摘要
以位于富水砂层中的深圳地铁11号线某区间隧道工程为例,采用有限差分软件建立富水砂层盾构隧道的三维数值模型,模拟分析4种不同支护压力作用下盾构隧道开挖面的稳定性;在此基础上,提出基于稳定系数的开挖面失稳风险分析方法,用于对富水砂层盾构隧道开挖面失稳风险的分析和评估。结果表明:支护压力越接近前方土体的静止水土压力,则开挖面变形越小,开挖面也越稳定;富水砂层盾构隧道的极限支护压力比约为0.4,高于不考虑孔隙水压力时的隧道极限支护压力比。现场实际工程验证表明,基于稳定系数的盾构隧道开挖面失稳风险分析方法可以快速、有效地确定隧道开挖面失稳的风险等级,可用于快速评估富水砂层中盾构隧道开挖面的失稳风险。
Taking certain section tunnel engineering in water-rich sand layer of Line 11 of Shenzhen Metro for example, three-dimensional numerical model of shield tunnel in water-rich sand layer was established by finite difference software to simulate and analyze the stability of excavation face under four different support pressures. On this basis, the analysis method for the instability risk of excavation face based on stable coefficient was proposed to analyze and evaluate the instability risk of excavation face in water-rich sand layer. The results showed that the excavation face was more stable and deformation was smaller while the support pressure was closer to the static water and soil pressure of the soil mass ahead. The limit support pressure ratio of shield tunnel in water-rich sand layer was about 0.4, which was greater than that without considering pore water pressure. Practical engineering has verified that the stability coefficient based method for analyzing the instability risk of excavation face can determine the instability risk grade rapidly and effectively, and this method can rapidly evaluate the instability risk of shield tunnel excavation face in water-rich sand layer.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2015年第6期55-62,共8页
China Railway Science
基金
中央高校基本科研业务费专项资金资助项目(20123227)
关键词
盾构隧道
富水砂层
支护压力
孔隙水压力
开挖面稳定
风险分析
Shield tunnel
Water-rich sand layer
Support pressure
Pore water pressure
Stability of excavation face
Risk analysis
