On-Demand Webinars

THE USE AND MISUSE OF THE UNIFIED SOIL CLASSIFICATION SYSTEM:
Understanding Soil Classification in the Field

Learn how accurate soil classifications and other descriptive elements are essential for:

• Well screen design and placement
• Preparation of reliable potentiometric surface maps
• Ground water monitoring system design
• Excavation and foundation design.

Soil classification is fundamental for geotechnical and environmental site characterization, and the Unified Soil Classification System (USCS) is the classification used in North America. Unfortunately, the industry’s state-of-practice overlooks simple improvements to make the classification a useful characterization tool and often misuses the classification in site evaluation.

This 90-minute webinar begins with a brief historical perspective of the USCS followed by the step-wise procedures for classifying both coarse- and fine-grained sediments. Helpful tips are presented to make field classification easier and less confusing as well as to make the classification a better characterization tool by adding supplementary grain-size information, depositional environment interpretation, and site-stratigraphic unit information. Common ways the classification is misused are pointed out with helpful solutions.

This webinar will cover the following topics:

• Background of the USCS
• Coarse-Grained vs. Fine-Grained Sediments
• Laboratory Methods vs. Field Classification Techniques
• Particle Size Curves and how to understand them
• Poorly-Graded vs. Well-Graded
• Understand the Coefficient of Uniformity and the Coefficient of Curvature
• Lean Clay vs. Fat Clay vs. Silt
• Plasticity Chart and how it applies to fine-grained sediments
• Common mistakes and confusing terms.
• How the USCS applies to building the geologic framework, and how it doesn’t.
• A simple Case Study that illustrates stratigraphic context for soil classification.