摘要
结合上海2010年世博会专用隧道西藏南路越江隧道穿越已运营地铁M8线工程,针对大直径泥水盾构在砂性承压水土层中近距离穿越已建地铁隧道的难题展开研究。借助有限元模拟、现场试验、实时监测等方法,分析了地层损失率、切口水压与沉降的关系,研究结果表明:通过精心施工,最大地层损失率可以控制在4‰以内,二次穿越引起的沉降因土体二次扰动而显著增加,斜向穿越时沉降槽呈不对称分布,沉降主要发生在管片拼装阶段,穿越过程宜采用快推方式,提高切口水压对沉降控制无明显影响。结论可供类似工程参考。
The influence of large slurry shield under existing adjacent metro tunnel is analyzed based on South Xizang road tunnel under-crossing M8 metro tunnel which happenes in cohesionless soil with cofined water.By FEM software,onsite testing and monitoring,the relationship between ground loss ratio,slurry pressure and tunnel settlement were studied.The results demonstrate that ground loss ratiis can be confined below 4‰ by rigorous control.Settlement of the second crossing remarkably increases because the soil is disturbed.Settlement curve of inclined crossing shows unsymmetrical distribution.The great mass of settlement happens when liners are assembled and quick driving is helpful to control sinkage.Increaseing slurry pressure has no notable influence to settlement controlling.Conclusions would be helpful for the future similar projects.
出处
《施工技术》
CAS
北大核心
2010年第S1期223-227,共5页
Construction Technology
关键词
盾构隧道
穿越施工
有限元
现场监测
沉降
地层损失率
shield tunnel
crossing construction
finite element
onsite monitoring
settlement
formation loss ratio
