Analysis On Consolidation Settlement And Strength Of Wetland Soft Soil Foundation In Seasonal Frozen Area Of Heilongjiang Province

As a special soil foundation,wetland soft soil has the disadvantages of high compressibility,large void ratio,low shear strength,and so on,which poses a great hidden danger to all kinds of buildings and structures built on it.In this article,the wetland soft soil in the frozen area of Heilongjiang Province was investigated and the soil samples were collected.Combined with indoor physical,chemical and mechanical tests,the basic properties of the soft soil were measured,and the indoor triaxial test and consolidation compression test were emphasized.The shear strength and consolidation characteristics of soft soils under different freeze-thaw cycles,different types of salt,and different salt content were studied.Through the PLAXIS finite element calculation software,the influence of soft foundation treatment measures on soft foundation settlement in different working conditions is simulated.The main research contents are as follows:1)The distribution of wetland soft soils in Harbin,Daqing,and Qiqihar in Heilongjiang Province was investigated,and the basic physical properties indexs,salt content,and organic matter content of soft soils in each region were determined through indoor physical,chemical,and mechanical tests.2)The indoor triaxial test on wetland soft soil in Harbin was carried out,and the shear strength of soft soils under different freeze-thaw cycles,different salt types and different salt content were studied,and the influence of different levels conditions of various factors on the soft soil shear strength index c and ? of soft soil was analyzed,and the law of the experiment was reasonably explained in combination with the microscopic analysis.3)The indoor consolidation compression test on soil samples was carried out,and by collecting data,the d-t curve,e-P relation curve,Cv-P relation curve of the settlement and time under various factors and levels were plotted,and the different levels and settlements d of various factors were plotted.The relationship between indoor consolidation settlement and freeze-thaw cycles,salt type and salt content were analyzed,and the e-P regression equation was fitted by Origin software and analyzed by one-dimensional consolidation theory.Verify that the regression equation fitted well.4)PLAXIS finite element calculation software was used to simulate and analyze the undrained treatment of soft foundation,plastic drainage plate processing,CFG pile treatment three soft foundation consolidation under different working conditions,and the settlement of soft foundation under different working conditions and the relationship between the pressure of super-orifice and the consolidation time was compared.As well as the relationship between the pressure of super-orifice and the consolidation time,the effects of different soft-site treatment measures can be evaluated.