Study On Geotextile Bags Of Silt Embankment Deformation Properties At Wenzhou Shoal Area

The bags of silt embankment dig silt shoal area directly to fill the geotextile bags through the filler, after reaching design strength to step by step filling embankment and form the dam eventually. This kind of poor engineering properties of silt as the body of the dam of materials, and combined the geotextile bags of reinforced soil conservation function, to form the structures of structural strength. At present the technology is still in the test stage, the theoretical study and deformation characteristics analysis of the bags of silt embankment is still very rare. In this paper, based on the test engineering of land reclamation and soft foundation treatment (A1) engineering in Cangnan County, and combining with the reinforcement mechanism, geotextile bags packing characteristics, soil consolidation mechanism, reinforced soil stability calculation with the finite element method, carting out theory of silt embankment bags and deformation characteristics. The specific research results are as follows:(1)Through analyzing source of strength of the bags of silt embankment,to come up with that the early strength of bags of silt embankment is mainly provide by reinforced soil conservation of geotextile bags, the late strength by the consolidation of soil structural.(2) Through analyzing the stress of the geotextile bags, describing the geometry of the packing bag equations is established and getting numerical solution by Matlab. Found a logarithmic relation between the heights of the packing bag and pump pressure, an exponential relationship between the width of contact area and pump pressure, a linear relationship between geotextile bag tension and pump pressure. Combined with the large scale geotextile bag filling shape, to establish calculation formula of a single geotextile bag tension.(3) Through the optimization analysis by an example, establishing the finite element model of the test section, analyzing soft soil model and the mohr-coulomb model simulation results, getting the following conclusions:In the dam width, the basal surface vertical displacement is down and gradually increasing as the filling. Beyond the dam width, the basal surface produced a certain amount of uplift, and as the filling, the uplift and compression of the boundary moving away from the dam axis gradually. The basal surface horizontal displacement presents opening downward parabola distribution in the process of embankment construction and the horizontal displacement increase speed is smaller from the dam axis 9m. Vertical displacement decreases with the increase of the depth of section, and vertical displacement of the same depth increases rapidly in the process of filling. Horizontal displacement of the cross section depth was increased first, and then decreased with the increase of the depth of section. As the filling, sections of the same depth of each point of horizontal displacement are increased.Soils are calculated by use of a soft soil model of super static pore water pressure dissipation quickly. After a year,the result of pore water pressure is 2.7 KN/m, mohr-coulomb model calculation is 5.2 KN/m2, and very close to the measured 4.4 KN/m2.The bag body axial force decreases with the increase of distance from the dam axis. Basal plane bag body axial force increased slightly and axial force increase speed decreases as the filling.(4) To calculate the stability of bags of silt dam based on the strength reduction finite element method, found that reinforced bar point’s method is not applicable to calculate the stability of reinforced soil.