Serviceability Limits for Basal Reinforced Embankments Spanning Voids

Geosynthetic reinforcement has been used as a form of insurance against the potential catastrophic collapse of embankments when voids form in the foundation below. Here, the geosynthetic reinforcement spans across the foundation void supporting the embankment fill. The strength of the reinforcement as well as its bond with the surrounding soil is considered to be of primary importance in this instance. However, of more importance in this application is the ability of the reinforcement to ensure the unsupported embankment remains in a serviceable condition. Serviceability, in this case, is normally expressed in terms of a differential deformation at the embankment surface. The serviceability problem is analyzed using continuum methods which have generated a large database of results. This database has been interrogated to generate the various serviceability relationships contained in the paper. The results show that serviceability, described in terms of surface differential deformation, can be related primarily to the embankment height to void width ratio, and secondarily to reinforcement tensile stiffness. Relationships between required reinforcement stiffness and associated tension are presented that enable the selection of appropriate geosynthetic reinforcements to achieve a required level of embankment serviceability.