Effect Of Permeability Of Sand Cushion And Geotextile Reinforcement On Embankment Foundation

Sand cushion and geotextile-reinforcement is often used to treatment of soft clay foundation. With the finite element method, requirement of permeability of sand cushion and the effect of geotextile reinforcement on deformation and stability for embankment are analyzed. The method to determine design pulling forces of geotextile reinforcement is proposed. The conclution is of significance advantage for providing theoretical support for low-cost blowing sand diking technology and compensating foundation strength with geotextile reinforcement.Some developments for low-cost blowing sand diking technology are involved in this paper as below. Firstly key factors for this technique are introduced, such as horizontal draining materials of vertical drains soft foundation, embankment reinforcing effect, the design pulling forces values with geotextile reinforcement and etc. Secondly, a simplified calculation method of the permissive permeability coefficient of horizontal drainage blanket is proposed. In addition, based on the FEM analysis with the software PLAXIS 8.6, effects of permeability of sand on embankment foundation consolidation and stability are studied and the permeability demand of sand cushion is discussed.Furthermore, the various factors influencing effect of geotextile-reinforced on embankrnent and the corresponding influence factor are analyzed in detail. And the experience obtaining value method of the design pulling forces of geotextile reinforcement is given. Finally, emphasis is placed on the case history, a typical engineering in the Baishawan- Shuikou surround beach in Pinghu, Zhejiang. The feasibility that fine sand applies to horizontal drainage blanket of vertical drains soft foundation is verified, and blowing sand diking method is used building embankment on tidal flat of soft clay. Besides, the selection of the constitutive relation with theory and parameters is also verified.