Research On The New Reinforcement Structure Of Deep Soft Soil Subgrade

Generally,in soft soil ground using traditional passive reinforcement to strengthen embankment,which involves some problems,for instance, long construction period, huge investment, great technical difficulties, settlement deformation after construction. So the closed embankment structure system is proposed in this paper, and study the theory on the internal force, deformation and displacement of bar strip and their influencing factors, internal force and displacement of sheet pile wall, so as to verify the feasibility of the structure system and the superiority in mechanical property.In this paper,chosing the deep soft soil ground of highway as research target,based on theories such as higher mathematics and rock and soil mechanics etc, study on mechanical characteristics, internal force distribution and influencing factors of settlement after construction of the new structure system by numerical simulation software assisted analysis. In light of engineering example, analyzing the results of theoretical calculation and numerical calculation comparatively, shows that the applicability and feasibility of the new structure system, main research results as follows.(1) Analyzing the stress characteristics of bar strip under embankment, on the assumption of it’s cross section keeps invariant after drawing,derive the general deformation equation in vertical load,and study the influencing factors such as filling height、width of embankment,the height of sheet pile wall above original ground, the foundation coefficient and the tension of bar strip.(2) Analyzing the stress characteristics of bilateral rigid sheet pile wall, The main assumptions are:1)sheet pile wall is kept in elastic state and obeys Hook’s law;2) the displacement of sheet pile wall is much smaller than its length;3) the settlement of sheet pile wall is not considered and consider its foot is hinged;4)only consider the component of horizontal force of the bar strip, and seen it as vertical elastic foundation beam, and consider soil pressure and soil resistance of its side.(3)On the basic of without considering the consolidation settlement of soft soil and the fluctuation change of the underground water established2D planar model by Plaxis to analyze the influencing factors of embankment settlement in a relatively comprehensive way, such as filling height,width and slope ratio of embankment,the stiffness of bar strip and sheet pile wall, the ratio of out crop segment and buried segment,the length of embedded segment.(4) In light of engineering example,contrasting the results of theoretical calculation and numerical calculation, which reflected that the results of theoretical calculation and numerical calculation have a good consistency and shows high reliability of the theory formula and its applicability and feasibility under certain engineering background.