盾构隧道施工引起地表沉降分析与处置

随着隧道施工技术的发展,盾构隧道愈来愈成为软弱岩土层或繁忙闹市地区地下工程施工的主要施工方法。但无论盾构隧道施工技术如何改进,其施工引起的地层移动是不可能完全消除的。为此,本文就盾构隧道施工地层变形特征、地表沉降原因及变形机理、地层变形预测等进行了分析研究,介绍了采用Peck公式预测分析盾构隧道地面沉降量及沉陷槽的方法,并提出了控制地层变形保护建筑物的主要措施,强调了运用数值分析方法对多工况变形进行预测分析仅仅具有指导性,只能作为控制沉降的理论参考,必须在盾构施工过程中加强沉降监测工作,随时了解地面沉降信息,及时采取有效措施,以达到控制沉降和减少损失的目的,为今后地铁设计与施工给予一定的指导。

Analysis and disposal of ground surface subsidence by tunnel shielding construction

With the development of tunnel construction technology,the shielding tunnel becomes the main method of underground construction in weak aquifer or busy downtown area.But no matter how the shielding tunnel construction technology was improved,the caused ground movement could not been eliminated.So in this paper,the ground deformation characteristics,ground surface subsidence reasons and deformation mechanism,and the ground deformation prediction of shielding tunnel construction were analyzed.The method for prediction ground surface subsidence and subsiding geosynclines of shielding tunnel by Peck formula was introduced,and the main countermeasures for controlling ground deformation to protect building were proposed.It was emphasized that conducting prediction on deformation under multi-condition by numerical analysis has only instructive property,and can only be theoretical reference for controlling subsidence.The subsidence monitoring work must be enhanced in the shielding construction process.The ground surface subsidence information should be grasped in any time,and the effective measures should be taken in time,in order to control subsidence and reduce loss.It can provide some guidance for design and construction of subway.