Paving contractors can never really know what lies beneath their feet until their project begins. At the start of excavation, contractors can start to learn about the soil, dirt, and clay, and whether or not they foresee running into problems or obstacles. One common problem is unstable soil. This basically means that the dirt is too soft to provide a sufficient foundation for pavement installation. When this happens, pavers must find an alternative solution to get the job done right, and in a safe and reliable manner. Continue reading to learn what causes soil instability and how it affects a paving installation or excavation project.
Unstable Soil or Dirt
There are three main issues that cause unstable soil. Decomposing plant life and other organic matter loosen soil and diminish its stability. This is more prevalent when soil is near a body of water or some other source of water.
Another cause, or quality, of unstable soil is reduced compaction or lack of compaction capability. This means that the dirt cannot press into itself, making it stronger and more compact. This is especially common for hills and raised areas that were filled-in with dirt. If the soil is not compacted in thin layers, it cannot present a uniform and even appearance, nor provide a stable foundation for pavement.
The third, and most common, reason for unsteady soil is its make-up or composition. Mineral and element imbalances in dirt can inhibit its ability to compact or provide secure surfaces for asphalt. Soil requires a certain balance of air, water, minerals, and organic matter to be at its most stable. For example, if too much water or moisture is present, then soil becomes mud, which cannot be paved on; and it can take several days and even weeks for mud to dry. Not only would this cause extensive delays in construction, it would cost more money too.
The cause and solution for instable soil largely depends on the circumstance. All cases are different, and it is possible to find several different types of dirt in an excavation. Soil that is not usable must be fixed before any paving can occur.
Here are some solutions that have worked in the past to cure unstable dirt:
• Double-Check for Drainage Problems
• Use Drainage Tiles to Relieve Excess Moisture
• Till Soil to Expedite Drying Time
• Install Soil Separation Fabrics to Reduce Contact with Base Materials
• Install Geo-Grids
• Replace Soil with Proper Base Material in Subgrade
• Chemically-Treat the Soil to Enhance Stability
• Use Foam Asphalt Injections
• Contact a Licensed Asphalt Paving Company for Advice