THE PROBLEM
A lagoon, located close to the city of Burgas, consisted of waste from the petroleum industry. It posed a serious health hazard as well as the environmental nuisance of noxious odours. It was directed that the lagoon needed to be provided with a safe capping.
THE SOLUTION
Tensar ground stabilisation geogrids were used to provide a mechanically stabilised layer (msl) to create a working platform and a permanent capping layer for the subsequent installation of a geosynthetics clay liner (gcl).
PROJECT DESCRIPTION
The typical depth of the waste lagoon was 3-4m and the capping was carried out in phases. In total, approximately 125,000m² of Tensar’s stiff ground stabilisation geogrids were used to support and mechanically stabilise a granular fill layer over the lagoon deposits. The method of fill placement is important when working over lagoons and care is needed to avoid punching into the sludge or the creation of mud waves. The ability of the geogrid to interlock effectively with the aggregate particles is important in achieving the necessary performance. In the permanent state the geogrids created a mechanically stabilised layer which is able to cap the lagoon deposits in a safe way. Once the capping was placed and regulated, a geosynthetics clay liner (gcl) was installed as a barrier against rain water infiltration and the escape of waste vapours. A final topsoil cover layer was then placed as part of the landscaping in this remediation project.
