Study On The Bearing Capacity And Deformation Property Of Structural Steel Reinforced Trench-cutting Re-mixing Deep Wall Considering The Spatial Variability Of Cement-soil

TRD method,as a new type of cement soil method,can be used to build continuous cement soil wall.When TRD method is applied in supporting structure of foundation pit,the cement soil wall’s bearing capacity and stiffness will be improved after inserting the profile steel into the cement soil wall to form profile steel-cement composite wall supporting structure.This supporting structure can retain soil and water when the excavation depth is less than 10 m in soft soil deep foundation pit.Compared with traditional SMW method,TRD method is more advanced in technique and more feasible in economy.However,there exists a strong spatial variability in the material properties of cement soil wall,which is usually constructed in situ deeply.Thus the carrying capacity of TRD structural steel cement soil wall will be influenced.What’s more,the traditional deterministic design method dose not consider the influence of the inhomogeneous distribution in space of cement soil properties on the carrying capacity of the TRD supporting structure,which often leads to wrong calculation results.In view of this,this thesis analyzed the statistical regularity of cement soil test data of a waterproof curtain construction based on the random field theory,where a series of random data was generated to characterize the spatial variability in the material properties of TRD cement soil wall.FLAC3 D software was used to build the load structure model and the stratum structure model of the TRD structural steel cement soil wall.Meanwhile,the Monte Carlo simulation was used to analyze the influence of the spatial variability of cement soil on the bearing capacity and deformation of the composite structure of steel and cement treated soil.The simulation results were compared with the results of the deterministic analysis method.The calculation results showed that although the main load is supported by the interpolation steel,when the TRD method is used for supporting structure,the cement soil still plays a certain role.And the bearing performance of TRD structural steel cement soil wall is largely influenced by the spatial variability of the strength and modulus of cement soil.The displacement and internal force response of the support structure show obvious variability.In addition,the parameters of the random field model of TRD structural steel cement soil wall were also analyzed in the paper.The influence of the mean value and the variation coefficient of cement soil strength,as well as the correlation distance of the random field on the carrying capacity of the model was discussed.The results of parameter analysis show that the change of the mean value and the variation coefficient of the strength of cement treated soil obviously causes the great alteration of the TRD structural steel cement soil wall’ s carrying capacity.While the results are less sensitive to the vertical correlation distance of the random field.