Let's talk dirt! In construction, you must understand what type of soil you are dealing with. Whether it's size or behavior, the stability of your foundation and the safety of the crew and anyone onsite after the project is completed depend on the soil. Once you know the types of soil and their behaviors, you should also understand the acts of swelling and shrinking. Failing to account for soil movement and behavior can majorly impact the bidding process. Keep reading to learn about the various soil types to ensure a safe and stable worksite.

What are the classifications of soil?

Sand
Clay
Silt
Loam

The purpose of sand is not only to build a sand castle or provide you with the perfect place to relax oceanside, but it is also highly utilized in construction. Its particles are large, rough, and loose, making it perfect for drainage. However, it has lower cohesion. Cohesion is the sticking together of particles of the same substance. Due to this, sand is generally easy to excavate and therefore can be used for roads, retaining walls, and backfilling foundations. It should not be used for building the foundation of a high vertical structure, water structures, or slopes that require support, as it is too weak.

Clay, on the other hand, is a lot finer and has higher cohesion. It is a soil that can be molded when wet due to swelling, yet it will shrink when dry. Unlike sand, it has high water retention, leading to poor drainage. It is good for dams, canals, landfills, and embankments. It is not great for roads or foundations - especially in wet conditions.

Silt is like the middleman, with mid-sized particles and moderate-to-low cohesion. It is terrible for drainage purposes as it is easily eroded by water. Silt can be used as a fill material. It is highly used in the landscaping and agriculture industry. It is advised not to use it for foundations, roads, slopes, or embankments.

Loam soil is a mix of sand, clay, and silt. Loam is a softer soil with lower cohesion. Compared to sand, loam has better water retention, allowing excess water to drain away. It prevents root rot, making it perfect for agriculture or landscaping. Due to loam's shrinkage and swelling behavior, it is not ideal for structural construction. It can be used for topsoil covering, filling embankments, or used as a light backfill in road construction.

Understanding the behaviors and properties of each type of soil allows you to make smarter and safer decisions in construction. Using takeoffs can highly enhance your chances of winning the bidding process. Earthwork takeoffs are calculations on how much material is on the job site and what amounts will need to either be hauled away or brought in to fulfill the project’s requirements. Takeoffs estimate disposal costs, equipment needs, and the difficulty of labor. If you have any questions about the different types of soils or our services, please reach out to us at 877.572.3414 or email us at info@eci3d.com!