Analysis of Effects of Freeze-thaw Cycles on Deformation and Stability of Deep Foundation Pit Excavation in Typical Soil Layers in Changchun
In order to explore the influence of freeze-thaw cycle on the deformation and stability of deep foundation pit excavation under typical silty clay in Changchun,the underground parking lot project of the First Hospital of Jilin University was taken as the research object and numerical simulation was conducted by finite element software Plaxis2d.The reduction coefficients of soil engineering parameters applicable to typical soil layer in Changchun under the influence of a freeze-thaw cycle are selected.The reduction coefficients of 0.99,0.98 and 0.96 of soil cohesion c,internal friction angle φ and elastic modulus E,which have the greatest influence on foundation pit deformation,are determined to effectively reflect the soil deformation characteristics under a freeze-thaw cycle.Compared with the measured value,the error is small.On this basis,the influence degree of the three factors on the deformation of pile-anchor foundation pit is analyzed,and it is found that the internal friction angle φ is the biggest influence on the deformation of foundation pit support after the soil parameter changes under the influence of freeze-thaw,and the horizontal displacement of foundation pit pile increases by 27%when only 10%is decreased,followed by the elastic modulus E value,which increases the horizontal displacement of pile body by 21%when 10%is decreased.The cohesive force c has little influence on the deformation of foundation pit.
deep foundation pit excavationnumerical simulationpile-anchor supportfreeze-thaw cycle
万方数据
维普
