摘要
地铁附近的基坑施工是影响区间隧道及地铁车站正常运营的一个重要性因素。若施工方案不当或保护措施不够,很可能引起区间隧道发生过大的不均匀变形。针对基坑开挖对地铁区间隧道的影响评价,本文提出了一种数值方法与解析方法相结合的新方式。首先利用纵向刚度等效和横向刚度等效原则建立了模拟区间盾构隧道的三维等效连续化模型,实现较为精确且方便的三维弹塑性有限元分析;然后采用三次多项式曲线进行拟合,分析基坑开挖各工况下隧道的纵向变形曲率的变化;另外,利用解析推导建立纵向弯矩和管片接头环缝张开量之间的关系,从而实现在三维弹塑性数值模拟结果的基础上结合解析推导的全面评价,为地铁区间隧道的运营阶段保护提供参考。
Excavation near the subway is an important factor that affects normal operations of subway station and tunnels.If either the construction plan or protection measures are inappropriate,too much non-uniform deformation may occur.According to impact assessment of excavation near subway tunnel,a new method that combines numerical method with analytic method is proposed in this paper.First,a 3D equivalent continuum model which simulates the shield tunnel is established depending on the longitudinal stiffness equivalent and the transverse stiffness equivalent,so that an accurate and convenient 3D elastic-plastic finite element analysis is achieved.Then,using cubic polynomial curve fitting to analyze the longitudinal deformation curvature under various excavation operation.In addition,the relation between longitudinal moment and crack size of segment joint girth is established by analytical method,so that the comprehensive evaluation is achieved.All these can provide a guideline for protection of subway tunnel in operation stage.
出处
《地下空间与工程学报》
CSCD
北大核心
2011年第5期1040-1046,共7页
Chinese Journal of Underground Space and Engineering
关键词
基坑开挖
区间隧道
地铁车站
三维等效连续化模型
管片接头环缝张开
foundation pit excavation
running tunnel
metro station
3D equivalent continuous model
crack of shield tunnel segment joint
