Soil Stabilization & Void Filling

Soil Stabilization & Void Filling

Soil Densification or Soil Stabilization is a process of injecting specialized expanding polyurethane grouts to firm up and strengthen weak and/or shifting soils in order to gain superior strength to eliminate erosion or to allow higher load bearing capacity.

Weak/loose soils & eroding soils around and under structures will eventually undermine a structures’ foundation or worse, allow it to breach and possibly break and separate.  Once development begins on weak/loose soils, structural failure is almost certainly inevitable. Upon building a structure, these soils begin to slowly compact against the weight of the structure and sometimes they need help in supporting the newly introduced loads to eliminate settlement.

The technology and methodology of building has changed dramatically over the last 10-20 years. Now, typically, soils are tested prior to construction to determine the density and composition in relation to the support characteristics needed for the proposed structure to be built. Prior to this time frame, testing was not accomplished and we can begin to see the stresses (cracks) in some structures from older construction.

Hydrophobic polyurethane grouts are injected directly into soft soils to provide a glue-like bond of weak or shifting soils. They can be injected to depths of up to 30 to 40 feet to provide a very secure base; and they can also be applied prior to construction and they have the capability of turning ordinary “ball-bearing” type contractor fill dirt into 700 – 1200 p.s.i. bonded soil (depending on soil types)… sort of like turning your soil into a lightweight concrete.

Hydrophobic polyurethane grouts are activated by moisture, and they displace and vacate water during injection. Even swamp-like soil conditions can be bonded to provide load bearing, structural strength. And they cure to 90% load capacity in less than an hour.  Other types of polyurethane grouts can be hydrophilic or 2 component.

There are two different types of grouting processes used for the purpose of Soil Solidification & Soil Stabilization:

compactionCompaction Grouting is a process by which rapidly expanding polyurethane grouts (fully expanded in 30-60 seconds) are injected into the ground to fill voids in the immediate area and compact the surrounding soil using expansive pressure.   The grout fills voids in the immediate area, fractures the soil with lenses and veins of resins, and compacts the surrounding soil using expansive pressure.

Permeation Grouting is a process where liquid resin is injected into the ground so that the resin permeates and saturates the soil before reacting. Using a low-viscosity chemical grout, the resin is able to flow into the pores of the soil without displacing or changing the soil structure. Once cured, the grout “glues and binds” the soil particles together.  The soil and resin form a strong, solid, impermeable mass that increases the load bearing capacity of the soil.

Typical structures include:

• roads / highways • bridges • dams • patios • driveways • foundations • bridges • airports • catch basins • walkways • pools • porches


• Less time • Less cost • Less disruption • Less environmental impact


Note:  In highway projects, roadways can often remain open to traffic.

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