponential function, so the unmeasured vault crown settlement can be predicted. The reliability of regression analysis is validated through numerical simulation; and the larger pre-settlement of vault crown is achieved ahead of heading face. Then, the relation between vault crown settlement and ground settlement is analyzed considering the release of stratum stress during tunnel excavation and stratum water-loss effect caused by the flowing out of underground water; and in this way, the complicated relation of settlements in tunneling of First Stage of Shenzhen Metro may be explained. The complicated relation of settlements is related to the lag of monitoring and water and sand in stratum. The conclusion is significant for the excavation, supporting and environment controlling of city metro tunnels.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2005年第10期1703-1707,共5页
Chinese Journal of Rock Mechanics and Engineering
关键词
隧道工程
地铁隧道
拱顶下沉
地表沉降
监测
预测
Computer simulation
Regression analysis
Roadway supports
Settlement of structures
Subways
Tunneling (excavation)
Underground buildings