摘要
研究目的:小净距隧道暗挖施工中,由于邻近导洞之间土柱应力集中,影响其安全状态和邻近后行隧道的施工,并影响到先行隧道的安全,严重的还可能造成周边建筑物、地中管线等设施的破坏。因此,对浅埋暗挖小净距隧道应力集中现象进行分析,对保证施工安全十分重要。研究结论:本文结合宣武门车站小净距群洞暗挖施工,通过实测数据分析应力集中现象,量化了群洞施工时中间土柱的应力应变效应,分析了土柱沉降规律、土压力变化特征,监测结果显示:(1)相邻导洞中土柱体中间部位沉降值最大,达到-14.8 mm,是其他区域的1.1～2倍,土柱体的沉降与土压力的关系和理论分析吻合,表明该部位产生明显的应力集中;(2)后行隧道对先行隧道产生微小的拉力作用。同时,按照开挖面与监测点的距离,对土柱沉降规律和土压力变化规律进行阶段划分,为采取措施降低应力集中现象提供依据。
Research purposes： In the course of subsurface excavation of a little spacing tunnel, the stress concentration of the soil mass between adjacent pilot tunnels influences the safety of the soil mass between two tunnels, the construction of the subsequent tunnel and the previous tunnel, even damages the surrounding buildings and underground pipeline. Therefore, analysis of the stress concentration of a little spacing shallow and subsurface excavated tunnel is very important to ensure the construction security. Research conclusions： In the paper, combined with the subsurface excavation of a little spacing group tunnels at Xuanwumen Station, the stress concentration is analyzed on the basis of monitored and measured data, the stress strain effects of the soil mass between two tunnels during the construction of a little spacing tunnel is quantified, and the settlement regulation of the soil mass and the change characteristics of soil pressure are also analyzed. The results show （ 1 ） The settlement at the center of soil mass between two tunnels is up to - 14.8 mm, being 1.1 ~ 2 times of other areas. The relation between soil settlement and soil pressure is identical with the theoretical analysis. This shows the obvious stress concentration happens at this place. （2） The subsequent tunnel slightly affects the previous tunnel in tension. At the same time, according to the distance between working face and monitoring site, the stages of earth settlement and earth pressure are divided to provide the basis for taking measures for reducing the stress concentration.
出处
《铁道工程学报》
EI
北大核心
2010年第1期42-46,51,共6页
Journal of Railway Engineering Society
关键词
小净距隧道
中间土柱沉降
应力集中
a little spacing tunnel
soil mass settlement between two tunnels
stress concentration
