Design of reinforced fill systems over voids

Abstract

Embankment fill structures are often laid on formations that may develop cavities during their life-span. The use of geosynthetic reinforcement to mitigate the consequences of the formation of such cavities provides an appealing solution to the problem. To properly analyse the problem of reinforced fill overlying cavities, the reinforcement–fill interaction has to be properly addressed and modelled for a realistic solution to be reached. Typically, this problem has been approached by researchers using limit-equilibrium methods. Limited continuum analyses results are available for the problem. This paper presents the results of a systematic parametric continuum analysis that was carried out to study this problem. The parameters that govern the behaviour of reinforced fill systems were identified and varied within their typical ranges. The objective of the study is to provide a comprehensive set of design charts that give insight into the behaviour of reinforced fill systems and highlight the effect of each of the parameters that govern this behaviour. The charts are presented in simple formats that aid the engineer to estimate the expected settlements, reinforcement tension, and width of affected zone for different conditions, as well as obtain a feel for the interaction taking place between the various elements of the system. Key words : reinforced fill, tension membranes, geosynthetics, coral formations, karstic formations, sinkholes.