既有地铁隧道上方明挖基坑施工方案分析
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摘要
明挖基坑施工对邻近地铁隧道的影响是工程设计和施工中的难点。选取杭州市延安路至仁和路过街通道基坑开挖作为工程案例,采用三维有限元分析的方法,针对地铁隧道上方浅覆土工况,基坑开挖中采用地基加固、分期开挖等技术方案以减少对既有地铁隧道的影响,提出门式框架加固、分期开挖及控制降水等保护措施。研究结果表明,施工期各监测数据稳定合理,数值模拟与现场实测数据基本吻合,基坑开挖保护措施切实有效。
The influence of open-cut excavation on the nearby metro tunnels is one of the difficulties in engineering design and construction. A three-dimensional finite element(FEM)method is used to analyze a practical project of cross-road foundation pit in Hangzhou metro. In view of the shallow soil above the metro tunnel,the implementation of foundation rein-forcement,staged excavation and other technical schemes in the foundation pit excavation is discussed,in order to reduce the engineering influence on the existing tunnels. At the same time,protection measures like portal frame reinforcement,stratified partition excavation and control precipitation are put forward. The research shows that the detected data are stable and reasonable during the construction,the numerical simula-tion and field measurement data are basically consistent,prov-ing the effectiveness of the protection measures.
The influence of open-cut excavation on the nearby metro tunnels is one of the difficulties in engineering design and construction. A three-dimensional finite element(FEM)method is used to analyze a practical project of cross-road foundation pit in Hangzhou metro. In view of the shallow soil above the metro tunnel,the implementation of foundation rein-forcement,staged excavation and other technical schemes in the foundation pit excavation is discussed,in order to reduce the engineering influence on the existing tunnels. At the same time,protection measures like portal frame reinforcement,stratified partition excavation and control precipitation are put forward. The research shows that the detected data are stable and reasonable during the construction,the numerical simula-tion and field measurement data are basically consistent,prov-ing the effectiveness of the protection measures.
引文
[1]刘国彬,黄院雄,侯学渊.基坑工程下已运行地铁区间隧道上抬变形的控制研究与实践[J].岩石力学与工程学报,2001,20(2):202.
[2]陈郁,张冬梅.基坑开挖对下卧隧道隆起的实测影响分析[J].地下空间与工程学报,2004,24(增刊1):748.
[3]刘小建,贾坚.地铁隧道上方基坑卸荷回弹及控制的试验和探讨[J].地下工程与隧道,2008(2):41.
[2]陈郁,张冬梅.基坑开挖对下卧隧道隆起的实测影响分析[J].地下空间与工程学报,2004,24(增刊1):748.
[3]刘小建,贾坚.地铁隧道上方基坑卸荷回弹及控制的试验和探讨[J].地下工程与隧道,2008(2):41.