摘要
收集中国已有地表沉降监测数据及土体损失率统计分析数据,结合长株潭城际高铁Ⅱ标树木岭盾构隧道进口树木林车站区间16个监测断面数据及其详细地层信息,分析土压平衡盾构隧道施工引起的地层损失规律影响因素。分析表明,土压平衡盾构隧道施工引起的土体损失率的累积概率较好的服从对数正态分布;土体损失率随着埋深或深径比的增大,呈现逐渐减小并趋于稳定的趋势,且两者关系可近似采用幂函数拟合;当H大于20m或H/D大于3.25时,土体损失率基本稳定在0.75%附近,且对应地层信息表明盾构隧道施工时其上覆岩层呈现拱效应,说明盾构隧道施工中其顶部土层成拱效应可较好的控制土体损失;土体损失率或名义土体损失率随着盾构开挖通过时间的增加而逐渐增大,且趋于稳定,说明固结变形对名义土体损失率的影响较大,最大可达瞬时沉降所引起土体损失率的4.58倍。
The observed data of surface settlement and the statistical analysis data of ground loss ratio caused by EPB shield tunnel construction are collected.Combining with the monitoring data and stratigraphic information of the sixteen sections in the interval from tunnel import to Shumuling station of the ChangZhu-Tan intercity high-speed rail II standard,the ground loss and its factors induced by EPB shield tunnel construction are analyzed.The results show that the cumulative probability of ground loss ratio caused byEPB shield tunnel construction better obeys lognormal distribution;with the buried depth and the depth to diameter ratio increasing,the ground loss ratio decreases and tends to be stable,and the relationship between the ground loss ratio and the tunnel buried depth ＆ the depth to diameter ratio can be approximately expressed by power functions;when H greater than 20 m or H/D greater than 3.25,the ground loss ratio is basically stable near 0.75%,and the corresponding stratigraphic information indicates that the overlying strata in the shield tunnel is in the arch effect when constructing.So,it shows that the arch effect of the upper soil layer in the shield tunnel construction can be better control the ground loss ratio.With the increase of the time of shield tunneling through face,loss rate and nominal loss rate of the soil mass gradually increase and tend to be stable.It indicates that the consolidation deformation has great influence on the nominal ground loss ratio,and the maximum value is 4.58 times of the ground loss ratio caused by instantaneous settlement.
出处
《土木建筑与环境工程》
CSCD
北大核心
2017年第5期1-8,共8页
Journal of Civil,Architectural & Environment Engineering
基金
国家自然科学基金(41572275
51478213
51278237)
山东省自然科学基金项目(ZR2012EEM006
ZR2012EEM010)~~
关键词
盾构隧道
土体损失率
固结变形
瞬时沉降
shield tunnel
ground loss ratio
consolidation deformation
instantaneous settlement
