全断面硬岩地层盾构隧道管片上浮控制技术研究

摘要

In this paper,the causes and mechanisms of the up﹣floating of the segment rings of a shield﹣bored tunnel on No.7 Line of Guangzhou Metro,which is located in full﹣face hard﹣rock ground,are analyzed in terms of mechanical conditions and space conditions,so as to ensure the quality of the segment lining.Countermeasures,including pea gravel backfilling behind the segment rings,prevention of gout loss by means of grout stopping rings and water﹣stopping rings,improving the backfilling effect of the simultaneous grouting by adopting semi﹣open boring mode,and installing cylinders at the bottom of the front shield to avoid shield pitching,are proposed.%为了解决盾构在全断面硬岩地层中管片上浮的问题，确保管片衬砌的施工质量，结合广州7号线某全断面硬岩段的盾构施工，从力学条件和空间条件等方面分析了导致管片上浮的原因和机制，从盾构施工和设计等方面提出了减小管片上浮的新措施。包括：采用豆砾石回填灌浆工艺进行管片壁后填充、利用止浆环与隔水环防止浆液流失、半敞开式掘进提高同步注浆的填充效果、采用前盾底部设计千斤顶防止盾构栽头等。