Study On Deformation And Mechanical Properties Of Geotextile Tube

Geotextile tubes were widely used in the fields such as the reclamation of tideland, the protection of seacoast and the construction of harbor. Effects caused by the parameters were sometimes ignored during the applications of geotextile tube due to the limits of the experiences summarized by the constructions, resulting in the backwardness of the theoretical research. This paper was mainly focused on the research of the following points in order to provide the theoretical directions of the silting of the geotextile tube as well as to find out the inadequacy of the resent research.(1) In the two comparative model tests, the cross-sectional form of geotubes in the model was different while the circumference of the cross-section was the same, and in the process the same weight and kind dry sand was filled into measure the shape and distribution of the tension of geotextile tubes which were under the action of its own weight. Comparing the two results of the two models, under the action of its own weight, forming an arc-shaped geotubes, and also comparing the shape and tension of the sand bags, the sand bags of two different initial forms could eventually form the same stable state, and the tension distribution trend and the maximum tension was basically the same, which verified the correctness of steady-state sand bags.(2) Assuming that the pressure in the inner wall of the tubes was static earth pressure, introducing the membrane theory and considering the friction between geotubes and particles, the shape as well as the stress characteristics of the geotextile in the steady state were theoretically derived, and the effect of the friction effect and the lateral pressure coefficient to the characteristics of the geotextile was analyzed. The results showed a great influence of the friction effect on the relevant characteristics of the tubes, therefore it wasn’t negligible. When other conditions remained the same, the greater the friction coefficient was, the greater the maximum tension of geotextile would be and the shape of the geotextile would become flatter. The maximum tension of the geotextile tubes increased with the increasing of the earth pressure coefficient while the sensitivity of the shape of the geotextile to the lateral pressure coefficient was low, i.e. the lateral pressure coefficient hardly affected the shape of the geotextile.(3) The discrete element method was introduced into the study of geotextile tube, Calibration of the relevant parameters of the geotextile tubes in PFC2D,then using PFC2D simulatedmodel tests in the second chapter,from the view of the numerical simulation to verify the correctness of steady-state with geotubes, and simulating two conditions which were uniformly distributed load in the top and Two sand bags stacked, then we could get the sand bags’shape and tension distribution characteristics, and then we also could identify weak spots in the engineering of geotubes which was in the upper and lower at the separation point of the geotextile tubes.The innovation point of this paper was the theoretical analysis of the follow-up st age of the geotextile tubes in view of stabilization and the following algorithmic meth od in theoretical derivation by using the elements of both the friction coefficient and t he lateral pressure coefficient. The application of the discrete element method was als o used to make the verification of the conclusion in this paper much more powerful so that the theoretical directions were given to help the design of the geotextile tube and the process of constructions.