Properties Of Grid-reinforced Retaining Wall

Reinforced retaining wall’s failure surface, grid tensile force, soil pressure, deformation are important in designing reinforced retaining walls. However, many present retaining walls are designed empirically. This article researches into grid-reinforced retaining wall through theoretical analysis, numerical simulation, model experiment, and field experiment.Research finds that failure surface of reinforced retaining wall is caused by upward stress and downward stress and the superimposition of these two stresses. Failure surface caused by upward stress usually composes of two segments of straight lines. Lower half of the failure surface extends obliquely upward starting from wall footing and assumes an included angle of45°+0.5φ with horizontal plane. Failure surface exhibits a linear relationship with vertical pressure. The bigger the vertical pressure is, the longer the failure surface will be. The bigger the wall-top pressure is, the higher the upper half of failure surface, which extends obliquely to wall plane starting from the top of lower half of failure surface, will be. Failure surface caused by downward stress is a straight line produced at a certain position on wall plane and extends obliquely downward and assumes an included angle of45°+0.5φ with horizontal plane. This article summarizes a set of methods for calculating and drawing failure surfaces quickly.Lateral earth pressure at the back of reinforced retaining wall is basically identical with the theoretically calculated static soil pressure. Checking of retaining wall’s overall stability can be performed with earth pressure at rest at the back of wall. After dynamic compaction, lateral earth pressure at the back of reinforced retaining wall increases significantly. Due to the fact that grids’effect inside reinforced soil diminishes gradually, the included angle between failure surface and horizontal plane decreases gradually starting from bottom to top. Under identical conditions, compared with upright reinforced retaining wall, wall plane displacement and wall-top plane’s differential settlement of inclined reinforced retaining wall are small. Foundation of retaining wall exerts big influence on wall plane displacement and wall-top plane’s differential settlement.Failure surface at lower half of inclined retaining wall inclines with the incline of wall plane. The greatest wall plane displacement is at1/3of wall height, Bulging of wall appears. With the increase of wall-top load, horizontal displacement of wall plane tends to increase, and horizontal displacement of upper wall plane becomes more significant. Dynamic compaction close to retaining wall will cause big vibration acceleration to wall plane, especially horizontal acceleration of wall top. The closer the compacting spot is to wall plane, the more significant the increase of vibration acceleration will be. Dynamic compaction can increase grid tensile force. Heavy hammer and low drop can reduce the influence of dynamic compaction on grids. Rolling load can cause big horizontal displacement to middle and lower parts of wall plane. Dynamic compaction make plane of compacted reinforced retaining wall retract. Theories, experiment methods, and conclusions in this article can provide reference for further research and design of retaining walls.