If you're not familiar with polyurethane soil stabilization, here's a basic overview excerpted from the brochure you can download at the bottom of this blog post:
Unstable soil can be defined as soil that will not stay in place on its own, and therefore requires extra support. It should be noted that unstable soil can threaten the stability, security, and safety of infrastructure and can damage, degrade, and even destroy a number of structures, such as buildings, bridges, and roads. There are a variety of factors that can cause unstable soil including erosion, poor compaction, freeze/thaw cycles and decomposition.
Soil can be stabilized with AP Soil 600, Spetec PUR H40, Spetec AG100 and Spetec AG200. Once the bearing capacity of the soil has been increased with this process, then the structure can be lifted if necessary.
For a detailed explanation of the process in a variety of settings, watch the animated video below...