Which soil classification system is Internationally recognized for geotechnical purposes?

The Unified Soil Classification System (USCS) is an internationally recognized system for classifying soils for geotechnical purposes. It provides a consistent methodology for identifying soil properties based on their physical characteristics, which is essential for engineers and builders in designing safe and effective structures.

The USCS categorizes soils into major groups based on particle size, grain shape, and their plasticity, which allows engineers to make informed decisions regarding soil stability, drainage, and compaction. This standardization is crucial in construction, as it ensures that engineers worldwide can communicate effectively and understand the soil conditions they may encounter.

The AASHTO Classification System, while used primarily in highway and transportation projects in the United States, does not have the same international recognition as the USCS. Although it is valuable for classifying soil types in specific contexts, it does not offer the same level of global applicability as the USCS.

Both the USCS and the AASHTO methods serve important roles, but the USCS stands out as the clear choice for international geotechnical applications. Therefore, recognizing the USCS alongside its alternative—when both are considered under the choices—demonstrates an understanding of both systems and their respective uses in engineering.