Study On Properties And Computation Of Filling Geotextile Tube

There were many successful engineering applications of geotextile bag of geotextile tubes in the world, because of the advantages of which such as low cost, local materials, construction speed and little impact on surrounding environment. As a relatively new technology, the construction process of the Geotextile bags relied mainly on construction experiences for guidance. In order to provide some theoretical guidance, considering some deficiencies existing in the current studies, the following researches were carried out in this paper:(1) Considering the importance of the permeability of the geotextile in the filling, drainage and consolidation process, and the effects of the tension and other factors on the permeability, a series of experiments were taken to research the permeability characteristics of geotextile under tension with self-designed equipment and the formulae for computing the permittivity was derived with variable head method. The result shows that the permittivity of geotextile under tension is obviously different with that of the geotextile without load. The permittivity is reduced quickly to a stabilized value as the warp tension is increased. The permittivity is increased with the weft tension is increased, however, there is not a stabilized state. The permittivity is also decreased quickly under the influence of the sand particles.(2) Taking into account that the experimental research of filling prosperity of the geotextile tubes is little and the existing experimental data of the tubes is not comprehensive, and considering the operability of the test, an indoor model test was taken to measure the important parameters of the geotubes such as the height, tension, bottom pressure and drainage rate. The observed parameters can be laid the foundation for the further researches and validation for the theoretical studies.(3) Responding to the condition that several tubes rested on rigid foundation with symmetry arbitrary shape, according to the forces equilibrium and geometrical condition of the element of the tube, the control equilibrium equations of the tubes rested on rigid foundation with symmetry arbitrary shape and the solution conditions of which were established with nondimensional method. Then the validity of the method was verified by degradation to flat rigid foundation, and the features of geotubes rested on flat rigid foundation were studied. Then on the basis of the theoretical calculation of impermeable geomembrane bags, by introducing the permeation rate of geotextile into the theoretical method, we deduced the method to calculate filling characteristics of the geotubes rested on flat foundation and foundation of arbitrary symmetry. And the computational theory was verified by the indoor model test data. The results show that the proposed calculation method can be used for calculating the filling features of geotubes in filling process.The creative points of the paper consist that proposing the measuring method of permeability of geotextile under tension while considering the impact of tension and other factors in filling process of geotextile tubes, and introducing the drainage characteristics of the geotextile tubes and the shape of the foundation into the existing theory, which makes the theoretical calculation method simulating more consistent with the actual situation and can provide theoretical guidance for design and construction of the geotextile tubes.