Subsidence Evaluation of Geotextilereinforced Gravel Mats Bridging a Sinkhole

Compacted gravel mats, reinforced with layers of geosynthetic, are often used in areas prone to the occurrence of sinkholes. The purpose of the geosynthetic reinforcement is to bridge the cavities formed by the sinkholes. Since compaction of the overlying gravel inevitably involves the possibility of damaging the reinforcement, as well as higher costs, it is desirable to have a method of analysis that will provide a balance between cost and the best technical design. That is, enable the engineer to choose between a less compact gravel mat with a higher degree of reinforcement versus a more compact gravel mat containing less reinforcement. The present paper shows that, for a very dense gravel mat, geotextile reinforcement acts solely as a separator (it prevents the caving of the material into the sinkhole). For medium dense gravel mats, and gravel mats with a minimum degree of compaction, the geotextile reinforcement plays a more significant role in reducing the settlement at the surface of the gravel mat.