Embankments on weak soils and areas prone to subsidence
Soft foundation soils or potential cavities under road or railway embankments can cause differential settlements and long-drawn-out consolidation, critical deformations or even insufficient global stability which may lead to deformations in the road or railway structure, stability failures or pose a risk of catastrophic failure. In order to minimize these problems, preventive measures may be necessary.
Allowing for consolidation can be a long process (> 25 years) in weak saturated soils under embankments, so to release water and therefore reduce pore water pressure, we must look to shorten the drainage path of the water held in the soil. Accelerated consolidation is achieved by the use of prefabricated vertical drains (PVD) to create shorter drainage pathways for groundwater.
Colbonddrain prefabricated vertical drain is a geocomposite that resists tears under load during installation to maintain its integrity and therefore maintain the drainage pathway. The outer filter fabrics are bonded to the core structure over its entire surface to form a homogeneous geocomposite product.
To drain off the saturated weak subsoil, increase the global stability immediately and get smaller and more even settlements the system of geosynthetic-encased columns (GEC) is another proven method. Due to the seamless finishing of Enka-Tube the undesirable mixing of the gravel material with surrounding weak soil is prevented.
Both applications are recommended to be combined with high-strength woven geotextiles as load distributer layers. Furthermore, in case of a sudden deformation of the subsurface due to cavities, the geosynthetic layer acts as membrane layer and mitigates against the risk of catastrophic failure.
Consolidation of soft soils is accelerated by using Enka-Tube or Colbonddrain. The additional high strenght Enka-Force acts as load distributor and membrane layer.
Full consolidation of weak soils can be achieved in months rather than years when using Colbonddrain prefabricated vertical drains (PVD).
Functions:
- Accelerating consolidation
- Increasing bearing capacity
- Improving embankment stability
Relevant products:
