摘要
以南宁地铁一号线广白区间盾构施工为背景,采用有限元软件对双线盾构施工过程进行了全过程模拟,并通过与实测数据的对比分析,揭示了圆砾地层双线盾构施工的地表沉降特征,及不同开挖面压力、注浆参数对地表沉降的影响,并对施工提供了一些建议。分析表明,圆砾地层中施工对周围土体的扰动更为明显,使得左右线隧道施工相互影响更大;当开挖面压力减小较多时,开挖引起的地表竖向位移影响范围明显增大,施工中应在理论计算和经验的基础上适当增大开挖面压力,尽量避免开挖面压力过小或者失压;增大注浆层刚度对减小沉降值作用非常明显,在地表沉降控制要求严格的区段,应适当增加注浆压力,并保证注浆量,必要时应进行二次补注浆。
Based on the tunnel construction in Nanning Metro Line 1,this paper employs FEM to simulate double-line tunnel excavation. Through comparing the numerical result with the monitoring data,the ground settlement characteristics and boring parameters sensitivity in circular-gravel layer is revealed. The conclusions are as follows:mutual influence between the tunnels is much bigger because the construction disturbance in circular-gravel layer is obvious; the influence scope on ground settlement increases dramatically when the excavation surface pressure decreases a lot,which should be avoided in practice; increasing grouting rigidity is a very effective way to reduce ground settlement,which should be employed when there is a high requirement for ground settlement control and if necessary,secondary grouting should be done.
出处
《地下空间与工程学报》
CSCD
北大核心
2015年第S2期698-705,共8页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(41372276)
关键词
圆砾地层
盾构
地表沉降
参数分析
circular-gravel layer
shield tunneling
ground settlement
parameter analysis
