高寒地区土地冻胀对地下连续墙结构的影响

Influences of Frost Heaving on Diaphragm Walls in Frigid Regions

为分析土体冻胀对地下连续墙结构的影响,对越冬期哈尔滨地铁2号线文化宫站地下连续墙进行现场监测,并采用热-力耦合的方式,建立高寒地区地下连续墙结构在土体冻胀作用下的受力分析模型,利用监测数据验证模型的可靠性,进而分析土体冻胀作用对地下连续墙受力性能的影响。结果表明,土体冻胀使得地下连续墙水平位移增大2.0倍,支撑轴力增大2.5～4.6倍;建立的有限元模型可较好的模拟土体冻胀对地下连续墙的影响,土体冻胀导致地下连续墙的支撑轴力增大100MPa。应采取措施降低冻胀作用或在地下连续墙设计中考虑冻胀作用的影响。

Frost heaving has significant influence on the behavior of retaining structures of foundation excavation.However,there is no relevant research on diaphragm walls.To investigate the influence of frost heaving on diaphragm walls,the diaphragm wall of Wenhuagong Station of Harbin Metro Line 2 was monitored on-site.A finite element mode was established using thermal-stress coupled method and was validated by monitoring data,after that it was used to study influences of frost heaving on diaphragm walls in frigid regions.The results show that the horizontal displacement of diaphragm wall is increased twice times by the soil frost heaving,while the support axial force increases 2.5~4.6 times.The finite element model can accurately predict the influence of soil frost heaving on diaphragm walls.The support axial force of diaphragm wall increases 100 MPa because of the frost heaving of soil.Measurements should be taken to reduce the frost heaving effect or influence of frost heaving should be considerd in the design of diaphragm walls.