Reinforcement Over Cavities
Securing Areas at Risk of Subsidence
In areas prone to cavities, such as in carstic zones or old mines, sudden collapse can be prevented where high strength geosynthetics are used to reinforce road embankments or base courses. Geosynthetics reinforce and prevent the collapse of the structure, ensuring safety for the users. Depending on the size of the cavity and the thickness of the structure the reinforcement limits or avoids settlement at the surface for the design lifetime of the structure.
With geosynthetics the needed quantity of granular fill material decreases, providing significant cost reductions and limitation of environmental footprints.
Reinforcement and Monitoring
When using reinforcing geosynthetics to avoid surface settlement when voids collapse, it is difficult to know when this collapse has occurred. If the void were to grow over a long period, it would be in the interest of the engineer to be aware of the collapse and to be able to decide whether remedial action was required. To assist with monitoring these critical structures the installation of the TenCate GeoDetect® system is recommended. TenCate GeoDetect® is integral with the reinforcement and measures the direct strain in that reinforcement transmitting a warning signal once the geosynthetic reaches a preset elongation limit.
TenCate Geosynthetics for Reinforcement Purposes
TenCate Mirafi® (wovens), TenCate Miragrid® (geogrids) and TenCate Polyfelt® (composites), made from the best performing polymer, are perfectly adapted to reinforcement over cavities:
- Strength up to 1600 kN/m to ensure the embankment stability
- High stiffness modulus to control the deformation and surface settlement
- Long term properties to insure the performance over the lifetime of the structure
- Form of supply adapted to the application:
1. Long and wide rolls
2. Custom made rolls to facilitate installation
Thanks to the participation at the research project RAFAEL (1997-1998) and the use of the resulting method design in several guidelines over Europe, TenCate acquired a great deal of knowledge in the use of geosynthetic spanning of voids. This experience was completed by numerous construction projects over cavities where TenCate geosynthetics were installed.
With the addition of TenCate GeoDetect®, we offer a complete geosynthetic and monitoring system with all the related service for design and installation assistance.
Products used for reinforcement over cavities:
1) TenCate Mirafi® PET High Strength Geotextile
2) TenCate Miragrid® GX Geogrid
TenCate Polyfelt® PEC Composite Geotextile