The Investigation On Stability And Mechanism Of Embankment Reinforced With H-V Inclusions

Horizontal-Vertical (H-V) reinforcing element is a new type of 3D reinforcements, in which some vertical reinforcing elements were placed on the traditional horizontal inclusions to made the reinforcements. The results of triaxial tests and plain strain tests which had been carried out to investigate the behavior of soil reinforced with H-V inclusions have proved that the H-V reinforcing elements can improve the strength of soil and restrict the deformation of soil. In this dissertation the behavior of bearing capacity and mechanism of embankments reinforced with H-V inclusions were investigated by labortatory model tests, numerical simulations and theoretical analysis. The conclusions are available for reference practical application and related research of soil reinforced with H-V elements.A series of laboratory model tests had carried out on H-V reinforced embankment. In these model tests, the layer, length, and type of reinforcements and the size of footing were varied. The H-V reinforcing elements were proved in increasing the bearing capacity, reducing the settlements and restricting the lateral displacements of embankments, by the results of laboratory model tests. In model tests the bearing capacity of reinforced embankments were increased with the increment of the layers of H-V reinforcing elements. It can be found that the bearing capacity of embankments can be increased and the lateral displacements on top of the slop can be restricted more effectively, if the location of H-V reinforcing elements was closer to the footing in vertical direction. The short H-V reinforcing element was provided little lower increment in the bearing capacity of embankment but it can save material of reinforcements, according to this optimized design can be provided. The shear bands in H-V reinforced embankments were separated into several discontinuous arc bands by the reinforcing inclusions. The angle of the shear band was larger and the location was close to the middle of embankment.The PFC numerical simulations (Discrete Element Method) were carried out on the base of the results of model test. The working mechanism of H-V reinforced embankment was investigated by analyzing the contact force between soil particles and the displacement of ball units. When the embankment was under loading, besides the tensile force provided by the horizontal element, the vertical inclusions provided resistance to restrict the lateral displacements of soil. Soil near the H-V inclusions was been strengthened, and these"strengthened areas"made the stresses evenly distributed in filling. The shear bands obtained by the numerical simulations were in common with those observed from model tests. Most soil particles moved horizontally in the slope of the embankment, so the vertical inclusions of H-V reinforcing elements worked effectively and restricted the lateral displacement of the slop.By analyzing the result of laboratory model tests and PFC numerical simulations on embankments reinforced with H-V inclusions, the traditional equation to calculate the safe factor of reinforced embankments was been revised. The new equation is suit for calculate the safe factor of embankments reinforced with H-V inclusions, which considering the effect of both horizontal elements and vertical inclusions.