Soil Stabilization

 
Construction of paved roads and unpaved access roads has been greatly benefited by the use of geotextiles. ALYAF geotextiles through the functions of separation, filtration, reinforcement and transmissivity help in:
  • Maintaining the integrity and the functioning quality of the structural layers.
  • Allow the use of free draining base course materials.
  • Distribute load over a wider area thereby increasing the bearing capacity of sub grades.
  • Permit cost-effective construction over weak soils and saturated sub grades.
  •  Increase the payment life.
The greatest benefit of ALYAF geotextiles in road pavements has been as a separator between the base course or sub base and sub grade. In the absence of ALYAF, intermixing of the base and sub grade occur under the influence of traffic loading and the pumping of fines from the sub grade into the base course. This contamination of the base course aggregate causes a net reduction of base course thickness and weakening of that layer

With ALYAF geotextile acting as a seperation layer at the interface of the subgrade and the base course, the subbase/base course is completely seperated from the subgrade soil fines,therefore the designed base course thickness and its properties are maintained throughout the life of the project.





Construction Over Saturated Subgrades :
Drainage of water from pavements has always been an important consideration in road design; however current methods of design have resulted in base courses that do not drain well. The problem has been compounded with the rise in the water table. water rises up into the base course through pore water pressures and through capilary function leading to saturation of the base courses. saturation of the base course changes the dynamics of vertical stress distribution, and may allow transfer of traffic loads directly to subgrade soil, eliminating the benefits of the structural layers leading to rapid pavement damage.

To adequately address ground water drainage the designer needs to consider providing ALYAF geotextils enclosed subsoil drainage systems (blanket drains) that will lead the ground water away from the pavement structure layers and also prevent the capillary rise of the ground water into the structural layers
 

















ALYAF being used for soil stabilization at the King Abdullah Economic City


ALYAF being used for soil stabilization at Abu Hadria Expressway 




Load deformation curves for soaked sabkha soil with and without ALYAF

Source:Dr.Saad Aibaan et all, Reinforcement of Saudi Sabkha Soil, KFUPM