Some factors affecting the structural performance of reinforced fills spanning voids

The use of basal reinforcement to prevent the collapse of fills following the formation of a foundation void is becoming an accepted foundation engineering technique. To evaluate the various factors that affect the structural performance of reinforced fills spanning voids a parametric study was performed using continuum methods based on the finite difference technique. The study shows the major parameters that affect structural performance are void size, fill height, foundation type, reinforcement strength and reinforcement stiffness. The results demonstrate that while reinforcement strength and bond may be the two criteria governing collapse, unique combinations of void size, fill height, reinforcement strength and reinforcement stiffness are required to meet serviceability criteria. In particular, reinforcement stiffness alone can only enhance serviceability by a limited amount. Furthermore, the loads carried by the reinforcement are not in proportion to its stiffness as some of the simplified analytical procedures would suggest. Multiple reinforcement layers also may be used, however, their effect on serviceability is the same as a single reinforcement layer.