Abstract:

Based on Biot′s consolidation theory under plane strain, the effect of disposing soft soil foundation using geotextile and plastic drainage plate is studied with nonlinear finite element method. It is shown that the vertical settlement of foundation with drainage plate is larger than that without drainage plate; the lateral displacement decreases and the uplift at the toe of embankment decreases at the same consolidation time. In general, the dissipation time of excess pore pressure is shortened greatly by using plastic drainage plate; the stability of embankment is improved for accelerating the consolidation so as to enhance the bearing capacity of soil. Meanwhile, the shared tensile force of geotextile becomes lower when plastic drainage plate is used. In order to reinforce the embankment effectively, it is advised that geotextile should be set on high-stress zone. Furthermore, the design can be optimized by shortening the standing time of consolidation when plastic drainage plate is used.

Key words: nonlinear finite element method, geotextile, plastic drainage plate, soft soil foundation, consolidation