21/04/2026
Common Soil Types and Construction Behavior:
Rock (Bedrock, Limestone, Sandstone)
Behavior: Offers the highest stability and bearing capacity. It does not expand, shrink, or settle significantly.
Construction Use: Ideal for heavy structures. However, it is expensive and difficult to excavate.
Gravel and Sand (Non-Cohesive/Granular Soils)
Behavior: Large particles that allow for excellent drainage. They are stable when properly compacted but can shift or wash away (erosion) if unconfined.
Construction Use: Excellent for foundations and road bases because they don't hold water, reducing frost heave and settlement risks.
Clay (Cohesive Soil)
Behavior: Composed of very fine particles that hold water stubbornly. It is highly expansive, meaning it swells when wet and shrinks/cracks when dry, exerting massive pressure on foundations.
Construction Use: Challenging for construction; often requires deep foundations (like piles) to reach stable soil or chemical stabilization with lime or cement.
Silt
Behavior: Particles are larger than clay but smaller than sand. It retains moisture and drains poorly.
Construction Use: Prone to significant erosion and frost heave. It is considered moderately suitable but often needs reinforcement or replacement with better fill.
Peat and Organic Soils
Behavior: Composed of decaying vegetation; highly compressible, spongy, and weak.
Construction Use: Generally unsuitable for supporting structures. If encountered, it must typically be removed and replaced with stable fill or bypassed using deep piles.
Loam
Behavior: A balanced mix of sand, silt, and clay. It offers good drainage while maintaining stability.
Construction Use: Often considered the ideal soil type for foundations because it is easy to work with and resists extreme shifting.
