Bearing Capacity And Mechanism Of Subsoils Bed Reinforced With Horizontal-vertical Inclusions Under Strip Shallow Foundation

This study aims to investigate the potential benefits of using the horizontional and H-V reinforcements to improve the bearing capacity and to reduce the settlement of shallow foundations. To implement this objective, 11 model tests were performed to study the behaviors of reinforced subsoils. The experimental results show that the reinforcement can significantly improve the bearing capacity of the soil and reduce the footing settlement. The bearing capacity of the soil reinforced with H-V reinforcements is higher than that of the soil reinforced with horizontal reinforcements under the same conditions. The effects of the location and the number of reinforcement layers on the behavior of the soil are presented. The test results show that the bearing capacity decreases remarkably by increasing the top spacing. The test results clearly identify a critical zone between 0.3 B and 0.5B (where B is the width of the footing), and thereby maximum benefits of the bearing capacity of the foundation are obtained. Laboratory tests also show an increase of 180, 290, and 410% in bearing capacity of a strip foundation when one, two, and three layers of reinforcement were used, respectively. Good agreement is observed between Terzaghi's bearing-capacity equations and the experimental results. The test results indicate that the reinforced inclusion can redistribute the applied load to a wider area, thus minimizing stress concentration and achieving a more uniform stress distribution.Reinforcing mechanism and failure models of the soil reinforced with horizontional and H-V reinforcements were studied using PFC2D (Particle Flow Code in Two Dimensions). PFC2D analysis results indicate that reinforcement mechanisms of horizontional reinforcements are rigid boundary, membrane effect and lateral restraint effect. Furthermore, the confinement effect of vertical inclusions of H-V reinforcement can be developed. As a result, bearing capacity of the H-V reinforced soil is higher than tant using the horizontional one.Based on the tests and PFC2D results and using the limit equilibrium theory, foumlars of bearing capacity of horizontional and H-V reinforced foundations are developed for horizontional and H-V reinforced foundations. The results of proposed foumlars were compared with those obtained from the model tests. Good agreement was obtained.