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.

The Causes of Unstable Soil

Erosion
Poor drainage, improperly placed downspouts, leaking drain pipes, and broken water lines are common culprits.

Poor Compaction
When backfilling on a job site, the contractor is supposed to compact the backfill by driving over it with heavy equipment. However, this isn’t always done properly for one reason or another.

Freeze/Thaw
Processes of freezing and thawing essentially accelerate erosion processes. Cold weather freezes moisture trapped in tiny cracks. When this water freezes, it expands, subsequently pushing on the rocks and breaking them into smaller pieces. As processes of freezing and thawing continue, rock and sediment are continually broken down.

Biological Decay
Construction trash pits, buried trees, and other biodegradable materials all break down. Sometimes structures are built over these areas.

Stabilize Soil with Polyurethane

Loose soil can be consolidated, voids can be filled, and water migration halted by permeating the soil with one of the AP series products of ultra-low viscosity polyurethane resins. Once the bearing capacity of the soil has been increased with this process, then the structure can be lifted if necessary.  Learn more about Soil Stabilization Products here.

Want more information on polyurethane soil stabilization?