Active failure mechanism and earth pressure of narrow backfill behind retaining structures

Through a series of model tests accomplished by Particle Image Velocimetry analyses, this study presents the visualization of the displacement field of the narrow soil behind retaining structures under translational mode. The progressive development of failure mechanisms and active earth pressure are measured in the process of tests. Finite element limit analyses are supplementally carried out to investigate and verify the ultimate failure mechanism and active earth pressure acting on retaining structures as the tests. Furthermore, this study carried out parameter studies on the development of failure mechanisms and active earth pressure with different aspect ratios, inclinations of the existing structure, and backfill surface surcharge. Experimental and numerical results show a reasonable verification of each other. With the increase in backfill spacing, the failure mechanism of backfill turns from reflective shear bands into a single shear band, and the earth pressure exerted on the retaining structure increases.