Particle Size Distribution

 
Particle Size Distribution
The Particle Size Distribution (PSD) test is an important aspect of soil categorization and engineering behavior analysis. It determines the fraction of different-sized particles in a soil sample, resulting in a detailed grain size profile that affects permeability, strength, and compaction properties. Coarser particles are evaluated with the Sieve Analysis method (ASTM D6913 / BS 1377-2), whereas finer particles need Hydrometer Analysis (ASTM D7928). The combined data allows for categorization using systems like USCS and AASHTO, as well as guiding the selection of appropriate building methods and materials. PSD testing is used in almost every geotechnical engineering application, from filter compatibility and drainage capacity to identifying the appropriateness of materials for road foundation, embankments, and structural fill. PSD testing provides engineers with information that assist them improve design, reduce settlement risks, and assure the long-term performance of civil engineering projects.

Advantages of PSD testing:

• Provides soil grading and categorization.
• Supports permeability and stability analysis.
• Important for filter and embankment design.
• helps forecast compaction and load response.
• Suitable for both fine and coarse-grained soils.