The construction of a new embankment or structure induces additional stresses on the ground that can create unacceptable long term residual settlements during the life of the structure or highway. A preloading program can be designed to induce these settlements in an accelerated time frame and therefore minimize the long term residual settlement to within acceptable limits for the structure.

The Typical pre-consolidation program usually includes:

1. Installation of prefabricated vertical drains to the bottom of the compressible layer. Vertical Drains are installed on a grid pattern and to the depth required by the design.

2. Placement of the preloading embankment in phases (due to potential risk of slope failure) and additional temporary surcharge embankment as designed.

The real time evolution of the main geotechnical parameters (settlements, pore water pressure, horizontal displacements.) is monitored throughout the consolidation period. Instruments are installed to validate the design and the safe phasing of the construction of the embankment. The monitoring of the geotechnical parameters is also used to back analyze the main design hypothesis and results. The design parameters and calculations are optimized to fit the observed results and updated settlement and consolidation targets are used to assess the consolidation process.


  • Accelerates the consolidation of fine-grained soils.
  • Strengthens underlying soil to accommodate super-imposed loads.
  • Limits long-term settlement.