Study On Bearing Characters Of Pile-Supported And Geosynthetics-Reinforced Embankments

As a relatively new type of foundation treatment method, geosynthetics-reinforced and pile-supported embankments are widely used in many new or renovation and expansion of the highway project. Compared with the traditional method of foundation treatment, geosynthetics -reinforced and pile-supported embankments can reduce soft soil reinforcement area of compression and lateral sliding and can effectively control subsidence and differences subgrade settlement and lateral deformation, and can achieve rapid filling and shorten the construction period, especially suitable for the need for rapid construction or settlement after settlement with differences, there are strict requirements of the project. But geosynthetics -reinforced and pile-supported embankments and interactions involves embankment, geotextile, pile (cap) and original foundation, the bearing traits become very complex. The research is lagging behind, there is no corresponding design specifications or design theories currently, Mostly Relied on experience design, The design and engineering calculation results are not the same sometimes, which easily leads engineering accident. Against a geosynthetics-reinforced and pile-supported embankments expressway soft foundation treatment failures, a research is carried out in this paper, the reason which cause problems is found, the optimization is carried out.Firstly, basing on the previous academic research results, a more mature theoretical approach is chosen to analyze the settlement and bearing capacity of the actual engineering. When carrying onsettlement calculation,by arching effect of embankment fill the earth, pull reinforcement of the membrane effect, interaction between soil and pile pile tip bearing layers were established to support the role of differential equations, and combined with stress and displacement continuity conditions at the junction of the parts, The Matlab computing software is used to solve the value of the distribution of the embankment and soil subsidence difference pile and axial force and lateral friction resistance. In the conventional composite foundation bearing capacity calculated on the basis of theory, the capacity calculation considers the enhancement of embankment fill pressure and reinforced cushion, the contributions to the value of each part of the bearing capacity are carried out.Secondly, against the project examples in this paper, the dedicated software MIDAS/GTS-NX in geotechnical and Tunnel is used to build a three-dimensional model, the numerical results are compared with the theoretical calculation, the modeling and parameter of rationality is verified. Against Practical engineering problems, Embankment deformation and settlement of pile-soil stress, tension and pile grill seriously Force and Displacement is analyzed. The pile efficacy is not big enough will cause the soil borne too large embankment load between piles, and soft soil excessive vertical and lateral deformation in the reinforcement area, subject to excessive shear and moment emergence ruined pile and appear ruined pile in pile side.Last, against the possible causes of the problems, through transforming cloth pile program, obtained the change law of embankment deformation, stress and settlement of pile and soil, grid tension, force of pile with different cloth pile program. Advanced optimization through the numerical simulation results analysis:Keeping the pile spacing of region I constant, increases the pile diameter to 0.4m and add the pile length to 23m; Keeping the pile diameter and length of region II constant, reduced the pile spacing to 2.0m; The diameter, spacing and length of the pile betewen region I and II is 0.3m,2.0m and 23m.