立体交叉洞室群施工变形三维数值模拟分析

3D Numerical Analysis of Construction Deformation Induced by Metro Station Intercrossing Caverns Excavation

北京地铁14号线蒲黄榆站为3层暗挖车站,设置了由2—1号横通道及8个小导洞,形成了立体交叉洞室群工程。车站工程区地质条件复杂,采用暗挖法施工难度大。为研究此立体交叉洞室群工程施工方案的合理性,采用FLAC3D计算软件对此立体交叉洞室群工程施工力学行为进行了三维数值模拟分析。分析了立体交叉洞室群工程开挖引起的洞室支护结构的应力分布、导洞变形、地层塑性区的分布特征及典型管线正上方地表沉降变形,并将地表沉降现场监控量测数据与计算结果进行了对比分析,结果表明该施工方法可以保证工程施工安全。

Puhuangyu Station of Beijing subway Line 14,has 2—1 transverse passage tunnel and 8 small pilot headings in three layers,in the shape of intercrossing caverns.The complex geological conditions make the excavation of the metro station very difficult.The excavation mechanical behavior of the caverns is investigated by FLAC3D to ensure the reasonableness of the adopted construction method.The emphasis of calculation results is layed upon the stress distribution of support structure,deformation of headings,the plastic zone distribution of surrounding ground and the ground surface settlements above the underground pipelines.Comparation between field measurement data and calculation results has shown that this construction method can guarantee construction safety.